model 821fj lighting system trainer service manual information 2003 chevrolet impala vin w

Model 821FJ

Lighting System Trainer

Service Manual Information

2003 Chevrolet Impala

VIN W

Published by ATech Training, Inc. 12290 Chandler Drive

Walton, KY 41094 USA Phone: (859) 485-7299 Fax: (859) 485-7299

Email: [email protected] Website: www.atechtraining.com

Copyright 2009, ATech Training, Inc. All Service Manual Information © General Motors Corporation

Body and Accessories

Wiring Systems Data Link Communications Lighting Systems Body Control Systems Theft Deterrent

Wiring Systems

Diagnostic Information and Procedures


Circuit Testing

Circuit Testing

Probing Electrical Connectors Troubleshooting with a Digital Multimeter Troubleshooting with a Test Lamp Measuring Voltage Measuring Voltage Drop Testing for Continuity Testing for Short to Ground Testing for a Short to Voltage

Probing Electrical Connectors

Important: Always be sure to reinstall the connector position assurance (CPA) and terminal position assurance (TPA) when reconnecting connectors or replacing terminals.

Frontprobe

Disconnect the connector and probe the terminals from the mating side (front) of the connector.

Notice: Do not insert test equipment probes (DVOM etc.) into any connector or fuse block terminal. The diameter of the test probes will deform most terminals. A deformed terminal will cause a poor connection, which will result in a system failure. Always use the J-35616 GM-Approved Terminal Test Kit in order to front probe terminals. Do not use paper clips or other substitutes to probe terminals.

When using the J-35616 GM-Approved Terminal Test Kit, ensure the terminal test adapter choice is the correct size for the connector terminal. Do not visually choose the terminal test adapter because some connector terminal cavities may appear larger than the actual terminal in the cavity. Using a larger terminal test adapter will damage the terminal. Refer to the J-35616 GM-Approved Terminal Test Kit label on the inside of the J-35616 GM-Approved Terminal Test Kit for the correct adapter along with the connector end view for terminal size.

Important: When probing female 0.64 terminals, it is important to use the correct adapter. There have been some revisions to the test adapter for 0.64 terminals. The proper adapter for 0.64 terminals is the J 35616-64B which has a gold terminal and a black wire between the base and tip. Failure to use the proper test adapter may result in damage to the terminal being tested and improper diagnosis.

Important: The proper adapter for probing the terminals for fuses, relays, or diodes in an electrical center is J 35616-35. Using any other tool or adapter may damage the terminal being tested.

Refer to the following table as a guide in selecting the correct test adapter for front probing connectors:

Test Adapter Description J-35616-2A 150 Male Probe Adapter (gray)

J-35616-3 150 Female Probe Adapter (gray)

J-35616-4A 280 Male Probe Adapter (purple)

J-35616-5 280 Female Probe Adapter (purple)

J-35616-6 100W Male (round) Probe Adapter (brown)

J-35616-7 100W Female (round) Probe Adapter (brown)

J-35616-8 Weather Pack Male Probe Adapter (orange)

J-35616-9 Weather Pack Female Probe Adapter (orange)

J-35616-10 100W Male (round) Probe Adapter (green)

J-35616-11 100W Female (round) Probe Adapter (green)

J-35616-12 130 Male Probe Adapter (blue)

J-35616-13 130 Female Probe Adapter (blue)

J-35616-14 150 Male Probe Adapter (green)

J-35616-16 100 Male Probe Adapter (lt green)

J-35616-17 100 Female Probe Adapter (lt green)

J-35616-18 220 Male Probe Adapter (black)

J-35616-19 220 Female Probe Adapter (black)

J-35616-21 950 Female Probe Adapter (red)

J-35616-22 950 Male Probe Adapter (red)

J-35616-31 500 Male Probe Adapter (orange)

J-35616-32 500 Female Probe Adapter (orange)

J-35616-33 160/180 Male Probe Adapter (yellow)

J-35616-34 160/180 Female Probe Adapter (yellow)

J-35616-35 280 Male Probe Adapter (violet)

J-35616-40 480 Male Probe Adapter (dk blue)

J-35616-41 480 Female Probe Adapter (dk blue)

J-35616-42 630 Male Probe Adapter (red)

J-35616-43 630 Female Probe Adapter (red)

J-35616-44 800 Male Probe Adapter (yellow)

J-35616-45 800 Female Probe Adapter (yellow)

J-35616-54 280 Male (round) Probe Adapter (tan)

J-35616-55 280 Female (round) Probe Adapter (tan)

J-35616-64B 0.64 Male Probe Adapter (lt blue)

J-35616-65B 0.64 Female Probe Adapter (lt blue)

J-35616-66 150 Male (round) Probe Adapter (yellow)

J-35616-67 150 Female (round) Probe Adapter (yellow)

Backprobe

Important:

• Backprobe connector terminals only when specifically required in diagnostic procedures.

• Do not backprobe a sealed (Weather Pack®) connector, less than a 280 series Metri-Pack connector, a Micro-Pack connector, or a flat wire (dock and lock) connector.

• Backprobing can be a source of damage to connector terminals. Use care in order to avoid deforming the terminal, either by forcing the test probe too far into the cavity or by using too large of a test probe.

• After backprobing any connector, inspect for terminal damage. If terminal damage is suspected, test for proper terminal contact.

Do not disconnect the connector and probe the terminals from the harness side (back) of the connector.

Troubleshooting with a Digital Multimeter



Important: Circuits which include any solid state control modules, such as the powertrain control module (PCM), should only be tested with a 10 MΩ or higher impedance digital multimeter such as the J 39200 Digital Multimeter (DMM).

The J 39200 instruction manual is a good source of information and should be read thoroughly upon receipt of the DMM as well as kept on hand for future reference.

A DMM should be used instead of a test lamp in order to test for voltage in high impedance circuits. While a test lamp shows whether voltage is present if the impedance is low enough, a DMM indicates how much voltage is present. In other words, if there is not enough current, the test lamp will not illuminate even though voltage is present.

The ohmmeter function on a DMM shows how much resistance exists between 2 points along a circuit. Low resistance in a circuit means good continuity.

Important: Disconnect the power feed from the suspect circuit when measuring resistance with a DMM. This prevents incorrect readings. DMMs apply such a small voltage to measure resistance that the presence of voltages can upset a resistance reading.

Diodes and solid state components in a circuit can cause a DMM to display a false reading. To find out if a component is affecting a measurement take a reading once, then reverse the leads and take a second reading. If the readings differ the solid state component is affecting the measurement.

Following are examples of the various methods of connecting the DMM to the circuit to be tested:

• Backprobe both ends of the connector and either hold the leads in place while manipulating the connector or tape the leads to the harness for continuous monitoring while you perform other operations or test driving. Refer to Probing Electrical Connectors.

• Disconnect the harness at both ends of the suspected circuit where it connects either to a component or to other harnesses.

• If the system that is being diagnosed has a specified pinout or breakout box, it may be used in order to simplify connecting the DMM to the circuit or for testing multiple circuits quickly.

Troubleshooting with a Test Lamp

Special Tools

J 35616-200 Test Light - Probe Kit



A test lamp can simply and quickly test a low impedance circuit for voltage. A DMM should be used instead of a test lamp in order to test for voltage in high impedance circuits. While a test lamp shows whether voltage is present if the impedance is low enough, a DMM indicates how much voltage is present. In other words, if there is not enough current, the test lamp will not illuminate even though voltage is present.

The J 35616-200 is Micro-Pack compatible and comprised of a 12-volt light bulb with an attached pair of leads.

To properly operate this tool use the following procedures.

When testing for voltage:

1. Attach one lead to ground. 2. Touch the other lead to various points along the circuit where voltage should

be present. 3. When the bulb illuminates, there is voltage at the point being tested.

When testing for ground:

1. Attach one lead to battery positive voltage. 2. Touch the other lead to various points along the circuit where ground should

be present. 3. When the bulb illuminates, there is ground at the point being tested.

Measuring Voltage Notice: Do not insert test equipment probes (DVOM etc.) into any connector or fuse block terminal. The diameter of the test probes will deform most terminals. A deformed terminal will cause a poor connection, which will result in a system failure. Always use the J-35616 GM-Approved Terminal Test Kit in order to front probe terminals. Do not use paper clips or other substitutes to probe terminals.


The following procedure measures the voltage at a selected point in a circuit.

1. Disconnect the electrical harness connector for the circuit being tested, if necessary. 2. Enable the circuit and/or system being tested. Use the following methods:

3. Select the V (AC) or V (DC) position on the DMM. 4. Connect the positive lead of the DMM to the point of the circuit to be tested. 5. Connect the negative lead of the DMM to a good ground. 6. The DMM displays the voltage measured at that point.

• Turn ON the ignition, with the engine OFF.

• Turn ON the engine.

• Turn ON the circuit and/or system with a scan tool in Output Controls.

• Turn ON the switch for the circuit and/or system being tested.

Measuring Voltage Drop Notice: Do not insert test equipment probes (DVOM etc.) into any connector or fuse block terminal. The diameter of the test probes will deform most terminals. A deformed terminal will cause a poor connection, which will result in a system failure. Always use the J-35616 GM-Approved Terminal Test Kit in order to front probe terminals. Do not use paper clips or other substitutes to probe terminals.


The following procedure determines the difference in voltage potential between 2 points.

1. Set the rotary dial of the DMM to the V (DC) position. 2. Connect the positive lead of the DMM to one point of the circuit to be tested. 3. Connect the negative lead of the DMM to the other point of the circuit. 4. Operate the circuit. 5. The DMM displays the difference in voltage between the 2 points.

Testing for Continuity Notice: Do not insert test equipment probes (DVOM etc.) into any connector or fuse block terminal. The diameter of the test probes will deform most terminals. A deformed terminal will cause a poor connection, which will result in a system failure. Always use the J-35616 GM-Approved Terminal Test Kit in order to front probe terminals. Do not use paper clips or other substitutes to probe terminals.


The following procedures verify good continuity in a circuit.

With a DMM

1. Set the rotary dial of the DMM to the ohm position. 2. Disconnect the power feed (i.e. fuse, control module) from the suspect circuit. 3. Disconnect the load. 4. Press the MIN MAX button on the DMM. 5. Connect one lead of the DMM to one end of the circuit to be tested. 6. Connect the other lead of the DMM to the other end of the circuit. 7. If the DMM displays low or no resistance, the circuit has good continuity.

With a Test Lamp

Important: Only use the test lamp procedure on low impedance power and ground circuits.

1. Remove the power feed (i.e. fuse, control module) from the suspect circuit. 2. Disconnect the load. 3. Connect one lead of the test lamp to one end of the circuit to be tested. 4. Connect the other lead of the test lamp to battery positive voltage. 5. Connect the other end of the circuit to ground. 6. If the test lamp illuminates (full intensity), then the circuit has good continuity.

Testing for Short to Ground Notice: Do not insert test equipment probes (DVOM etc.) into any connector or fuse block terminal. The diameter of the test probes will deform most terminals. A deformed terminal will cause a poor connection, which will result in a system failure. Always use the J-35616 GM-Approved Terminal Test Kit in order to front probe terminals. Do not use paper clips or other substitutes to probe terminals.


The following procedures test for a short to ground in a circuit.

With a DMM

1. Remove the power feed (i.e. fuse, control module) from the suspect circuit. 2. Disconnect the load. 3. Set the rotary dial of the DMM to the ohm position. 4. Connect one lead of the DMM to one end of the circuit to be tested. 5. Connect the other lead of the DMM to a good ground. 6. If the DMM does NOT display infinite resistance (OL), there is a short to ground in the circuit.

With a Test Lamp

1. Remove the power feed (i.e. fuse, control module) from the suspect circuit. 2. Disconnect the load. 3. Connect one lead of the test lamp to battery positive voltage. 4. Connect the other lead of the test lamp to one end of the circuit to be tested. 5. If the test lamp illuminates, there is a short to ground in the circuit.

Fuse Powering Several Loads

1. Review the system schematic and locate the fuse that is open. 2. Open the first connector or switch leading from the fuse to each load. 3. Connect a DMM across the fuse terminals (be sure that the fuse is powered).

4. Close each connector or switch until the DMM displays voltage in order to find which circuit is shorted.

• When the DMM displays voltage the short is in the wiring leading to the first connector or switch.

• If the DMM does not display voltage refer to the next step.

Testing for a Short to Voltage



The following procedure tests for a short to voltage in a circuit.

1. Set the rotary dial of the DMM to the V (DC) position. 2. Connect the positive lead of the DMM to one end of the circuit to be tested. 3. Connect the negative lead of the DMM to a good ground. 4. Turn ON the ignition and operate all accessories. 5. If the voltage measured is greater than 1 volt, there is a short to voltage in the circuit.

Data Link Communications

Specifications Schematic and Routing Diagrams Component Locator Diagnostic Information and Procedures Repair Instructions Description and Operation

Specifications

Fastener Tightening Specifications

Fastener Tightening Specifications Specification

Application Metric English Data Link Connector Screw 2 N·m 18 lb in

Schematic and Routing Diagrams

Data Link Communications Schematic Icons Data Link Connector Schematics

Data Link Communications Schematic Icons Icon Icon Definition

Caution: When performing service on or near the SIR components or the SIR wiring, the SIR system must be disabled. Refer to SIR Disabling and Enabling . Failure to observe the correct procedure could cause deployment of the SIR components, personal injury, or unnecessary SIR system repairs.

Data

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Component Locator

Data Link Communications Component Views Data Link Communications End Views

Data Link Communications Component Views

Lower Center of Instrument Panel Left Side of Instrument Panel Support

Lower Center of Instrument Panel (w/o 9C1/9C3)

(1) G203

(2) Inflatable Restraint Steering Wheel Module Coil Connector C1

(3) Data Link Connector (DLC)

(4) C201

(5) Stop Lamp Switch Connectors

(6) Cruise Control Release Switch Connector

(7) Cruise Control Release Switch

(8) G201

Left Side of Instrument Panel Support

(1) Instrument Panel Carrier

(2) C205 (Radio Coax)

(3) Splice Pack-SP205 (Taped Over)

(4) Footwell Courtesy Lamp-Left

(5) Rear Compartment Lid Release Switch Connector

(6) Junction Block-Left I/P Connector C1

(7) Junction Block-Left I/P

(8) Traction Control Switch (Impala) Connector

(9) Fog Lamp Switch Connector

(10) Headlamp Switch Connector

Data Link Communications Connector End Views

Data Link Connector (DLC)

Connector Part Information • 12110250

• 16-Way F Metri-Pack 150 (BLK) Pin Wire Color Circuit No. Function

1 -- -- Not Used

2 PPL 1132 DLC Class 2 Serial Data

3 -- -- Not Used

4 BLK 1050 Ground

5 BLK/WHT 1251 Ground

6-15 -- -- Not Used

16 ORN 2140 Battery Positive Voltage

Connector Part Information

• 12191216

• 12-Way F GT 150 Splice Saver (GRY)

Pin Wire Color Circuit

No. Function A PPL 1132 DLC Class 2 Serial Data

B DK GRN 1049 PCM Class 2 Serial Data

C PPL 1807 Class 2 Serial Data - Primary (w/o 9C1/9C6)

D ORN 1044 Radio Class 2 Serial Data

E LT BLU 1122 ABS/TCS Class 2 Serial Data

F DK BLU 1128 SDM Class 2 Serial Data

G GRY 1036 IPC Class 2 Serial Data

H-J -- -- Not Used

K YEL 1127 Trip Computer Class 2 Serial Data (w/o 9C1/9C6)

L DK BLU 2272 Amplifier Class 2 Serial Data (W/U2K)

M LT GRN 1037 BCM Class 2 Serial Data

Splice Pack-SP205


Diagnostic Starting Point – Data Link Communications Diagnostic Trouble Code (DTC) List DTC U1000 and U1255 DTC U1001 – U1254 DTC U1300, U1301, and U1305 Scan Tool Does Not Power Up Scan Tool Does Not Communicate with Class 2 Device

Diagnostic Starting Point - Data Link Communications

Begin the diagnosis of the data link communications by performing the Diagnostic System Check for the system in which the customer concern is apparent. The Diagnostic System Check will direct you to the correct procedure within the Data Link Communications section when a communication malfunction is present.

Diagnostic Trouble Code (DTC) List DTC Diagnostic Procedure Module(s) U1000 DTC U1000 and U1255 BCM, DIC, IPC, Radio, OnStar Module, SDM

U1016 DTC U1001-U1254 BCM, DIC, EBCM, IPC, OnStar Module, SDM

U1040 DTC U1001-U1254 BCM, DIC, IPC, PCM, SDM

U1064 DTC U1001-U1254 DIC, IPC, Radio, PCM, SDM, OnStar Module

U1088 DTC U1001-U1254 IPC, OnStar Module

U1096 DTC U1001-U1254 DIC, OnStar Module, SDM

U1128 DTC U1001-U1254 OnStar Module

U1255 DTC U1000 and U1255 EBCM, PCM

U1300 DTC U1300, U1301, or U1305 BCM, DIC, EBCM, OnStar Module, PCM, Radio, SDM,



DTC U1000 and U1255

Circuit Description

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. When a module receives a message for a critical operating parameter, the module records the identification number of the module which sent the message for State of Health monitoring. A critical operating parameter is one which, when not received, requires that the module use a default value for that parameter. When a module does not associate an identification number with at least 1 critical parameter within about 5 seconds of beginning serial data communication, DTC U1000 or U1255 is set. When more than one critical parameter does not have an identification number associated with it, the DTC will only be reported once.

Conditions for Running the DTC

• Voltage supplied to the module is in the normal operating voltage range of 9 to 16 volts.

• Diagnostic trouble codes U1300, U1301 and U1305 do not have a current status.

• The vehicle power mode requires serial data communication to occur.

Conditions for Setting the DTC

At least one critical operating parameter has not been associated with an identification number within about 5 seconds after beginning serial data communication.

Action Taken When the DTC Sets

The module uses a default value for the missing parameter.

Conditions for Clearing the DTC

• A current DTC clears when the malfunction is no longer present.

• A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Diagnostic Aids

When a malfunction such as an open fuse to a module occurs while modules are communicating, a Lost Communication DTC is set as a current DTC. When the modules stop communicating the current Lost Communication DTC is cleared but the history DTC remains. When the modules begin to communicate again, the module with the open fuse will not be learned by the other modules so DTC U1000 or U1255 is set current by the other modules. If the malfunction occurs when the modules are not communicating, only DTC U1000 or U1255 is set.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. A Lost Communication with XXX DTC with a history status may indicate the cause of U1000 or U1255.

2. The module which is not communicating is the likely cause of U1000 or U1255 being set. The following modules communicate on the class 2 serial data circuit:

• Auxiliary Power Drop Connector

• BCM

• DIC

• DRR (U2K or U2L)

• EBCM

• IPC

• PCM

• Radio

• SDM

• OnStar (UE1)

5. The module which was not communicating may have set Lost Communication with XXX DTCs for those modules that it was monitoring.



11. The modules which can communicate indicate the module which cannot communicate. You must clear the DTC from these modules to avoid future misdiagnosis.

13. If all modules are communicating, the module which set U1000 or U1255 may have done so due to some other condition.

14. The module which set U1000 or U1255 is the likely cause of the malfunction.

Step Action Yes No Schematic Reference: Data Link Connector Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

1 Did you record any DTCs in the range of U1001-U1254 with a history status?

Go to DTC U1001-U1254 Go to Step 2

2

1. Turn ON the ignition leaving the engine OFF. 2. Attempt to communicate with each module on the

class 2 serial data circuit. (If using a Tech 2, obtain this information using the class 2 Message Monitor feature.)

3. Record all of the modules communicating on the class 2 serial data circuit.

4. Compare the list of modules which are communicating to the list given.

Does any module(s) on the class 2 serial data circuit not communicate? Go to Step 3

Go to Step 13

3

Test the battery positive voltage circuits of the module that is not communicating for an open or short to ground. Refer to Control Module References in Body Control System for the applicable schematic. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9 Go to Step 4

4

1. Turn OFF the ignition. 2. Test the ground circuit(s) of the module that is not

communicating for an open or a short to ground. Refer to Control Module References in Body Control System for the applicable schematic. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition? Go to Step 9 Go to Step 5

5

1. Disconnect the star connector. 2. Inspect for poor connection at the star connector.

Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.


6

Test the class 2 serial data circuit of the module that is not communicating for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.


7

Inspect for poor connections at the battery positive voltage circuits, ignition positive voltage circuits, the ground circuits, and the class 2 serial data circuit of the module that is not communicating. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.


8

Replace the module which is not communicating. Refer to Control Module References in Body Control System for the appropriate repair instructions.

Did you complete the replacement? Go to Step 11

--

9

1. Install a scan tool. 2. Turn ON the ignition leaving the engine OFF. 3. Select the Display DTCs function for the module

which was not communicating.

Does the scan tool display any DTCs which do not begin with a "U"?

Go to Control Module References

in Body Control System for the

applicable Diagnostic System

Check Go to

Step 10

10 Use the scan tool in order to clear the DTCs.

Did you complete the action? Go to Step 11 --

11

Select the Display DTCs function for the modules which had U1000 or U1255 set as a current DTC.

Does the scan tool display DTCs which do not begin with a "U"?




Check Go to

Step 12


Did you complete the action? System OK --

13

Did you record any other DTCs for the modules which had U1000 or U1255 set as a current DTC?




Check Go to

Step 14

14

1. Install a scan tool. 2. Turn ON the ignition leaving the engine OFF. 3. Use the scan tool in order to clear the DTCs. 4. Turn OFF the ignition for at least 5 seconds. 5. Turn ON the ignition leaving the engine OFF. 6. Select the Display DTCs function.

Does the scan tool display U1000 or U1255 set as a current DTC? Go to Step 15

Go to Diagnostic

Aids

15

Important: Perform the control module programming/configuration procedure if required.

Replace to the module which had U1000 or U1255 set as a current DTC. Refer to Control Module References in Body Control System for the appropriate repair instructions.

Did you complete the replacement? System OK

--

DTC U1001-U1254

Circuit Description

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. When a module receives a message for a critical operating parameter, the module records the identification number of the module which sent the message for State of Health monitoring (Node Alive messages). A critical operating parameter is one which, when not received, requires that the module use a default value for that parameter. Once an identification number is learned by a module, it will monitor for that module's "Node Alive" message. Each module on the class 2 serial data circuit which is powered and performing functions that require detection of a communications malfunction is required to send a "Node Alive" message every 2 seconds. When no message is detected from a learned identification number for 5 seconds, a DTC U1xxx , where xxx is equal to the 3 digit identification number, is set.

The Control Module ID Number list provides a method for determining which module is not communicating. A module with an internal class 2 serial data circuit malfunction or which loses power during the current ignition cycle would have a Lost Communication DTC set by other modules. The modules that can communicate will set a DTC indicating the module that cannot communicate. When no message is detected from a learned identification number for five seconds, a DTC U1xxx, where xxx is equal to the 3 digit identification number, is set.

Control Module ID Number PCM 016

EBCM 040

BCM 064

SDM 088

IPC 096

Radio 128

When more than one Loss of Communication DTC is set in either one module or in several modules, diagnose the DTCs in the following order:

1. Current DTCs before history DTCs unless told otherwise in the diagnostic tables. 2. The DTC which is reported the most times. 3. From the lowest number DTC to the highest number DTC.


• Voltage supplied to the module is in the normal operating voltage range of 9 to 16 volts.

• Diagnostic trouble codes U1300, U1301 and U1305 do not have a current status.

• The vehicle power mode, ignition switch position, requires serial data communication to occur.


A message from a learned identification number has not been detected for the past 5 seconds.




Test Description


1. A module which loses power during an ignition cycle will cause other modules to set Lost Communication DTCs.

2. A module which loses ground during an ignition cycle will cause other modules to set Lost Communication DTCs.

3. The malfunction is due to an open in the class 2 serial data circuit or an open in the module.

7. The module which was not communicating may have set Lost Communication DTCs for those modules that it was monitoring.

9. The modules which can communicate indicate the module which cannot communicate. You must clear the DTCs from these modules to avoid future misdiagnosis.



1

Test the battery positive voltage and ignition B+ circuits of the module that is not communicating for an open or a short to ground. Refer to Control Module References in Body Control Systems for the applicable schematic. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.


2

1. Turn OFF the ignition. 2. Test the ground circuits of the module that is not

communicating for an open. Refer to Control Module References in Body Control Systems for the applicable schematic. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.


3

1. Disconnect the star connector. 2. Inspect for poor connections at the star connector.



4

Test the class 2 serial data circuit of the module that is not communicating for an open between the module and the star connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.


5

Inspect for poor connections at the battery positive voltage circuits, the ignition B+ circuits, the ground circuits , and the class 2 serial data circuit of the module that is not communicating. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.


6


Replace the module which is not communicating. Refer to Control Module References in Body Control System for the appropriate repair instructions.

Did you complete the replacement?

Go to Step 9

--

7

1. Install a scan tool 2. Turn ON the ignition leaving the engine OFF. 3. Select the Display DTCs function for the module which

was not communicating.





Check Go to Step 8


Did you complete the action? Go to Step 9 --

9

Select the Display DTCs function for the modules which had the Lost Communication with xxx DTC set.





Check

Go to Step 1

0

10

1. Use the scan tool in order to clear the DTCs. 2. Continue diagnosing or clearing the DTCs until all the

modules have been diagnosed and all the DTCs have been cleared.

Did you complete the action? System OK

--

DTC U1300, U1301, or U1305

Circuit Description

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. In addition to this, Node Alive messages are transmitted by each module on the class 2 serial data circuit about once every 2 seconds. When the module detects one of the following conditions on the class 2 serial data circuit for approximately 3 seconds, the setting of all other class 2 serial communication DTCs is inhibited and a DTC will set.

DTC Condition U1300 Low voltage on the class 2 serial data circuit.

U1301 High voltage on the class 2 serial data circuit.

U1305

Either high or low voltage on the class 2 serial data circuit.

Some modules will set DTC U1305 if they are not capable of distinguishing between a short to battery voltage or ground.

Conditions for Running the DTCs

• Voltage supplied to the module is in the normal operating voltage range.

• The vehicle power mode requires serial data communication to occur.

Conditions for Setting the DTCs

• No valid messages are detected on the class 2 serial data circuit.

• The voltage level detected on the class 2 serial data circuit is in one of the following conditions:

-

High

-

Low

• The above conditions are met for approximately 3 seconds.

Action Taken When the DTCs Sets

The module uses default values for all parameters received on the class 2 serial data circuit.




Diagnostic Aids

• These DTCs cannot be retrieved with a current status. Diagnosis of current DTCs is

accomplished via the symptom, Scan Tool Does Not Communicate with a Class 2 Device. Refer to Scan Tool Does Not Communicate with Class 2 Device .

• An intermittent condition is likely to be caused by a short on the class 2 serial data circuit. Use the Scan Tool Does Not Communicate with a Class 2 Device procedure in order to isolate an intermittent condition. Refer to Scan Tool Does Not Communicate with Class 2 Device .

Scan Tool Does Not Power Up

Circuit Description

The data link connector (DLC) is a standardized 16 cavity connector. Connector design and location is dictated by an industry wide standard, and is required to provide the following:

• Scan tool power battery positive voltage at terminal 16

• Scan tool power ground at terminal 4

• Common signal ground at terminal 5

The scan tool will power up with the ignition OFF. Some modules however, will not communicate unless the ignition is ON and the power mode master (PMM) module sends the appropriate power mode message.

Test Description

The number below refers to the step number on the diagnostic table.

4. If the battery positive voltage and ground circuits of the DLC are functioning properly. The malfunction must be due to the scan tool.


Connector End View Reference: Data Link Communications Connector End Views

1

Test the battery positive voltage circuit of the data link connector (DLC) for an open or a short to ground. Refer to Circuit Testing or Wiring Repairs in Wiring Systems.


Go to Control Module References in Body Control System for the applicable Diagnostic System Check

Go to Step 2

2

Test the ground circuit from pin 4 of the DLC for an open or high resistance. Refer to Circuit Testing or Wiring Repairs in Wiring Systems.



Go to Step 3

3

Inspect for poor connections and terminal tension at the DLC. Refer to Testing for Intermittent Conditions and Poor Connections or Connector Repairs in Wiring Systems.



Go to Step 4

4

The scan tool may be malfunctioning. Refer to the scan tool user guide.

Did you obtain a properly operating scan tool?

Go to Control Module References in Body Control System for the applicable Diagnostic System Check --

Scan Tool Does Not Communicate with Class 2 Device

Circuit Description

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. Connecting a scan tool to the DLC allows communication with the modules for diagnostic purposes. Diagnostic trouble codes (DTCs) may be set due to this symptom and during this diagnostic procedure. Complete the diagnostic procedure in order to ensure all the DTCs are diagnosed and cleared from memory.

Diagnostic Aids

• The BCM detects that the ignition is ON and sends the appropriate power mode message to

the other modules. The BCM must be connected to the class 2 serial data circuit for many other modules to communicate with the scan tool.

• If the class 2 serial data circuit was shorted to ground, U1300 or U1305 will be set as history DTCs. Refer to DTC U1300, U1301, or U1305 .

• If the class 2 serial data circuit was shorted to B+ U1301 or U1305 will be set as history DTCs. Refer to DTC U1300, U1301, or U1305 .

Test Description


2. A partial malfunction in the class 2 serial data circuit uses a different procedure from a total malfunction of the class 2 serial data circuit. The following modules communicate on the class 2 serial data circuit:


• BCM

• DIC

• EBCM

• IPC

• PCM

• Radio

• OnStar (UE1)

• SDM

3. The following DTC's may be retrieved with a history status, but are not the cause of the present condition:

• U1300

• U1301

• U1305

6. A State of Health DTC with a history status may be present along with a U1000 or U1255 having a current status. This indicates that the malfunction occurred when the ignition was ON.

7. Data link connector terminals 2 and 5 provide the connection to the class 2 serial data circuit and the signal ground circuit respectively.

9. A poor connection at the DLC terminal of the star connector would cause this condition but will not set a DTC.

10. An open in the class 2 serial data circuit between the DLC and star connector will prevent the scan tool from communicating with the modules. This condition will not set a DTC.

12. If communication cannot be established the class 2 serial data circuit may be shorted to voltage or ground. The condition may be due to the wiring or due to a malfunction in the BCM. When testing wires for a short, make sure there are no modules connected to the wires being tested.

13. The BCM detects that the ignition is ON and sends the appropriate power mode message to the other modules. Therefore, the BCM must remain connected to the DLC for the other modules to communicate with the scan tool. This test isolates the PCM class 2 serial data circuit.

31. If there are no current DTCs that begin with a "U", the communication malfunction has been repaired.

32. The communication malfunction may have prevented diagnosis of the customer complaint.



1 Does the scan tool power up?

Go to Step 2

Go to Scan Tool Does Not Power

Up

2

1. Turn ON the ignition leaving the engine OFF. 2. Attempt to communicate with each module on the

class 2 serial data circuit. If using a Tech 2, obtain this information using the Class 2 Message Monitor feature.

Does the scan tool communicate with any module on the class 2 serial data circuit? Go to Step 3 Go to Step 9

3

1. Select the Display DTCs function for each module. If using a Tech 2, use the Class 2 DTC Check feature in order to determine which modules do have DTCs set.

2. Record all of the displayed DTCs, the DTC status and the module which set the DTC.

Did you record any DTCs in the range of U1000 to U1305? Go to Step 6 Go to Diagnostic

Aids

4

Are DTC's U1300, U1301 or U1305 retrieved from any module?


5

Important: Turn ON the ignition, with the engine OFF, when testing for a short to voltage. Use the DMM MIN/MAX function to capture intermittent conditions.

Test the class 2 serial data circuit for an intermittent short to ground or an intermittent short to voltage. Refer to the following in Wiring Systems:

• Testing for Intermittent Conditions and Poor Connections

• Circuit Testing

• Connector Repairs

• Wiring Repairs



6

Is U1000 or U1255 the only DTC displayed in the previously specified range?

Go to DTC U1000 and

U1255 Go to DTC

U1001-U1254

7

1. Turn OFF the ignition. 2. Disconnect the scan tool from the data link

connector (DLC). 3. Inspect for poor connections at the DLC terminal 2

and terminal 5. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.


Go to Control Module

References in Body Control

System for the applicable Diagnostic

System Check Go to Step 8

8

Test the DLC ground circuit terminal 5 for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.






9

1. Disconnect the star connector. 2. Inspect for poor connections at the star connector.







10

Test the class 2 serial data circuit for an open or a short between the DLC terminal 2 and the DLC terminal of the star connector . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.






11

1. Connect a jumper wire to the DLC terminal of the star connector.

2. Connect the other end of the jumper wire to the BCM terminal of the star connector.

3. Turn ON the ignition leaving the engine OFF. 4. Attempt to communicate with the BCM.

Does the scan tool communicate with the BCM? Go to Step 13 Go to Step 12

12

1. Turn OFF the ignition. 2. Disconnect the BCM. 3. Test the class 2 serial data circuit between the star

connector and the BCM for a short or an open. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.


13

1. Leave the jumper wire connected to the DLC terminal and to the BCM terminal of the star connector.

2. Connect another jumper wire to the jumper wire connected to the DLC terminal of the star connector.

3. Connect the other end of the jumper wire to the PCM terminal of the star connector.

4. Turn ON the ignition leaving the engine OFF. 5. Attempt to communicate with the PCM.

Does the scan tool communicate with the PCM?


14

1. Turn OFF the ignition. 2. Disconnect the PCM. 3. Test the class 2 serial data circuit between the star

connector and the PCM for a short to ground or a short to voltage. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.


15

1. Disconnect the jumper wire from the PCM terminal of the star connector.

2. Connect the jumper wire to the auxiliary power drop connector terminal of the star connector.

3. Turn ON the ignition leaving the engine OFF. 4. Attempt to communicate with the BCM or VIU, if

equipped.

Does the scan tool communicate with the BCM? Go to Step 17 Go to Step 16

16

1. Turn OFF the ignition. 2. Disconnect the auxiliary power connector class 2

serial data circuit. 3. Test the class 2 serial data circuit between the star

connector and the auxiliary power drop connector for a short to ground or a short to voltage. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.


17

1. Disconnect the jumper wire from the auxiliary power drop connector terminal of the star connector.

2. Connect the jumper wire to the Radio terminal of the star connector.

3. Turn ON the ignition leaving the engine OFF. 4. Attempt to communicate with the Radio.

Does the scan tool communicate with the Radio? Go to Step 19 Go to Step 18

18

1. Turn OFF the ignition. 2. Disconnect the Radio. 3. Test the class 2 serial data circuit between the star

connector and the Radio for a short to ground or a short to voltage. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.



19

1. Disconnect the jumper wire from the Radio terminal of the star connector.

2. Connect the jumper wire to the EBCM terminal of the star connector.

3. Turn ON the ignition leaving the engine OFF. 4. Attempt to communicate with the EBCM.

Does the scan tool communicate with the EBCM?


20

1. Turn OFF the ignition. 2. Disconnect the EBCM. 3. Test the class 2 serial data circuit between the star

connector and the EBCM for a short to ground or a short to voltage. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.


21

1. Disconnect the jumper wire from the EBCM terminal of the star connector.

2. Connect the jumper wire to the SDM terminal of the star connector.

3. Turn ON the ignition leaving the engine OFF. 4. Attempt to communicate with the SDM. 5.

Does the scan tool communicate with the SDM? Go to Step 23 Go to Step 22

22

1. Turn OFF the ignition. 2. Disconnect SDM. 3. Test the class 2 serial data circuit between the star

connector and the SDM for a short to ground or a short to voltage. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring System.


23

1. Disconnect the jumper wire from the SDM terminal of the star connector.

2. Connect the jumper wire to the IPC terminal of the star connector.

3. Turn ON the ignition leaving the engine OFF.

Attempt to communicate with the IPC.Does the scan tool communicate with the IPC? Go to Step 25 Go to Step 24

24

1. Turn OFF the ignition. 2. Disconnect the IPC. 3. Test the class 2 serial data circuit between the star

connector and the IPC for a short to ground or a short to voltage. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.



25

1. Disconnect the jumper wire from the IPC terminal of the star connector.

2. Connect the jumper wire to the OnStar terminal of the star connector.

3. Turn ON the ignition leaving the engine OFF. 4. Attempt to communicate with OnStar, if equipped

with UE1.

Does the scan tool communicate with OnStar, if equipped with UE1? Go to Step 27 Go to Step 26

26

1. Turn OFF the ignition. 2. Disconnect the OnStar module. 3. Test the class 2 serial data circuit between the star

connector and the OnStar module for a short to ground or a short to voltage. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.


27

1. Disconnect the jumper wire from the OnStar terminal of the star connector.

2. Connect the jumper wire to the DIC terminal of the star connector.

3. Turn ON the ignition leaving the engine OFF. 4. Attempt to communicate with the DIC.

Does the scan tool communicate with the DIC? Go to Step 31 Go to Step 28

28

1. Turn OFF the ignition. 2. Disconnect the DIC. 3. Test the class 2 serial data circuit between the star

connector and the DIC for a short to ground or a short to voltage. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.


29

Inspect for poor connections at the class 2 serial data circuit of the module that is not communicating. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.


30


Replace the module which is not communicating. Refer to Control Module References in Body Control System for the appropriate repair instructions.Did you complete the replacement?

Go to Step 31

--

31

1. Reconnect all of the disconnected modules. 2. Reconnect any other disconnected connectors. 3. Install a scan tool. 4. Turn ON the ignition leaving the engine OFF. 5. Wait for 10 seconds.

The scan tool may require a power up reset before communication will occur due to a short on the class 2 serial data circuit. Turn OFF or disconnect the scan tool prior to performing this test.

6. Select the Display DTCs function for each module. If using a Tech 2, use the Class 2 DTC Check feature in order to determine which modules do have DTCs set.

7. Record all of the displayed DTCs and the DTC status.

Did you record any DTCs which begin with a "U" and with a current status? Go to Step 33 Go to Step 32

32 Did you record any DTCs which do not begin with a "U"? Go to Step 33 Go to Step 35

33

Diagnose the DTCs as directed by the diagnostic procedures for the particular module or malfunction. Refer to Control Module References in Body Control System for the applicable Diagnostic System Check.

Did you complete the action? Go to Step 34

--

34 Did you diagnose all of the DTCs? Go to Step 35 Go to Step 33


Did you complete the action? System OK --

Repair Instructions

Data Link Connector Replacement

Data Link Connector Replacement

Removal Procedure

1. Remove the screws from the data link connector. 2. Reposition the data link connector from the instrument panel.

Installation Procedure

1. Position the data link connector to the instrument panel.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

2. Install the screws to the data link connector.

Tighten Tighten the data link connector screws to 2 N·m (18 lb in).

Description and Operation

Data Link Communications Description and Operation

Data Link Communications Description and Operation

Data Link Connector (DLC)

The DLC is a standardized 16 way connector located below the instrument panel and close to the steering column. Both the connector design and location are dictated by industry wide agreement to follow SAE J1962 standards.

All DLCs are required to provide a power supply, hot at all times, to Pin 16. This circuit is used to power the scan tool. All DLCs provide a power ground at Pin 4 and a clean signal ground at Pin 5.

The class 2 serial data communications circuit is provided at Pin 2 of the DLC.

Class 2 Serial Data Link

The class 2 serial data link allows the following modules to communicate and share data with each other:


• Body Control Module (BCM)

• Digital Radio Receiver (U2K or U2L)

• Driver Information Center (DIC)

• Electronic Brake Control Module (EBCM)

• Instrument Panel Cluster (IPC)

• OnStar Module (UE1)

• Powertrain Control Module (PCM)

• Radio

• Inflatable Restraint Sensing and Diagnostic Module (SDM)

The class 2 serial data link allows a scan tool to communicate with the above modules for diagnostic and testing purposes.

Lighting Systems

Specifications Schematic and Routing Diagrams Component Locator Diagnostic Information and Procedures Repair Instructions Description and Operation

Specifications

Fastener Tightening Specifications

SPECIFICATIONS Fastener Tightening Specifications

Specification Application Metric English

Accessory Housing Switch Screws 2 N·m 18 lb in

Backup Lamp Screws 2 N·m 18 lb in

Dome Lamp Screws (SEO) 2 N·m 18 lb in

Foglamp Screws (Impala) 2 N·m 18 lb in

Foglamp Screws (Monte Carlo) 5 N·m 44 lb in

Headlamp Housing Switch Screws 2 N·m 18 lb in

High Mounted Stop Lamp Bracket 2 N·m 18 lb in

High Mounted Stop Lamp Bracket Screws 2 N·m 18 lb in

High Mounted Stop Lamp Screws 2 N·m 18 lb in

License Plate Lamp Screws 2 N·m 18 lb in

License Plate Lamp Screws (Impala) 2 N·m 18 lb in

License Plate Lamp Screws (Monte Carlo) 2 N·m 18 lb in

Rear Compartment Lamp Ground Wire Bolt/Screw 3 N·m 27 lb in

Side Rail Lamp Screws 2 N·m 18 lb in

Spotlamp Bezel Screws (SEO) 2 N·m 18 lb in

Spotlamp Bracket Clamp Bolt (SEO) 6 N·m 53 lb in

Spotlamp Bulb Screws (SEO) 2 N·m 18 lb in

Spotlamp Head Clamping Bolt (SEO) 3 N·m 27 lb in

Spotlamp Mounting Bracket Screws (SEO) 4 N·m 35 lb in

Spotlamp Wedge Key Screw (SEO) 8 N·m 71 lb in

Window Panel Lamp Bolts (SEO) 3 N·m 27 lb in


Lighting Systems Schematic Icons Headlights/Daytime Running Lights (DRL) Schematics Fog Lights Schematics Exterior Lights Schematics Interior Lights Schematics Interior Lights Dimming Schematics

Lighting Systems Schematic Icons Icon Icon Definition

Caution: When performing service on or near the SIR components or the SIR wiring, the SIR system must be disabled. Refer to SIR Disabling and Enabling . Failure to observe the correct procedure could cause deployment of the SIR components, personal injury, or unnecessary SIR system repairs.

Headlights/Daytime Running Lights (DRL) Schematics

DRL Relay, Headlamps, and Power [w/o 6J7] DRL Relay, Headlamps, and Power [w/ 6J7] Indicators, and Lamp Control

DR

L R

ela

y, H

ead

lam

ps, a

nd

Pow

er (w

/o 6

J7)

D

RL R

ela

y, F

lash

er, H

ead

lam

ps, a

nd

Pow

er (6

J7)

Ind

icato

rs, an

d L

am

p C

on

trol

Fo

g L

igh

ts Sch

em

atics

Exterior Lights Schematics

Park Lamps [Impala] Stop Lamps Control, and CHMSL [Impala] Turn/Hazard Lamps Control [Impala] Front Park, and Turn/Hazard Lamps [Impala] Rear Turn/Stop/Hazard Lamps [Impala w/o 6J7] Rear Turn/Stop/Hazard Lamps [Impala w/ 6J7] Backup Lamps [w/o 9C1/9C3/9C6] Backup Lamps [w/ 9C1/9C3/9C6]

Park

Lam

ps (Im

pala

)

Sto

p L

am

ps C

on

trol a

nd

CH

MS

L (Im

pala

)

Tu

rn/H

aza

rd L

am

ps C

on

trol (Im

pala

)

Fro

nt P

ark

, an

d T

urn

/H

aza

rd L

am

ps (Im

pala

)

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Rear T

urn

/S

top

/H

aza

rd L

am

ps (Im

pala

w/

o 6

J7)

Rear T

urn

/S

top

/H

aza

rd L

am

ps (Im

pala

w/6

J7)

Back

up

Lam

ps (w

/o 9

C1

/9

C3

/9

C6

)


Back

up

Lam

ps (9

C1

/9

C3

/9

C6

)

Interior Lights Schematics

Courtesy Lamps Control, and I/P Courtesy Lamps Control, and I/P (Late Production) Rear Compartment Roof Lighting Door Open Switches [Left] Door Open Switches [Right]

Cou

rtesy

Lam

ps C

on

trol, a

nd

I/P

(Early

Pro

du

ction

)

Cou

rtesy

Lam

ps C

on

trol, a

nd

I/P

(Late

Pro

du

ction

)

Rear C

om

partm

en

t


Roof L

igh

ting

D

oor O

pen

Sw

itches (L

eft)

Door O

pen

Sw

itches (R

igh

t)

Interior Lights Dimming Schematics

Dimming Control, and Steering Wheel Controls I/P Console, and Driver Door Fog Lamps Switch, and Front Passenger Door Class 2 Dimming

Dim

min

g C

on

trol, a

nd

Ste

erin

g W

heel C

on

trols

Con

sole

, an

d D

river D

oor

Fog

Lam

p S

witch

, an

d F

ron

t Passe

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Cla

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Component Locator

Lighting Systems Component Views Lighting Systems Connector End Views

Lighting Systems Component Views

Left Front of Impala, Right Front Similar

Lower Left Front of Vehicle

Forward of Radiator Support (9C1/9C6)

Driver A-Pillar (7X6/7X7)

Top of Instrument Panel, Ambient Light Sensor

Left Front of Instrument Panel

Turn Signal/Malfunction Switch (Impala)

Left Center of Instrument Panel

Right Front of Instrument Panel (Early Production)

Below Left Side of Instrument Panel

Lower Center of Instrument Panel

Below Center of Instrument Panel

Below Right Side of Instrument Panel

Top Center of Windshield (UE4 shown)

Right Forward Inside Roof

Inside Roof (w/9C1/9C3)

Inside Right Roof Rail, Left Similar

Package Shelf (w/6J6)

Rear Compartment, Forward of the Lid Opening

Right Front of Rear Compartment (w/T53)

Upper Right Front of Rear Compartment (9C1/9C3/9C6)

Rear Compartment Lid (w/T53)

Right Rear of Vehicle, Left Rear Similar-Impala

Top of Rear Compartment Lid

Rear Compartment Lid (Impala)

Lower Center Rear of Vehicle (Impala)

Left Front of Impala, Right Front Similar

(1) Headlamp-Left Connector

(2) Park Lamp-LF

(3) Turn Lamp-LF

(4) Headlamp-Left Low Beam

(5) Headlamp-Left

(6) Headlamp-Left High Beam

Lower Left Front of Vehicle, Lower Right Front Similar

(1) Fog Lamp-LF

(2) Fog Lamp-LF Connector

Forward of Radiator Support (9C1/9C6)

(1) Radiator Support

(2) Emergency Vehicle Headlamps Flasher (6J7)

(3) C122

(4) Emergency Vehicle Headlamps Flasher, C1 (6J7)

(5) C122

(6) Emergency Vehicle Headlamps Flasher, C2 (6J7)

Driver A-Pillar, Front Passenger A-Pillar Similar ( 7X6/7X7)

(1) Spot Lamp-Left

(2) Spot Lamp-Left Switch

(3) Spot Lamp-Left Connector

Top of Instrument Panel, Ambient Light Sensor

Left Front of Instrument Panel

(1) Instrument Panel Wiring Harness

(2) Fog Lamp Switch (T96), or Surveillance Mode Switch (9C1/9C3) Connector

(3) Fog Lamp Switch (T96), or Surveillance Mode Switch (9C1/9C3)

(4) Headlamp Switch


Turn Signal/Multifunction Switch (Impala)

(1) Turn Signal/Malfunction Switch

(2) Wiper Switch

(3) Washer Switch

(4) Cruise Control ON/OFF Switch

Left Center of Instrument Panel

Right Front of Instrument Panel (Early Production)

(1) I/P Compartment Lamp Connector

(2) I/P Compartment Door

(3) I/P Compartment Lamp

Below Left Side of Instrument Panel

(1) I/P Close-out Panel-Left

(2) I/P Courtesy Lamp-Left Bulb

(3) I/P Courtesy Lamp-Left Socket

Lower Center of Instrument Panel (w/o 9C1/9C3)

(1) G203

(2) Inflatable Restraint Steering Wheel Module Coil Connector C1

(3) Data Link Connector (DLC)

(4) C201

(5) Stop Lamp Switch Connectors

(6) Cruise Control Release Switch Connector

(7) Cruise Control Release Switch

(8) G201

Below Center of Instrument Panel

(1) Ashtray Lamp Housing

(2) Ashtray Lamp Socket

(3) Ashtray Lamp

Below Right Side of Instrument Panel

(1) I/P Courtesy Lamp-Right Socket

(2) I/P Courtesy Lamp-Right Bulb

(3) I/P Close-out Panel-Right

Top Center of Windshield

(1) Inside Rearview Mirror Connector

Right Front Inside Roof, Left Front Similar

(1) Vanity Mirror Lamp-Right Connector

(2) Vanity Mirror Lamp-Right

Inside Roof (9C1/9C3)

(1) Auxiliary Dome Lamp Ground Terminal

(2) Auxiliary Dome Lamp (6C7)

(3) Auxiliary Dome Lamp Connector

Inside Right Roof Rail, Left Similar

(1) Side Roof Rail

(2) Headliner Panel

(3) Assist Handle/Coat Hook and Courtesy/Reading Lamp-Right

Package Shelf (w/ 6J6)

(1) Emergency Vehicle Rear Window Panel Lamp-Right

(2) Emergency Vehicle Rear Window Panel Lamp-Left

(3) C306

Rear Compartment, Forward of the Lid Opening

(1) Rear Compartment Courtesy Lamp

(2) Rear Compartment Courtesy Lamp Connector

Right Front of Rear Compartment (w/ T53)

(1) C409

(2) Emergency Vehicle Rear Compartment Lid Lamps Relay

Upper Right Front of Rear Compartment (9C1/9C3/9C6)

(1) Main Body Wiring Harness

(2) C440

(3) Emergency Vehicle Rear Lamps Flasher, C1 and C2 (6J7)

(4) Emergency Vehicle Rear Lamps Flasher (6J7)

(5) Rear Window Panel Extension Brace

Under Rear Compartment Lid (T53)

(1) Emergency Vehicle Rear Compartment Lid Lamp-Left

(2) Emergency Vehicle Rear Compartment Lid Lamp-Right

(3) Emergency Vehicle Rear Compartment Lid Lamp-Right Connector

(4) Emergency Vehicle Rear Compartment Lid Lamp-Left Connector

Right Rear of Vehicle, Left Rear Similar (Impala)

(1) Tail Lamp-Right Connector

(2) Tail Lamp-Right

(3) Reflector

(4) Stop/Turn Lamp-Right

(5) Park Lamp-RR

Top of Rear Compartment Lid

(1) Center High Mounted Stop Lamp (CHMSL)

(2) Center High Mounted Stop Lamp (CHMSL) Connector

Rear Compartment Lid (Impala)

(1) P909

(2) C901

(3) Reflex

(4) Reflex

(5) Rear Lamp Applique

(6) Backup Lamp-Left

Lower Center Rear of Vehicle (Impala)

(1) License Lamp-Left Bulb and Socket

(2) License Lamp-Right Lens

(3) Rear Bumper Fascia

Lighting Systems Connector End Views

Ambient Light Sensor


• 12047662

• 2-Way F Metri-Pack 150 Series (BLK)


No. Function

A YEL/BLK 1138 DRL Ambient Light Sensor Low Reference

B LT GRN

/BLK 1137 DRL Ambient Light Sensor Signal

Ashtray Lamp


• 12124722

• Lamp Socket Wedge Base W2 (GRY)


No. Function

A GRY 8 Instrument Panel Lamp Supply Voltage

B BLK 1050 Ground

B BLK 1550 Ground (D55)

Auxiliary Dome Lamp


• 2-Way M Metri-Pack 150 (BLK) Pin Wire Color Circuit No. Function

A DK BLU/

WHT 149 Courtesy Lamp Supply Voltage

B BLK 1750 Ground

Backup Lamp-Left (Impala)


• Lamp Socket (LT GRY) Pin Wire Color Circuit No. Function

A LT GRN 24 Backup Lamp Feed

B BLK 150 Ground

Backup Lamp-Left (Monte Carlo)


• Lamp Socket Wedge Base W2 (DK GRY) Pin Wire Color Circuit No. Function


B BLK 1750 Ground

Backup Lamp-Right (Impala)


• Lamp Socket (LT GRY) Pin Wire Color Circuit No. Function


B BLK 150 Ground

Backup Lamp-Right (Monte Carlo)




B BLK 1750 Ground

Center High Mounted Stop Lamp (CHMSL)


• 2-Way F Metri-Pack 150 Series (BLK) Pin Wire Color Circuit No. Function

A WHT 17 Stop Lamp Switch Signal

B BLK 1750 Ground

Courtesy/Reading Lamp-Left



A GRY 157 Interior Lamp Control

B BLK 1750 Ground

C DK BLU/


Courtesy/Reading Lamp-Right



A GRY 157 Interior Lamp Control

B BLK 1750 Ground

C DK BLU/


Emergency Vehicle Headlamps Flasher, C1


• 12146045

• 5-Way F Metri-Pack 150 Series Sealed (NAT)


No. Function A BLK 150 Ground

B LT GRN/BLK 592 DRL Relay Control

C ORN 1340 Battery Positive Voltage

D PNK 1200 Headlamp High Beam Signal

E PNK 2322 Emergency Vehicle Headlamps Flasher Supply Voltage

Emergency Vehicle Headlamps Flasher, C2


• 5-Way M Metri-Pack 150 Series Sealed (NAT) Pin Wire Color Circuit No. Function

A -- -- Not Used

B LT GRN/BLK 592 DRL Relay Control

C -- -- Not Used

D PNK 1200 Headlamp High Beam Signal

E -- -- Not Used

Emergency Vehicle Rear Compartment Lid Lamp-Left


• 12124842

• 2-Way M Metri-Pack 150 Series (BLK)


No. Function

A TAN 2244 Left Emergency Vehicle Lid Lamp Signal

B BRN 2238 Right Emergency Vehicle Lid Lamp Signal

Emergency Vehicle Rear Compartment Lid Lamp-Right


• 12103721



No. Function

A BRN 2238 Right Emergency Vehicle Lid Lamp Signal

B -- -- Not Used

Emergency Vehicle Rear Compartment Lid Lamps Relay


• 12129715

• 6-Way F Metri-Pack 280 Series Flexlock (GRY)


No. Function A1 RED/BLK 744 Trunk Ajar Switch Signal

A2 TAN 2244 Left Emergency Vehicle Lid Lamp Signal

B1-B2 -- -- Not Used

ORN 2440 Battery Positive Voltage C1

ORN 2440 Battery Positive Voltage

C2 ORN 2440 Battery Positive Voltage

Emergency Vehicle Rear Lamps Flasher, C1


• 12047886



No. Function A WHT 17 Stop Lamp Switch Signal

B YEL 18 Left Rear Stop/Turn Lamp Supply Voltage

C DK GRN 19 Right Rear Stop/Turn Lamp Supply Voltage

D LT GRN 24 Backup Lamp Supply Voltage

E BLK 1750 Ground

F ORN 340 Battery Positive Voltage

G LT BLU 2624 Emergency Vehicle Rear Lamps Flasher Supply Voltage

H -- -- Not Used

Emergency Vehicle Rear Lamps Flasher, C2


• 12045688



No. Function A WHT 17 Stop Lamp Switch Signal


C DK GRN 19 Right Rear Stop/Turn Lamp Supply Voltage

D LT GRN 24 Backup Lamp Supply Voltage

E BLK 1750 Ground


G LT BLU 2624 Emergency Vehicle Rear Lamps Flasher Supply Voltage

H -- -- Not Used

Emergency Vehicle Rear Window Panel Lamp-Left


• 12065651



No. Function

A YEL 18 Left Rear Stop/Turn Lamp Supply Voltage

B -- -- Not Used

Emergency Vehicle Rear Window Panel Lamp-Right


• 12065651



No. Function

A DK GRN 19 Right Rear Stop/Turn Lamp Supply Voltage

B -- -- Not Used

Fog Lamp-LF



A PPL 34 Front Fog Lamps Supply Voltage

B BLK 150 Ground

Fog Lamp-RF



A PPL 34 Front Fog Lamps Supply Voltage

B BLK 150 Ground

Fog Lamp Switch


• 12089248

• 4-Way F Metri-Pack 150 Series (NAT)


No. Function A BLK/WHT 1251 Ground

B GRY 8 Instrument Panel Lamp Supply Voltage - 1

C PPL 34 Front Fog Lamps Supply Voltage

D ORN 192 Front Fog Lamp Switch Signal

Hazard Switch


• 12064769




B ORN 1240 Battery Positive Voltage

C PNK 339 Battery Positive Voltage

D -- -- Not Used

E GRY 8 Instrument Panel Lamp Supply Voltage - 1

F LT BLU 14 Left Turn Signal Lamps Supply Voltage (Impala)

F YEL 685 Left Turn Signal Lamps Supply Voltage (Monte Carlo)

G DK BLU 15 Right Turn Signal Lamps Supply Voltage (Impala)

G TAN 686 Right Turn Signal Lamps Supply Voltage (Monte Carlo)

H PPL 16 Turn Signal Flasher Signal

J BRN 27 Hazard Flasher Signal (Impala)

K WHT 17 Stop Lamp Switch Signal (Impala)

Headlamp-Left


• 12177081

• 10-Way F GT 150 Sealed (BLK)



B-C -- -- Not Used

D LT BLU 14 Left Turn Signal Lamps Supply Voltage

E YEL 32 Instrument Panel Lamp Fuse Supply Voltage - 1

F DK BLU 593 DRL Headlamp High Beam Supply Voltage

G PNK 1200 Headlamp High Beam Signal

H ORN 1340 Battery Positive Voltage

J DK BLU 1201 Headlamp Low Beam Signal

K -- -- Not Used

Headlamp-Right


• 12177081

• 10-Way F GT 150 Sealed (BLK)



B-C -- -- Not Used

D DK BLU 15 Right Turn Signal Lamps Supply Voltage

E YEL 32 Instrument Panel Lamp Fuse Supply Voltage - 1


G PNK 1200 Headlamp High Beam Signal

H ORN 1440 Battery Positive Voltage

J DK BLU 1201 Headlamp Low Beam Signal

K -- -- Not Used

Headlamp Switch


• 12129431

• 16-Way F Metri-Pack 280 ACT Series (BLK)



B-C -- -- Not Used

D YEL 10 Headlamp Switch Signal

E BLK/WHT 1251 Ground

F -- -- Not Used

G LT BLU 74 Park Lamp Switch Signal

H -- -- Not Used

J GRY 8 Instrument Panel Lamp Supply Voltage - 1

K-L -- -- Not Used

M DK BLU

/WHT 1495 Courtesy Lamp Switch Signal

N BLK/WHT 1251 Ground

P BLK 1050 Ground

R GRY 8 Instrument Panel Lamp Supply Voltage - 1

S BRN/WHT 301 Park Lamp Switch On Signal

I/P Compartment Lamp (Early Production)



A DK BLU

/WHT 148 Courtesy Lamp Supply Voltage

B BLK 1050 Ground

I/P Courtesy Lamp-Left


• 12084388

• Lamp Socket Connectors, Bulb Bases, Type W-2 (BLK)

Pin Wire Color Circuit No. Function

A DK BLU/


B WHT 156 Courtesy Lamp Low Control

I/P Courtesy Lamp-Right


• 12084388

• Lamp Socket Connectors, Bulb Bases, Type W-2 (BLK)

Pin Wire Color Circuit No. Function

A DK BLU/


B WHT 156 Courtesy Lamp Low Control

License Lamp-Left (Impala)



A BRN/WHT 301 Park Lamp Switch - Signal - On

B BLK 1750 Ground

License Lamp (Monte Carlo)




B BLK 1750 Ground

License Lamp-Right (Impala)




B BLK 1750 Ground

PRNDL Lamp


• 12162084

• Lamp Socket Components, Bulb Bases, Type W-2, Axial (LT GRY)

Pin Wire Color Circuit No. Function A GRY 8 Instrument Panel Lamp Supply Voltage

B BLK 1550 Ground

Rear Compartment Courtesy Lamp



A DK BLU

/WHT 149 Courtesy Lamp Supply Voltage

B ORN/BLK 737 Trunk Lamp Control

Spot Lamp-Left



A BLK 2710 Left Spot Lamp Supply Voltage

B -- -- Not Used

Spot Lamp-Right



A BLK 2711 Right Spot Lamp Supply Voltage

B -- -- Not Used

Stop Lamp Switch, C1


• 2-Way F Metri-Pack 480 Series (GRY) Pin Wire Color Circuit No. Function

A ORN 540 Battery Positive Voltage

B WHT 17 Stop Lamp Switch Signal

Stop Lamp Switch, C2


• 12033706

• 4-Way F Metri-Pack 280 Series (BLU)


No. Function A PNK 139 Ignition 1 Voltage

B DK GRN

/WHT 1135

A/T Shift Lock Control Solenoid Supply Voltage

C PNK 239 Ignition 1 Voltage

D PPL 420 TCC Brake Switch Signal

Surveillance Mode Switch


• 12089248




B BLK 1050 Ground

C GRY 8 Instrument Panel Lamp Supply Voltage - 1

D PPL 328 Surveillance Mode Switch Signal

Tail Lamp-Left (Impala)


• 12110293



No. Function A BRN/WHT 301 Park Lamp Switch On Signal


C BLK 1750 Ground


• 12110293



No. Function A BRN/WHT 301 Park Lamp Switch On Signal

B DK GRN 19 Right Rear Stop/Turn Lamp Supply Voltage

C BLK 1750 Ground

Tail Lamp-Right (Impala)


• 2-Way M Metri-Pack 150 Series (BLK) Pin Wire Color Circuit No. Function

A DK BLU/


B BLK 1750 Ground

Vanity Mirror Lamp-Right

Vanity Mirror Lamp-Left


• 2-Way M Metri-Pack 150 (BLK) Pin Wire Color Circuit No. Function

A DK BLU/


B BLK 1750 Ground


Diagnostic Starting Point - Lighting Systems

Diagnostic System Check - Lighting Systems

Scan Tool Output Controls

Scan Tool Data List

Scan Tool Data Definitions

Diagnostic Trouble Code (DTC) List

DTC B2532 DTC B2587 DTC B2648







Symptoms - Lighting Systems

Backup Lamps Always On

Backup Lamps Inoperative

Courtesy Lamps Always On

Courtesy Lamps Inoperative

Fog Lamp Indicator Inoperative

Fog Lamps Always On

Fog Lamps Inoperative

Hazard Lamps Always On

Hazard Lamps Inoperative

Headlamp Low or High Beams Always On

Headlamps Inoperative - High Beams

Headlamps Inoperative - Low Beams

Low and High Beams Headlamps Inoperative

Headlamps Flash to Pass Inoperative

High Beam Indicator Inoperative

Interior and Exterior Lamps Inoperative (SEO)

Interior Backlighting Does Not Dim

Interior Backlighting Inoperative

Instrument Panel Compartment Lamp Inoperative

Instrument Panel Compartment Lamp Always On

Park Lamps Always On

Park Lamps Inoperative

Reading Lamp Always On

Reading Lamp Inoperative

Rear Compartment Lamp Always On

Rear Compartment Lamp Inoperative

Inside Rearview Mirror Lamp Inoperative

Spot Lamp Inoperative

Stop Lamps Always On

Stop Lamps Inoperative

Surveillance Mode Switch Inoperative (SEO)

Turn Signal Lamps and/or Indicators Always On or Flashing

Turn Signal Lamps and/or Indicators Inoperative

Vanity Mirror Lamp Always On

Vanity Mirror Lamp Inoperative

Diagnostic Starting Point - Lighting Systems Begin the system diagnosis with the Diagnostic System Check - Lighting Systems . The Diagnostic System Check will provide the following information:

The identification of the control module(s) which command the system. The ability of the control module(s) to communicate through the serial data circuit. The identification of any stored diagnostic trouble codes (DTCs) and their status.

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.

Diagnostic System Check - Lighting Systems

Test Description


2. Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.

5. The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.

Step Action Yes No

1 Install a scan tool.

Does the scan tool power up? Go to Step 2

Go to Scan Tool Does Not Power Up in Data Link

Communications

2

1. Turn ON the ignition, with the engine OFF.

2. Attempt to establish communication with the BCM.

Does the scan tool communicate with the BCM? Go to Step 3

Go to Scan Tool Does Not Communicate with Class

2 Device in Data Link Communications

3

Important:: The engine may start during the following step. Turn OFF the engine as soon as you have observed the Crank power mode.

1. Access the Class 2 Power Mode in the Diagnostic Circuit Check on the scan tool.

2. Rotate the ignition switch through all positions while observing the ignition switch power mode parameter.

Does the ignition switch parameter reading match the ignition switch position for all switch positions? Go to Step 4

Go to Power Mode Mismatch in Body Control

System

4

Select the BCM display DTCs function on the scan tool.

Does the scan tool display any DTCs? Go to Step 5

Go to Symptoms - Lighting Systems

5

Does the scan tool display any DTCs which begin with the letter "U"?

Go to Scan Tool Does Not Communicate with Class

2 Device in Data Link Communications Go to Step 6

6 Does the scan tool display DTC B1000?

Go to Diagnostic Trouble Code (DTC) List in Body

Control System Go to Diagnostic Trouble

Code (DTC) List

Scan Tool Output ControlsScan Tool

Output Control Additional Menu

Selection(s) Description

Key Fob Button Test Output Controls The RCDLR monitors the incoming RF communications to ensure all keyless entry transmitter functions are operating properly.

Scan Tool Data ListScan Tool Parameter Data Display Units Displayed Typical Data Value

Operating Conditions: Ignition in the ON position. Bright light applied to the DRL ambient light sensor. Park brake not set. Headlamp switch in the OFF position. IP Lamp switch in the OFF position. Fog lamp switch in the OFF position. Ambient Light Sensor Data Volts 2.1 volts Ambient Light Sensor Re Outputs ON/OFF ON Backup Lamp Relay Outputs Active/Inactive Inactive Courtesy Lamp Switch Inputs Active/Inactive Inactive Dimming Switch Data Volts 0 DRL Relay Outputs Off/On On Fog Lamp Relay Outputs Off/On Off Fog Lamp Switch Inputs Active/Inactive Inactive Headlamp Relay Outputs Off/On Off Headlamp Switch Inputs Active/Inactive Inactive Hi Beam On Switch Inputs Active/Inactive Inactive Park Lamp Relay Outputs Off/On Off Park Break Switch Inputs Off/On Off Surveillance Mode Switch Inputs Inactive/Active Inactive Theater Dim 1 Ground Inputs Inactive/Active Inactive Theater Dim 2 Ground Inputs Inactive/Active Inactive Theater Dimming Outputs Off/On Off

Scan Tool Data Definitions BCM Scan Tool Data Definitions The BCM Scan Tool Data Definitions contains a brief description of all Lighting System related BCM parameters available on the scan tool. Data Ambient Light Sensor: The scan tool displays inactive or active. When the ambient light sensor detects day light conditions, the scan tool will display inactive. When the ambient light sensor detects low light conditions, the scan tool will display active. Dimming Switch: The scan tool displays 0.0 to 16.0 volts, depending on the Dimming switch position. Inputs Courtesy Lamp Switch: The scan tool displays Inactive/Active. The input of the courtesy lamp switch is displayed as Active when the courtesy lamps are on. Fog Lamp Switch: The scan tool displays Inactive/Active. The input of the fog lamp switch is displayed as active if the fog lamp switch is turned on. Headlamp Switch: The scan tool displays Inactive/Active. The input of the headlamp switch is displayed as active when the headlamps switch is On. Hi Beam On Switch: The scan tool displays Inactive/Active. The input of the high beam switch is displayed as active when the high beam headlamps are turned on. Park Brake Switch: The scan tool displays inactive or active. When the park brake is Off, the scan tool will display inactive. When the park brake is applied, the scan tool will display active. Park Lamp Switch: The scan tool displays On/Off. The input of the park lamp switch is displayed as On when the park lamps are command On. Surveillance Mode Switch: The scan tool displays Inactive/Active. The input of the emergency vehicle interior lamp switch is displayed as active if the switch is turned to the off position. Theater Dim 1 Ground: The scan tool displays Inactive/Active. The input of the theater dim 1 ground is displayed as active when the ground is present at the BCM for the theater dim lamps. Theater Dim 2 Ground: The scan tool displays Inactive/Active. The input of the theater dim 2 ground is displayed as active when the ground is present at the BCM for the theater dim lamps.

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Outputs Ambient Light Sensor Relay: The scan tool displays On/Off. This output of the BCM is displayed as On when the ambient light sensor voltage reference output is present. Backup Lamp Relay: The scan tool displays Inactive/Active. This output of the BCM is displayed as Active, if the BCM commands the backup lamps on. DRL Relay: The scan tool displays On/Off. This output of the BCM is displayed as On, if the BCM commands the DRL lamps On. Fog Lamp Relay: The scan tool displays On/Off. This output of the BCM is displayed as On, if the BCM commands the fog lamps on. Headlamp Relay: The scan tool displays On/Off. This output of the BCM is displayed as On, if the headlamps are turned on. Inadvertent Power Relay: The scan tool displays Off or On. When the BCM is not commanding the inadvertent power relay On, the scan tool will display Off. When the BCM is commanding the inadvertent power relay On, the scan tool will display On. Park Lamp Relay: The scan tool displays On/Off. This output of the BCM is displayed as On, if the BCM commands the park lamps On. Theater Dimming: The scan tool displays On/Off. This output of the BCM is displayed as On when the courtesy lamps are turned on.

Diagnostic Trouble Code (DTC) List

<- Back

DTC Diagnostic Procedure Module(s) DTC B2532 DTC B2532 Body Control Module (BCM) DTC B2533 DTC B2533 Body Control Module (BCM) DTC B2552 DTC B2552 Body Control Module (BCM) DTC B2553 DTC B2553 Body Control Module (BCM) DTC B2577 DTC B2577 Body Control Module (BCM) DTC B2578 DTC B2578 Body Control Module (BCM) DTC B2582 DTC B2582 Body Control Module (BCM) DTC B2587 DTC B2587 Body Control Module (BCM) DTC B2588 DTC B2588 Body Control Module (BCM) DTC B2602 DTC B2602 Body Control Module (BCM) DTC B2603 DTC B2603 Body Control Module (BCM) DTC B2617 DTC B2617 Body Control Module (BCM) DTC B2618 DTC B2618 Body Control Module (BCM) DTC B2647 DTC B2647 Body Control Module (BCM) DTC B2648 DTC B2648 Body Control Module (BCM) DTC B2650 DTC B2650 Body Control Module (BCM) DTC B2651 DTC B2651 Body Control Module (BCM) DTC B2654 DTC B2654 Body Control Module (BCM) DTC B2655 DTC B2655 Body Control Module (BCM) DTC B2665 DTC B2665 Body Control Module (BCM) DTC B2742 DTC B2742 Body Control Module (BCM)

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DTC B2532

Circuit Description

The body control module (BCM) controls the fog lamp relay. The BCM gets an input from the fog lamp switch circuit and then energizes the fog lamp relay by grounding the fog lamp relay coil control circuit. The BCM grounds the fog lamp relay coil control circuit if the following conditions exist:

• The ignition switch must be in the RUN position.

• The headlamp switch must be in the PARK or HEAD position.

• The headlamp dimmer switch must be in the LOW position.


The BCM must not be commanding the fog lamp relay to energize.


• The BCM detects a short to ground or open in the fog lamp relay coil control circuit when the

BCM is not trying to energize the fog lamp relay.

• The condition above must be present for more than 0.3 seconds.


The BCM stores DTC B2532 in memory.


• A current DTC B2532 will clear if the BCM no longer detects a short to ground or open in the fog lamp relay coil control circuit.

• A history DTC B2532 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.

Diagnostic Aids

• If the DTC B2532 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

• The following conditions may cause an intermittent malfunction to occur:

- An intermittent short to ground or open in fog lamp relay coil control circuit.

- The fog lamp relay coil is intermittently shorted to ground or open internally.

- The BCM is intermittently shorted to ground or open internally.

Step Action Yes No Schematic Reference: Fog Lights Schematics

1 Did you perform the Lighting System Diagnostic System Check? Go to

Step 2

Go to Diagnostic System Check - Lighting Systems

2

1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. With a scan tool, command the fog lamp relay

ON and OFF.

Does the fog lamp relay turn ON and OFF with each command?

Go to Diagnostic

Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the fog lamp relay. 3. Turn ON the ignition, with the engine OFF. 4. Probe the coil side battery positive voltage

supply circuit of the fog lamp relay with a test lamp that is connected to a good ground.

Does the test lamp illuminate? Go to Step 4 Go to Step 10

4

1. Connect a test lamp between the control circuit of the fog lamp relay and the coil side battery positive voltage supply circuit of the fog lamp relay.

2. With a scan tool, command the fog lamp relay ON and OFF .

Does the test lamp turn ON and OFF with each command?


5

Does the test lamp remain illuminated with each command?


6

Test the control circuit of the fog lamp relay for a short to voltage or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition? Go to

Step 14 Go to Step 9

7

Test the control circuit of the fog lamp relay for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



8

Inspect for poor connections at the fog lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



9

Inspect for poor connections at the harness connector of the Body Control Module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



10

Test for a open or high resistance in the coil side battery positive voltage supply circuit of the fog lamp relay. Refer to Wiring Repairs in Wiring Systems.


Step 14

Go to Step 11

11

Replace the underhood junction block. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems.

Did you complete the repairs? Go to

Step 14

--

12

Replace the fog lamp relay. Refer to Relay Replacement in Wiring Systems.


--

13

Important: Perform the set up procedure for the BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Replace the body control module. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement? Go to

Step 14

--

14

1. Use the scan tool in order to clear the DTCs . 2. Operate the vehicle within the Conditions for

Running the DTC as specified in the supporting text.

Does the DTC reset? Go to Step 2 System OK

DTC B2533

Circuit Description

The body control module (BCM) controls the fog lamp relay. The BCM gets an input from the fog lamp switch input circuit and then energizes the fog lamp relay by grounding the fog lamp relay coil control circuit. The BCM will only ground the fog lamp relay coil control circuit if the following conditions exist:


• The headlamp switch must be in the PARK or HEAD position.

• The headlamp dimmer switch must be in the LOW position.


The BCM must be commanding the fog lamp relay to energize.


• The BCM detects a short to battery in the fog lamp relay coil control circuit when the BCM

tries to energize the fog lamp relay.





• A current DTC B2533 will clear if the BCM no longer detects a short to battery in the fog lamp

relay coil control circuit.


Diagnostic Aids

• If the DTC B2533 is a history DTC, the fault may be intermittent. Refer to Testing for

Intermittent Conditions and Poor Connections in Wiring Systems.


-

An intermittent short to battery in the fog lamp relay coil control circuit.

-

The fog lamp relay coil is intermittently shorted to battery internally.

-

The BCM is intermittently shorted to battery internally.


1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check -

Lighting Systems

2

1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. With a scan tool, command the fog lamp relay ON and

OFF.

Does the fog lamp relay turn ON and OFF with each command?

Go to Diagnostic

Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the fog lamp relay. 3. Turn ON the ignition, with the engine OFF. 4. Probe the fog lamp relay coil side battery positive

voltage supply circuit a test lamp that is connected to a good ground.


4

1. Connect a test lamp between the fog lamp relay control circuit and the fog lamp relay coil side battery positive voltage supply circuit.

2. With a scan tool, command the fog lamp relay ON and OFF.

Does the test lamp turn ON and OFF with each command? Go to Step 8 Go to Step 5

5 Does the test lamp remain illuminated with each command? Go to

Step 7 Go to Step 6

6

Test the fog lamp relay control circuit for a short to voltage or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



7

Test the fog lamp relay control circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



8

Inspect for poor connections at the fog lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



9

Inspect for poor connections at the harness connector of the body control module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



10

Test for a open or high resistance in the fog lamp relay coil side battery positive volage supply circuit. Refer to Wiring Repairs in Wiring Systems.


Step 14

--

11


Did you complete the repair? Go to

Step 14

--

12



Step 14

--

13

Important: Perform the set up procedure for the body control module (BCM). Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.



Step 14

--

14

1. Use the scan tool in order to clear the DTCs. 2. Operate the vehicle within the Conditions for Running

the DTC as specified in the supporting text.


DTC B2552

Circuit Description

The body control module (BCM) controls the backup lamp relay. The BCM grounds the backup lamp relay control circuit which energizes the backup lamp relay.


Any of the following conditions may be present.

• The transaxle is not in the reverse position.

• The emergency vehicle interior lamp switch is enabled.

• The ignition switch is in the off position.


• The BCM detects a short to ground or open in the backup lamp relay control circuit when

it is not trying to energize the backup lamp relay.





• A current DTC B2552 will clear if the BCM no longer detects a short to ground or open in the

backup lamp relay control circuit.


Diagnostic Aids




-

An intermittent short to ground or open in the backup lamp control circuit.

-

The backup lamp relay coil is intermittently shorted to ground or open internally.

-

The BCM is intermittently shorted to ground or open internally.



Step 2


2

1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. With a scan tool, command the backup lamp relay

ON and OFF.

Does the backup lamp relay turn ON and OFF with each command?

Go to Diagnostic

Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the backup lamp relay. 3. Turn ON the ignition, with the engine OFF. 4. Probe the backup lamp relay coil side battery supply

voltage circuit with a test lamp that is connected to a good ground.


4

1. Connect a test lamp between the backup lamp relay coil side battery supply voltage circuit and backup lamp relay control circuit.

2. With a scan tool, command the backup lamp relay ON and OFF.


5 Does the test lamp remain illuminated with each command?


6

Test the backup lamp relay control circuit for a short to voltage or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



7

Test the backup lamp relay control circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



8

Inspect for poor connections at the backup lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



9

Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



10

Replace the I/P accessory wiring junction block - right. Refer to Instrument Panel Electrical Center or Junction Block Replacement - Right Side in Wiring Systems.


Step 13

--

11

Replace the backup lamp relay. Refer to Relay Replacement in Wiring Systems.


Step 13

--

12


Replace the BCM. Refer to Body Control Module Replacement in Body Control System.


Step 13

--

13

1. Use the scan tool in order to clear the DTCs. 2. Operate the vehicle within the Conditions for



DTC B2553

Circuit Description

The body control module (BCM) controls the backup lamp relay. The BCM grounds the backup lamps relay control circuit which energizes the backup lamp relay.


• The transaxle must be in the reverse position.


• The emergency vehicle interior lamp switch is not enabled.


• The BCM detects a short to battery in the backup lamp relay control circuit when the BCM

tries to energize the backup lamp relay.





• The BCM no longer detects a short to battery in the backup lamp relay control circuit.


Diagnostic Aids




-

An intermittent short to battery in backup lamp relay control circuit.

-

The backup lamp relay coil is intermittently shorted to the battery internally.

-

The BCM is intermittently shorted to the battery internally.

Step Action Yes No Schematic Reference: Exterior Lights Schematics

1 Did you perform the Lighting System Diagnostic System Check?

Go to Step 2


2

1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. With a scan tool, command the backup lamp relay

ON and OFF.

Does the backup lamp relay turn ON and OFF with each command?

Go to Diagnostic

Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the backup lamp relay. 3. Turn ON the ignition, with the engine OFF. 4. Using a test lamp connected to ground, probe the

backup lamp relay coil side supply circuit.


4

1. Connect a test lamp between the backup lamp relay coil side battery supply voltage circuit and the backup lamp relay control circuit.

2. With a scan tool, command the backup lamp relay ON and OFF.


5 Does the test lamp remain illuminated with each command? Go to Step 7 Go to Step 6

6

Test the backup lamp relay control circuit for a short to voltage or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



7

Test the backup lamp relay control circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



8

Inspect for poor connections at the backup lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



9




10

Replace the I/P Accessory wiring junction block - right. Refer to Instrument Panel Electrical Center or Junction Block Replacement - Right Side in Wiring Systems.


Step 13

--

11



Step 13

--

12




Step 13

--

13




DTC B2577

Circuit Description

The body control module (BCM) controls the headlamp relay. The BCM grounds the headlamp control circuit which energizes the headlamp relay.


The BCM must not be commanding the headlamp relay to energize.


• The BCM detects a short to ground or open in the headlamp relay coil control circuit when the

BCM is not trying to energize the headlamp relay.





• A current DTC B2577 will clear if the BCM no longer detect a short to ground or open in the

headlamp relay coil control circuit.


Diagnostic Aids




- An intermittent short to ground or open in the headlamp relay control circuit.

- The headlamp relay coil is intermittently shorted to ground or open internally.


Step Action Yes No Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics

1


Go to Step 2

Go to Diagnostic

System Check - Lighting Systems

2

1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. With a scan tool, command the headlamp relay ON and

OFF.

Does the headlamp relay turn ON and OFF with each command?

Go to Diagnosti

c Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the headlamp relay. 3. Turn ON the ignition, with the engine OFF. 4. Using a test lamp connected to ground, probe the

headlamp relay coil side battery positive voltage circuit.

Does the test lamp illuminate? Go to Step 4

Go to Step 10

4

1. Connect a test lamp between the headlamp relay coil side battery positive voltage circuit and the headlamp relay control circuit.

2. With a scan tool, command the headlamp relay ON and OFF.



Step 7 Go to Step 6

6

Test the headlamp relay control circuit for a short to voltage or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.


8

Inspect for poor connections at the headlamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.


Step 13 Go to

Step 11

9



Step 13 Go to

Step 12

10

Replace the LH Accessory Wiring Junction Block. Refer to Instrument Panel Electrical Center or Junction Block Replacement - Left Side in Wiring Systems.


Step 13 --

11

Replace the headlamp relay. Refer to Relay Replacement in Wiring Systems.


Step 13 --

12




Step 13 --

13

1. Use the scan tool in order to clear the DTCs. 2. Operate the vehicle within the Conditions for Running the

DTC as specified in the supporting text.


7 Test the headlamp relay control circuit for a short to ground. Go to


DTC B2578

Circuit Description

The body control module (BCM) controls the headlamp relay. The BCM grounds the headlamp relay coil control circuit, which energizes the headlamp relay.


The BCM must be commanding the headlamp relay to energize.


• The BCM detects a short to battery in the headlamp coil control circuit when the BCM tries to

energize the headlamp relay.





• A current DTC B2578 will clear if the BCM no longer detects a short to battery in the headlamp

relay coil control circuit.


Diagnostic Aids




-

An intermittent short to battery in the headlamp relay coil control circuit.

-

The headlamp relay coil is intermittently shorted to battery internally.

-




Go to Step 2


2

1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. With a scan tool, command the headlamp relay ON and

OFF.

Does the headlamp relay turn ON and OFF with each command?

Go to Diagnostic

Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the headlamp relay. 3. Turn ON the ignition, with the engine OFF. 4. Using a test lamp connected to ground, probe the

headlamp relay coil side battery positive voltage circuit.


4

1. Connect a test lamp between headlamp relay coil side battery positive circuit and the headlamp relay control circuit.

2. With a scan tool, command the headlamp relay ON and OFF.



Step 7 Go to Step 6

6

Test the headlamp relay control circuit for a short to voltage or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



7

Test the headlamp relay control circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



8

Inspect for poor connections at the headlamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



9




10

Replace the LH accessory wiring junction block. Refer to Instrument Panel Electrical Center or Junction Block Replacement - Left Side in Wiring Systems.


Step 13 --

11



Step 13 --

12




Step 13 --

13




DTC B2582

Circuit Description

The body control module (BCM) monitors the high beam signal circuit for high beam activity. When the high beam headlamps are commanded on by the DRL relay or the headlamp dimmer switch the high beam signal circuit is pulled to ground. battery positive voltage is applied to the DRL relay and the LH high beam headlamp from the DRL/EXT fuse and the RH high beam headlamp receives battery positive voltage from the EXT fuse.


The headlamps are not on and the DRL is not enabled.


• The BCM detects a short to ground or open in the high beam signal circuit . When the

headlamps are off and the DRL are off.





• A current DTC B2582 will clear when the BCM no longer detects a short to ground or an open

in the high beam signal circuit.


Diagnostic Aids




-

An intermittent short to ground in the signal circuit of the high beam indicator control.

-

An intermittent open in the signal circuit of the high beam indicator control.



Step 2


2

1. Install a scan tool. 2. Set the park brake. 3. Place a bright incandescent light over the ambient light

sensor. 4. Turn the headlamp switch to the OFF position. 5. Turn ON the ignition, with the engine OFF. 6. With a scan tool, observe the high beam ON switch

parameter in the body control module input data list.

Does the scan tool display inactive?

Go to Diagnostic

Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the DRL relay. 3. Turn ON the ignition, with the engine OFF. 4. With a scan tool observe the high beam ON switch

parameter in the body control module data list.

Does the scan tool display inactive? Go to Step 9 Go to Step 4

4

1. Turn OFF the ignition. 2. Reconnect the DRL relay. 3. Disconnect the headlamp dimmer switch at connector

C201. 4. Turn ON the ignition, with the engine OFF. 5. With a scan tool observe the high beam ON switch


Does the scan tool display inactive? Go to Step 6 Go to Step 5

5

Test the high beam signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.



6

Inspect for a poor connection at the harness connector C201. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.



7

Inspect the high beam signal circuit for a poor connection at the harness connectors of the body control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.



8

Important: perform the set up procedure for the body control module (BCM). Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.



Step 11

--

9

Replace the DRL relay. Refer to Relay Replacement in Wiring Systems.


Step 11

--

10

Replace the headlamp dimmer switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column.


Step 11

--

11




DTC B2587

Circuit Description

The body control module (BCM) controls the park lamp relay. The BCM grounds the park lamp relay coil control circuit which energizes the park lamp relay.


The BCM must not be commanding the park lamp relay to energize.


• The BCM detects a short to ground or open in the park lamp relay coil control circuit when the

BCM is not trying to energize the park lamp relay.





• A current DTC B2587 will clear if the BCM no longer detects a short to ground or open in the park lamp relay coil control circuit.


Diagnostic Aids




- An intermittent short to ground or open in the coil control circuit of the park lamp relay.

- The park lamp relay coil is intermittently shorted to ground or open internally.




Go to Step 2


2

1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. With a scan tool, command the park lamp relay

ON and OFF.

Does the park lamp relay turn ON and OFF with each command?

Go to Diagnostic

Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the park lamp relay. 3. Turn ON the ignition, with the engine OFF. 4. Using a test lamp connected to ground, probe the

park lamp relay coil side voltage circuit.


4

1. Connect a test lamp between the park lamp relay coil side voltage supply and the park lamp relay control circuit.

2. With a scan tool, command the park lamp relay ON and OFF.



6

Test the park lamp relay control circuit for a short to voltage or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



7

Test the park lamp relay control circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



8

Inspect for poor connections at the park lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



9




10

Replace the RH IP Fuse block. Refer to Instrument Panel Electrical Center or Junction Block Replacement - Right Side in Wiring Systems.


Step 13

--

11

Replace the park lamp relay. Refer to Relay Replacement in Wiring Systems.


Step 13

--

12




Step 13

--

13




DTC B2588

Circuit Description

The body control module (BCM) controls the park lamp relay. The BCM grounds the park lamp relay coil control circuit which energizes the park lamp relay.


The BCM must be commanding the park lamp relay to energize.


• The BCM detects a short to battery in the park lamp relay coil control circuit when the BCM is

trying to energize the park lamp relay.





• The BCM no longer detects a short to battery in the park lamp relay coil control circuit when

the park lamp relay is commanded to energize.


Diagnostic Aids




-

An intermittent short to battery in the park lamp relay coil control circuit.

-

The park lamp relay coil is shorted to battery internally.

-

The BCM is shorted to battery internally.


1


Go to Step 2

Go to Diagnostic


2

1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. With a scan tool, command the park lamp relay ON and

OFF.

Does the park lamp relay turn ON and OFF with each command?

Go to Diagnostic

Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the park lamp relay. 3. Turn ON the ignition, with the engine OFF. 4. Using a test lamp connected to ground, probe the park

lamp relay coil side voltage supply circuit.


4

1. Connect a test lamp between the park lamp relay coil side voltage supply and the park lamp relay control circuit.

2. With a scan tool, command the park lamp relay ON and OFF.



Step 7 Go to Step 6

6

Test the park lamp relay control circuit for a short to voltage or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



7

Test the park lamp relay control circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



8

Inspect for poor connections at the park lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



9




10

Replace the RH IP fuse block. Refer to Instrument Panel Electrical Center or Junction Block Replacement - Right Side in Wiring Systems.


Step 13

--

11



Step 13

--

12




Step 13

--

13




DTC B2602

Circuit Description

The body control module (BCM) controls the DRL relay. The BCM grounds the DRL relay coil control circuit, which energizes the DRL relay.


The BCM must not be commanding the DRL relay to energize.


• The BCM detects a short to ground or open in the DRL relay coil control circuit.





• A current DTC B2602 will clear if the BCM no longer detects a short to ground

or open in the DRL relay coil control circuit.


Diagnostic Aids



- An intermittent short to ground or open in the DRL relay coil control circuit.

- The DRL relay coil is intermittently shorted to ground or open internally.



1


Go to Step 2

Go to Diagnostic


2

1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. With a scan tool, command the DRL relay ON and

OFF.

Does the DRL relay turn ON and OFF with each command?

Go to Diagnostic

Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the DRL relay. 3. Turn ON the ignition, with the engine OFF. 4. Using a test lamp connected to ground, probe the

DRL relay coil side voltage supply circuit.


4

1. Connect a test lamp between the DRL relay coil side voltage supply and the DRL relay control circuit.

2. With a scan tool, command the DRL relay ON and OFF.



Step 7 Go to Step 6

6

Test the DRL relay control circuit for a short to voltage or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



7

Test the DRL relay control circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



8

Inspect for poor connections at the DRL relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.



9




10

Test for a high resistance or the open in the DRL relay coil side voltage supply circuit. Refer to Wiring Repairs in Wiring Systems.


Step 14

Go to Step 11

11



Step 14

--

12



Step 14

--

13




Step 14

--

14




DTC B2603

Circuit Description

The body control module (BCM) controls the DRL relay. The BCM grounds the DRL relay coil control circuit, which energizes the DRL relay.


The BCM must be commanding the DRL relay to energize.


• The BCM detects a short to battery in the DRL relay coil control circuit.





• A current DTC B2603 will clear if the BCM no longer detects a short to battery in the DRL relay

coil control circuit.


Diagnostic Aids




-

An intermittent short to battery in the DRL relay coil control circuit.

-

The DRL relay coil is intermittently shorted to battery internally.

-




Step 2


2

1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. With a scan tool, command the DRL relay ON and

OFF.

Does the DRL relay turn ON and OFF with each command?

Go to Diagnostic

Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the DRL relay. 3. Turn ON the ignition, with the engine OFF. 4. Using a test lamp connected to ground, probe the DRL

relay coil side voltage supply circuit.


4

1. Connect a test lamp between the DRL relay coil side voltage supply and the DRL relay control circuit.

2. With a scan tool, command the DRL relay ON and OFF.



Step 7 Go to Step 6

6

Test the DRL relay control circuit for a short to battery positive voltage or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.Did you find and correct the condition?

Go to


7 Test the DRL relay control circuit for a short to ground. Refer Go to


to Circuit Testing and to Wiring Repairs in Wiring Systems.


8

Inspect for poor connections at the DRL relay. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



9




10

Test for a high resistance or an open in the DRL Relay coil side voltage supply circuit. Refer to Wiring Repairs in Wiring Systems.


Step 14

--

11

Replace the underhood junction block. Refer Underhood Electrical Center or Junction Block Replacement in Wiring Systems.


Step 14

12



Step 14

--

13




Step 14

--

14




DTC B2617

Circuit Description

The body control module (BCM) controls the I/P courtesy lamps through the courtesy lamps supply voltage circuit. The BCM grounds courtesy lamps low control circuit which completes the I/P courtesy lamps ground circuit, and the lights illuminate.


The BCM must be commanding the courtesy lamps feature OFF.


• The BCM detects that the output for the courtesy lamps supply voltage circuit is low when it is

expected to be high.





• A current DTC 2617 will clear if the short to ground or open in the courtesy lamps supply

voltage circuit is no longer detected by the BCM.

• A history DTC B2617 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present nor any other malfunction in the BCM is detected.

Diagnostic Aids




-

An intermittent short to ground or open in the courtesy lamps supply voltage circuit.

-

Either I/P courtesy lamp is intermittently shorted to ground or open internally.

-


Step Action Yes No Schematic Reference: Interior Lights Dimming Schematics

1


Go to Step 2


Lighting Systems

2

1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. With a scan tool, command the light test - theater

dimming #1 output to ON and OFF.

Do the footwell lamps turn ON and OFF with each command?

Go to Diagnostic

Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the I/P courtesy lamps. 3. Turn ON the ignition, with the engine OFF. 4. Using a test lamp connected to ground, probe the

courtesy lamps supply voltage.


4

1. Connect a test lamp between the courtesy lamps supply voltage and the courtesy lamps low control circuit.

2. With a scan tool, command the light test - theater dimming #1 output ON and OFF.



6

Test the courtesy lamps low control circuit for high resistance or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.Did you find and correct the condition?


7

Test the courtesy lamps low control circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



8

Inspect for poor connections at each I/P courtesy lamp. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



9




10

Repair the high resistance or an open in the courtesy lamps supply voltage circuit of the footwell lamps. Refer to Wiring Repairs in Wiring Systems.


Step 13

--

11

Replace the inoperative I/P courtesy lamp. Refer to Instrument Panel Courtesy Lamp Bulb Replacement


Step 13

--

12




Step 13

--

13

1. Use the scan tool in order to clear the DTC. 2. Operate the vehicle within the Conditions for



DTC B2618

Circuit Description

The body control module (BCM) controls the instrument panel (I/P) courtesy lamps through the courtesy lamps supply voltage circuit. The BCM grounds the courtesy lamps low control circuit which completes the I/P courtesy lamps ground circuit, and the lights illuminate.


The BCM must command the courtesy lamps feature ON.


• The BCM detects a high when the output should be low in the courtesy lamps supply voltage

circuit.





• A current DTC B2618 will clear if the short to battery in the courtesy lamps supply voltage

circuit is no longer detected by the BCM.

• A history DTC B2618 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present and no other BCM faults are detected.

Diagnostic Aids




-

An intermittent short to battery in the courtesy lamps supply voltage circuit.

-

Either I/P courtesy lamp is intermittently shorted to battery internally.

-


Step Action Yes No Schematic Reference: Interior Lights Schematics

1


Go to Step 2

Go to Diagnostic


2

1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. With a scan tool, command the light test - theater

dimming #1 output to ON and OFF.

Do the footwell lamps turn ON and OFF with each command?

Go to Diagnostic

Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the instrument panel (I/P) courtesy lamps. 3. Turn ON the ignition, with the engine OFF. 4. Using a test lamp connected to ground, probe the

courtesy lamps supply voltage circuit.


4

1. Connect a test lamp between the courtesy lamps supply voltage and the courtesy lamps low control circuit.

2. With a scan tool, command the light test - theater dimming #1 output ON and OFF.




6 Test the courtesy lamps low control circuit for high resistance or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?


7 Test the courtesy lamps low control circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?


8

Inspect for poor connections at each I/P courtesy lamp. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



9




10

Repair the high resistance or an open in the courtesy lamps supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.


Step 13

--

11

Replace the inoperative I/P courtesy lamp. Refer to Instrument Panel Courtesy Lamp Bulb Replacement


Step 13

--

12




Step 13

--

13

1. Use the scan tool in order to clear the DTC. 2. Operate the vehicle within the Conditions for Running



DTC B2647

Circuit Description

The body control module (BCM) uses the DRL ambient light sensor to control the automatic headlamp system. The DRL ambient light sensor is connected directly to the BCM through the DRL ambient light sensor signal circuit and the DRL ambient light sensor low reference circuit.


The DRL feature or the automatic headlamp control feature must be enabled.


• The BCM detects a short to ground in the DRL ambient light sensor signal circuit.

• The ambient light sensor is internally shorted.



• The BCM stores DTC B2647 in memory.

• The SERVICE VEHICLE SOON telltale illuminates

• The headlamps, park lamps, tail lamps and marker lamps will illuminate to night intensity.


• The BCM no longer detects a short to ground in the DRL ambient light sensor

signal circuit.


Diagnostic Aids




-

An intermittent short to ground in the DRL ambient light sensor signal circuit.

-

The DRL ambient light sensor is intermittently shorted to ground internally.

-

The BCM is intermittently shorted to ground internally.

Step Action Value(s

) Yes No Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics

1


--

Go to Step 2

Go to Diagnostic


2

1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. Expose the ambient light sensor to a bright

incandescent light. 4. With a scan tool, observe the ambient light

sensor parameter in the body control module (BCM) data list.

Does the scan tool indicate that the ambient light sensor input parameter is within the specified range?

0.25 -2.5 V

Go to Diagnosti

c Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the DRL ambient light sensor. 3. Turn ON the ignition, with the engine OFF. 4. With a scan tool, observe the ambient light

sensor parameter in the body control module (BCM) data display - data list.

Does the scan tool indicate that the ambient light sensor input parameter is greater than the specified value?

5 V


4

1. Turn OFF the ignition. 2. Connect a 3 amp fused jumper wire between

the DRL ambient light sensor signal circuit and the DRL ambient light sensor low reference circuit.

3. Turn ON the ignition, with the engine OFF. 4. With a scan tool, observe the ambient light

sensor input parameter.

Does the scan tool indicate that the ambient light sensor input parameter is less than the specified value?

0.25 V


5

Test the DRL ambient light sensor signal circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.


-- Go to


6

Test the DRL ambient light sensor signal circuit for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.


--


7

Test the DRL ambient light sensor low reference circuit a high resistance or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.


-- Go to


8

Inspect for poor connections at the harness connector of the ambient light sensor. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.


--

Go to Step 12

Go to Step 10

9



--

Go to Step 12

Go to Step 11

10

Replace the DRL ambient light sensor. Refer to Daytime Running Lamp (DRL) Ambient Light Sensor Replacement .


-- Go to

Step 12

--

11




--

Go to Step 12

--

12



Does the DTC reset?

--

Go to Step 2 System OK

DTC B2648

Circuit Description

The body control module (BCM) uses the DRL ambient light sensor signal to control the automatic headlamp system. The DRL ambient light sensor is connected directly to the BCM through the DRL ambient light sensor signal circuit and the DRL ambient light low reference circuits.


The DRL feature or the automatic headlamp control feature must be enabled.


• The BCM detects that the DRL ambient light sensor signal circuit is greater than 4 volts or is

open when it is trying to enable the automatic headlamp control feature.

• The DRL ambient light sensor signal circuit is open or shorted to battery positive voltage.

• The ambient light sensor is open internally.



• The BCM stores DTC B2648 in memory

• The SERVICE VEHICLE SOON telltale illuminates

• Headlamps, park lamps, tail lamps and marker lamps illuminate to night intensity


• The BCM no longer detects the fault in the DRL ambient light sensor signal.


Diagnostic Aids




-

An intermittent open in DRL ambient light sensor signal circuit.

-

The DRL ambient light sensor is intermittently open internally.

-

The BCM is intermittently open internally.

Step Action Value(s) Yes No Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics

1


--

Go to Step 2

Go to Diagnostic


2

1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. Expose the ambient light sensor to a bright

incandescent light. 4. With a scan tool, observe the ambient light

sensor parameter in the body control module (BCM) data list.

Does the scan tool indicate that the ambient light sensor input parameter is within the specified range?

0.25 -2.5 V

Go to Diagnostic

Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the DRL ambient light sensor. 3. Turn ON the ignition, with the engine OFF.

With a scan tool, observe the DRL ambient light sensor parameter in the body control module (BCM) data display - data list. Does the scan tool indicate that the DRL ambient light sensor input parameter is greater than the specified value?

4.9 V

Go to Step 4

Go to Step 5

4

1. Turn OFF the ignition. 2. Connect a 3 amp fused jumper wire between the

DRL ambient light sensor signal circuit and the DRL ambient light sensor low reference circuit.

3. Turn ON the ignition, with the engine OFF. 4. With a scan tool, observe the DRL ambient light

sensor input parameter.

Does the scan tool indicate that the DRL ambient light sensor input parameter is less than the specified value?

0.25 V

Go to Step 8

Go to Step 6

5

Test the DRL ambient light sensor signal circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.Did you find and correct the condition?

-- Go to


6

Test the DRL ambient light sensor signal circuit for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.


-- Go to


7

Test the DRL ambient light sensor low reference circuit for a high resistance or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.


-- Go to


8

Inspect for poor connections at the harness connector of the DRL ambient light sensor. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.


--

Go to Step 12

Go to Step 10

9



--

Go to Step 12

Go to Step 11

10

Replace the DRL ambient light sensor. Refer to Daytime Running Lamp (DRL) Ambient Light Sensor Replacement Did you complete the replacement?

-- Go to

Step 12

--

11

Important: Perform the set up procedure for the BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System. Replace the body control module. Refer to Body Control Module Replacement in Body Control System.


--

Go to Step 12

--

12



Does the DTC reset?

--

Go to Step 2

System OK

DTC B2650

Circuit Description

The body control module (BCM) monitors the headlamp high beam signal circuit for high beam activity. When the high beam headlamps are commanded on by the DRL relay or the headlamp dimmer switch the headlamp high beam signal circuit is pulled to ground. Battery positive voltage is applied to the DRL relay and the LH high beam headlamp from the DRL/EXT fuse and the RH high beam headlamp receives battery positive voltage from the EXT fuse.


The headlamps are not on and the DRL is not enabled.


• The BCM detects a short to ground or open in the headlamp high beam signal circuit. When

the headlamps are off and the DRL are off.





• A current DTC B2650 will clear when the BCM no longer detects a short to ground or an open

in the headlamp high beam signal circuit.


Diagnostic Aids




-

An intermittent short to ground in the headlamp high beam signal circuit.

-

An intermittent open in the headlamp high beam signal circuit.


1


Go to Step 2

Go to Diagnostic


2

1. Install a scan tool. 2. Set the park brake. 3. Place a bright incandescent light over the ambient light

sensor. 4. Turn the headlamp switch to the OFF position. 5. Turn ON the ignition, with the engine OFF. 6. With a scan tool, observe the Hi beam On switch


Does the scan tool display active?

Go to Diagnostic

Aids Go to Step 3

3

1. Remove the LH high beam headlamp. 2. Using a test lamp connected to a known good ground,

probe the headlamp high beam signal circuit at the LH high beam headlamp harness connector.


4

1. Disconnect the RH headlamp assembly. 2. Using a test lamp connected to a known good ground,

probe the headlamp high beam signal circuit at the RH headlamp harness connector.


5

1. Using a test lamp backprobe between the DRL headlamp high beam supply voltage circuit and the headlamp high beam signal circuit at the LH headlamp harness connector.

2. Using a scan tool, command the DRL relay on.

Does the test lamp illuminate? Go to


6

1. Disconnect the headlamp assembly. 2. Using a test lamp probe between the DRL headlamp high

beam supply voltage circuit and the headlamp high beam signal circuit at the LH headlamp harness connector.



7

1. Remove the DRL relay. 2. Using a test lamp probe between battery positive voltage

and the ground circuit of the DRL relay.


8

1. Install a fused 3A jumper in the DRL relay connector between the ground circuit and the DRL headlamp high beam supply voltage circuit.

2. At the LH headlamp assembly, connect a test lamp between the DRL headlamp high beam supply voltage circuit and the headlamp high beam signal circuit.

Does the test lamp illuminate? Go to


9

Inspect for a poor connection at the harness connectors of the LH high beam headlamp. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



10

Inspect for a poor connection at the DRL Relay. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



11

Repair a poor connection or an open in the DRL headlamp high beam supply voltage circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.


Step 17 --

12

Repair a poor connection or an open in the ground circuit of the DRL Relay. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.


Step 17 --

13

Repair a poor connection or an open in the headlamp high beam signal circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to

Step 17 --

14



Step 17 --

15 Replace the LH high beam headlamp bulb.


Step 17 --

16

Replace the LH headlamp assembly. Refer to Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement .


Step 17 --

17




DTC B2651

Circuit Description

The body control module (BCM) monitors the headlamp high beam signal circuit for high beam activity. When the high beam headlamps are commanded on by the DRL relay or the headlamp dimmer switch the headlamp high beam signal circuit is pulled to ground. Battery positive voltage is applied to the DRL relay and the LH high beam headlamp from the DRL/EXT fuse and the RH high beam headlamp receives battery positive voltage from the EXT fuse.


The headlamps are not on and the DRL is enabled.


• The BCM detects a short to ground or open in the of the headlamp high beam signal circuit .

When the headlamps are off and the DRL are off.





• A current DTC B2651 will clear when the BCM no longer detects a short to ground or an open in the high beam signal circuit.


Diagnostic Aids



- An intermittent short to ground in the high beam signal circuit.

- An intermittent open in the high beam signal circuit.


1


Go to Step 2

Go to Diagnostic


2

1. Install a scan tool. 2. Place a bright incandescent light over the ambient light

sensor. 3. Turn the headlamp switch to the OFF position. 4. Turn ON the ignition, with the engine OFF. 5. With a scan tool, command the DRL relay on.

Does the LH and RH high beam headlamps illuminate?

Go to Diagnostic

Aids Go to Step 3

3

1. Remove the RH high beam headlamp. 2. Using a test lamp connected to a known good ground,

probe the battery positive voltage feed circuit at the RH high beam headlamp harness connector.


4

1. Disconnect the RH headlamp assembly. 2. Using a test lamp connected to a known good ground,

probe the battery positive voltage feed circuit at the RH headlamp harness connector.


5

1. Using a test lamp probe between battery positive voltage and the headlamp high beam signal circuit at the RH headlamp harness connector.



6

1. Disconnect the RH headlamp assembly. 2. Using a test lamp probe between battery positive voltage

and the headlamp high beam signal circuit at the RH headlamp harness connector.


Does the test lamp illuminate?

Go to Step 7

Go to Step 10

7

Inspect for a poor connection at the harness connectors of the RH high beam headlamp. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.


Step 13 Go to

Step 12

8

Inspect for a poor connection at the RH high beam headlamp. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.


Step 13 Go to

Step 11

9

Repair an open or a short to ground in the battery positive voltage feed of the RH high beam headlamp. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.


Step 13 --

10

Repair a poor connection or an open in the headlamp high beam signal circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.


Step 13 --

11 Replace the RH high beam headlamp bulb.


Step 13 --

12

Replace the RH headlamp assembly. Refer to Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement .


Step 13 --

13




DTC B2654

Circuit Description

The body control module (BCM) controls the courtesy lamps through the courtesy lamp low control circuit. The BCM grounds the courtesy lamp low control circuit which completes the interior lamps circuit, and the lamps illuminate.


The BCM must command the interior lamps output OFF.


• The BCM detects an output that is low when a high is expected in the courtesy lamp low

control circuit.





• A current DTC B2654 clears if the short to ground or open in the courtesy lamp low control

circuit is no longer detected by the BCM.

• A history DTC B2654 clears after 100 consecutive error free ignition cycles with no BCM malfunction detected.

Diagnostic Aids



-

An intermittent short to ground or open in the courtesy lamp low control circuit.

-

Any courtesy lamp is intermittently shorted to ground or open internally.

-



1


Go to Step 2

Go to Diagnostic


2

1. Turn ON the ignition, with the engine OFF. 2. With the IP dimmer switch, turn the IP lamps to full

bright then dim the IP dimmer switch to the OFF position.

Do the courtesy lamps turn to full bright then dim to OFF?

Go to Diagnostic

Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the interior lamps. 3. Turn ON the ignition, with the engine OFF. 4. Probe the courtesy lamp supply voltage circuit of the

Interior lamps circuit with a test lamp that is connected to a good ground.


4

1. Connect a test lamp between courtesy lamp supply voltage circuit and the courtesy lamp low control circuit of the interior lamp.

2. Turn the IP dimmer switch to full bright and then to OFF.

Does the test lamp turn ON then turn OFF? Go to Step 8 Go to Step 5


Step 7 Go to Step 6

6

Test the courtesy lamp low control circuit for a short to voltage or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



7

Test the courtesy lamp low control circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



8

Inspect for poor connections at each of the interior lamps. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



9




10

Repair the high resistance or an open in the courtesy lamp supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.


Step 13

--

11 Replace the defective interior lamp.


Step 13 --

12

Important: Perform the set up procedure for the body control module. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.



Step 13

--

13




DTC B2655

Circuit Description

The body control module (BCM) controls the courtesy lamps through the courtesy lamp low control circuit. The BCM grounds the courtesy lamp low control circuit which completes the courtesy lamp low control circuit, and the lamps illuminate.


The BCM must command the courtesy dimming feature ON.


• The BCM detects a short to battery in the courtesy lamp low control circuit.





• A current DTC B2655 clears if the short to battery positive voltage in the courtesy lamp low

control circuit is no longer detected by the BCM.

• A history DTC B2655 clears after 100 consecutive error free ignition cycles with no malfunction.

Diagnostic Aids



-

An intermittent short to battery in the courtesy lamp low control circuit.

-

Any courtesy lamp is intermittently shorted to battery internally.

-



1


Go to Step 2

Go to Diagnostic


2

1. Turn ON the ignition, with the engine OFF. 2. With the IP dimmer switch, turn the IP lamps to full bright

then dim the IP dimmer switch to the OFF position.

Do the lamps turn to full bright then dim to OFF?

Go to Diagnostic

Aids Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the interior lamps. 3. Turn ON the ignition, with the engine OFF. 4. Probe the courtesy lamp supply voltage circuit of the interior

lamps circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate? Go to Step 4

Go to Step 10

4

1. Connect a test lamp between courtesy lamp supply voltage circuit and the courtesy lamp low control circuit at the interior lamp.

2. Turn the IP dimmer switch to full bright and then to OFF.

Does the test lamp turn ON then turn OFF? Go to Step 8

Go to Step 5


Go to Step 7

Go to Step 6

6

Test the courtesy lamp low control circuit for a short to voltage or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.Did you find and correct the condition?

Go to


7

Test the courtesy lamp low control circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



8

Inspect for poor connections at each of the interior lamps. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.


Step 13 Go to

Step 11

9



Step 13 Go to

Step 12

10

Repair the high resistance or the open in the courtesy lamp supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.


Step 13

--

11 Replace the inoperative interior lamp.


Step 13 --

12




Step 13

--

13



Does the DTC reset? Go to Step 2

System OK

DTC B2665

Circuit Description

The headlamp switch provides a ground input into the body control module (BCM) for the park lamp switch input when the switch is activated. This input is used by the BCM to control the park lamps.


The headlamp switch must be in the PARK position.


The BCM detects a short to battery or open in the park lamp circuit when the headlamp switch is in the PARK position.




• A current DTC B2665 will clear if the BCM no longer detects a short to battery or open in the park lamp switch signal circuit.


• A scan tool may be used to clear the DTC.

Diagnostic Aids



- An intermittent short to battery or open in the park lamp switch input circuit.

- The headlamp switch is intermittently open internally.

- The BCM is intermittently shorted to battery or open internally.


1

Did you perform the Lighting System Diagnostic System Check ?

Go to Step 2

Go to Diagnostic


2

1. Install a scan tool. 2. Make sure the headlamp switch is in the off position. 3. Turn ON the ignition, with the engine OFF. 4. With a scan tool, observe the Park Lamp input

parameter in the body control module (BCM) input data list.

Does the scan tool display Inactive? Go to Step 3 Go to Step 4

3

1. Turn the headlamp switch to the park lamp position. 2. With the scan tool, observe the park lamp input

parameter.

Does the park lamp input parameter change state?

Go to Diagnostic

Aids Go to Step 4

4

1. Turn OFF the ignition. 2. Disconnect the headlamp switch. 3. Turn ON the ignition, with the engine OFF. 4. With a scan tool, observe the park lamp switch input

parameter.

Does the scan tool display Inactive? Go to Step 7 Go to Step 5

5

Test the park lamp switch signal circuit for a short to battery positive voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.


6




7

Inspect for poor connections at the harness connector of the Headlamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.


8




--

9

Replace the headlamp switch. Refer to Headlamp Switch Replacement .


--

10




DTC B2742

Circuit Description

The fog lamp switch provides a ground input into the body control module (BCM) for the fog lamp switch state input when the switch is pressed. This input is used by the BCM to control the fog lamps.


The BCM detects a short to ground in the fog lamp switch signal circuit for longer than 60 seconds.


• The BCM stores DTC B2742 in memory.

• The input and all input operations are disabled until fault is no longer detected.

Diagnostic Aids




- An intermittent short to ground in the fog lamp switch input circuit.

- The fog lamp switch is intermittently grounded internally.

- The BCM is intermittently shorted to ground internally.


1


Go to Step 2

Go to Diagnostic


2

1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. With a scan tool, observe the fog lamp switch state input

parameter in the body control module (BCM) input data list.

Does the scan tool display Inactive? Go to Step 3

Go to Step 4

3

Depress the fog lamp switch a couple of times while observing the input parameter on the scan tool.

Does the fog lamp switch state input parameter change state when it is depressed?

Go to Diagnostic

Aids Go to Step 4

4

1. Turn OFF the ignition. 2. Disconnect the fog lamp switch. 3. Turn ON the ignition, with the engine OFF. 4. With a scan tool, observe the fog lamp switch state input

parameter.

Does the scan tool display Inactive? Go to Step 7

Go to Step 5

5

Test the fog lamp switch signal circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.



6




7

Inspect for poor connections at the harness connector of the fog lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.



8




Step 10

--

9

Replace the fog lamp switch. Refer to Fog Lamp Switch Replacement .


Step 10

--

10



Does the DTC reset? Go to Step 2

System OK

Symptoms - Lighting Systems Important: The following steps must be completed before using the symptom tables.

• Perform Diagnostic System Check - Lighting Systems. • There are no DTCs set.

• The control modules can communicate via the serial data link. • Review the system operation in order to familiarize yourself with the system functions. Refer to

Exterior Lighting Systems Description and Operation and Interior Lighting Systems Description and Operation.

Visual/Physical Inspection • Inspect for aftermarket devices which could affect the operation of the lighting system. Refer to

Checking Aftermarket Accessories in Wiring Systems.

• Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Symptom List Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom: • Backup Lamps Always On

• Backup Lamps Inoperative

• Courtesy Lamps Always On

• Courtesy Lamps Inoperative

• Fog Lamp Indicator Inoperative

• Fog Lamps Always On

• Fog Lamps Inoperative

• Hazard Lamps Always On

• Hazard Lamps Inoperative

• Headlamp Low or High Beams Always On

• Headlamps Inoperative - High Beams

• Headlamps Inoperative - Low Beams

• Low and High Beams Headlamps Inoperative

• Headlamps Flash to Pass Inoperative

• High Beam Indicator Inoperative

• Interior and Exterior Lamps Inoperative (SEO)

• Interior Backlighting Does Not Dim

• Interior Backlighting Inoperative

• Interior Backlighting Does Not Dim

• Interior Backlighting Inoperative

• Instrument Panel Compartment Lamp Inoperative

• Instrument Panel Compartment Lamp Always On

• Park Lamps Always On

• Park Lamps Inoperative

• Reading Lamp Always On

• Reading Lamp Inoperative

• Rear Compartment Lamp Always On

• Rear Compartment Lamp Inoperative

• Inside Rearview Mirror Lamp Inoperative

• Spot Lamp Inoperative

• Stop Lamps Always On

• Stop Lamps Inoperative

• Surveillance Mode Switch Inoperative (SEO)

• Turn Signal Lamps and/or Indicators Always On or Flashing

• Turn Signal Lamps and/or Indicators Inoperative

• Vanity Mirror Lamp Always On

• Vanity Mirror Lamp Inoperative

Backup Lamps Always On



Go to Step 2


Lighting Systems

2

1. Turn the ignition ON. 2. Shift the gear selector lever to the DRIVE

position.

Do the backup lamps turn ON?

Go to Testing for Intermittent and Poor Connections in Wiring

Systems Go to Step 3

3 Remove the backup lamps relay.

Do the backup lamps turn OFF? Go to Step 5 Go to Step 4

4

Repair a short to battery positive voltage in the backup lamps supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair? Go to Step 6 --

5


Did you complete the replacement? Go to Step 6 --

6 Operate the system in order to verify the repair.

Did you correct the condition? System OK Go to Step 2

Backup Lamps Inoperative



Go to Step 2


Lighting Systems

2

1. Turn the ignition ON. 2. Shift the gear selector lever to the REVERSE

position.

Do the backup lamps turn ON?

Go to Testing for Intermittent and Poor Connections in

Wiring Systems Go to Step 3

3

1. Remove the backup lamps relay. 2. Connect a test lamp between the battery positive

supply voltage circuit of the switched side of the backup lamp relay and ground.


4

Connect a fused jumper across the switched side of the backup lamps relay at the RH I/P accessory wiring junction block.

Do the backup lamps turn on? Go to Step 7 Go to Step 5

5

Test for a short to ground in the backup lamps supply voltage circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.


6

Repair a high resistance or an open in the backup lamps supply voltage circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.


7



8

Replace the RH I/P fuse block. Refer to Instrument Panel Electrical Center or Junction Block Replacement -Right in Wiring Systems.




Courtesy Lamps Always On Step Action Yes No Schematic Reference: Interior Lights Dimming Schematics


Go to Step 2


Lighting Systems

2

1. Turn the headlamp switch to the OFF position. 2. Close all doors.

Are all of the courtesy lamps OFF?



3 Remove the BATT rundown protection relay.

Do the courtesy lamps turn OFF? Go to Step 6 Go to Step 4

4

1. Reinstall the BATT rundown protection relay. 2. Disconnect the RH I/P Fuse Block connector C3.

Do the courtesy lamps turn OFF? Go to Step 7 Go to Step 5

5

Repair a short to battery positive voltage on the courtesy lamps supply voltage. Refer to Wiring Repairs and to Connector Repairs in Wiring Systems.


6

Replace the BATT rundown protection relay. Refer to Relay Replacement in Wiring Systems.


7

Replace the RH I/P fuse block. Refer to Instrument Panel Electrical Center or Junction Block Replacement - Right in Wiring Systems.




Courtesy Lamps Inoperative



Go to Step 2


Lighting Systems

2

1. Turn the ignition to the ON position. 2. Open a door or turn the headlamp switch to the

DOME position.

Do the courtesy lamps turn ON?


Wiring Systems Go to Step 3 3 Are all of the courtesy lamps inoperative? Go to Step 5 Go to Step 4

4

1. Disconnect the connector C3 at the RH I/P fuse block.

2. Connect a test lamp between to the courtesy lamps supply voltage at the RH I/P fuse block and ground.


5

Repair a short to ground in the courtesy lamps supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.


6

Repair a high resistance or open in the courtesy lamps supply voltage circuit. Refer to Wiring Repairs and to Connector Repairs in Wiring Systems.


7

Replace the RH I/P fuse block. Refer to Instrument Panel Electrical Center or Junction Block Replacement - Right in Wiring Systems.




Fog Lamp Indicator Inoperative



Go to Step 2


Lighting Systems

2

1. Turn the ignition to the ON position. 2. Press the fog lamp switch to the ON position.

Are the fog lamps on and the fog lamp indicator ON?



3

1. Remove the fog lamp switch. 2. With a test lamp, backprobe between the fog

lamp supply voltage circuit and ground.


4

Repair a high resistance or an open in the fog lamp supply voltage circuit. Refer to Wiring Repairs and to Connector Repairs in Wiring Systems.


5

Replace the fog lamp switch. Refer to Fog Lamp Switch Replacement - Front .



Is the repair complete? System OK Go to Step 2

Fog Lamps Always On



Go to Step 2


Lighting Systems

2

1. Turn the ignition to the ON position. 2. Press the fog lamp switch to the OFF position.

Are the fog lamps OFF?



3 Remove the fog lamp relay.

Do the fog lamps turn OFF? Go to Step 6 Go to Step 4

4

1. Reinstall the fog lamp relay. 2. Disconnect the top underhood fuse block

connector.

Do the fog lamps turn OFF? Go to Step 7 Go to Step 5

5

Repair a short to battery positive voltage on the fog lamps supply voltage circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you complete the repair? Go to Step 8

--

6



--

7

Replace the top underhood fuse block. Refer to Underhood Electrical Center or Junction Block Replacement


--



Fog Lamps Inoperative Diagnostic Fault Information Perform the Diagnostic System Check - Lighting Systems prior to using this diagnostic procedure.

Circuit Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Fog Lamp Relay Control Circuit 2 1 1 --

Fog Lamps Supply Voltage Circuit 1 1 2 --

1. Fog Lamps Inoperative 2. Fog Lamps Always ON

Circuit/System Description When the ignition switch is in the ON position and the headlamp switch is in either PARK or HEAD position, the fog lights illuminate whenever you press the fog lamp switch. The FOG RLY fuse in the top of the engine fuse block supplies battery positive voltage to both the fog lamp relay switch contacts and to the fog lamp relay coil circuit. The fog lamp relay coil is controlled by the body control module (BCM). Whenever you press the fog lamp switch, the BCM fog lamp switch input is grounded. The BCM energizes the control circuit of the fog lamp relay coil. The current flows from the fog lamp relay to both front fog lamps and to ground G101. The fog lamps remain ON until you again press the front fog lamp switch, or until you cycle the ignition switch OFF and ON. The park lamps or low beam headlamps must be ON in order for the fog lamps to be illuminated. Fog lamp operation will be cancelled whenever the park lamps are turned OFF or the high beam headlamps have been selected. Reference Information Schematic Reference Exterior Lights Schematics Connector End View Reference Lighting Systems Connector End Views Electrical Information Reference • Circuit Testing

• Connector Repairs

• Testing for Intermittent Conditions and Poor Connections

• Wiring Repairs

Scan Tool Reference • Scan Tool Output Controls

• Scan Tool Data List

• Scan Tool Data Definitions Circuit/System Verification Ignition ON, observe the Fog Lamp Switch Input parameter while toggling the fog lamp switch ON and OFF. The reading should change between active and inactive.

Circuit/System Testing Fog Lamp switch Input parameter does not toggle between active and inactive

1. Ignition ON, observe the Fog Lamp Switch Input parameter while turning the fog lamp switch ON and OFF. The reading should change between active and inactive.

2. Test for less than 1.0 ohm of resistance between the ground circuit terminal A and ground. ⇒ If greater than the specified range, test the ground circuit for an open/high resistance or short to

voltage. 3. Connect a volt meter between the control circuit terminal D and the ground circuit terminal A. The

volt meter should display 5 volts. ⇒ If the voltmeter always displays 0 volts, test the control circuit for a short to ground or an

open/high resistance. If the circuit tests normal, replace the body control module. 4. If all circuits test normal, replace the fog lamp switch.

Fog Lamp switch Input parameter does toggle between active and inactive

1. Ignition OFF, disconnect the fog lamps relay. 2. Verify that a test lamp illuminates between the coil side B+ circuit and ground.

⇒ If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, replace the fog lamp relay.

3. Verify that a test lamp illuminates between the switch side B+ circuit and ground. ⇒ If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high

resistance. If the circuit tests normal and the B+ circuit fuse is open, test the fog lamp supply voltage circuit for a short to ground.

4. Disconnect the harness connector at the appropriate fog lamp. 5. Test for less than 1.0 ohm of resistance between the fog lamp ground circuit terminal B and ground

⇒ If greater than the specified range, test the ground circuit for an open/high resistance. 6. Connect the harness connector at the fog lamp. 7. Connect a 10A fused jumper wire between the B+ circuit and the fog lamp supply voltage circuit.

Verify the fog lamps illuminate. ⇒ If the fog lamps do not illuminate, test the control circuit for an open/high resistance. If the

circuit tests normal, replace the fog lamp bulbs. 8. Connect a test lamp between the B+ circuit and the fog lamp relay control circuit. Command the

fog lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. ⇒ If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests

normal, replace the body control module.

⇒ If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the body control module.

9. If all circuits test normal, replace the fog lamp relay. Repair Instructions • Fog Lamp Switch Replacement

• Body Control Module Replacement

Hazard Lamps Always On


1 Did you perform the Lighting System Diagnostic System Check? Go to Step 2


2

Place the hazard switch to OFF.

Do the hazard lamps remain ON continuously?

Go to Testing for Intermittent and Poor Connections in Wiring Systems Go to Step 3

3

Replace the hazard switch. Refer to Hazard Warning Switch Replacement - On Vehicle .


4

Operate the system in order to verify the repair.


Hazard Lamps Inoperative



Go to Step 2


Lighting Systems

2

1. Turn the ignition to the ON position. 2. Place the hazard lamp switch to the ON position.

Do all of the turn signal tamps flash ON and OFF?

Go to Testing for Intermittent and Poor

Connections in Wiring Systems Go to Step 3

3

1. Disconnect the hazard switch. 2. Using a test lamp connected to a known good

ground, probe the HAZ SW fuse battery positive voltage circuit.


4

Repair a high resistance, open or short to ground in the HAZ SW fuse battery positive voltage circuit. Refer to Wiring Repairs and to Connector Repairs in Wiring Systems.


5

Replace the hazard switch. Refer to Hazard Warning Switch Replacement - On Vehicle .




Headlamp Low or High Beams Always On


1


Go to Step 2

Go to Diagnostic


2

1. Turn ON the ignition, with the engine OFF. 2. Turn ON the headlamp switch. 3. Turn ON and OFF the headlamp high beam

switch. 4. Turn OFF the headlamp switch. 5. Turn OFF the ignition.

Do the headlamps operate properly?

Go to Testing for Intermittent

Conditions and Poor Connections in Wiring

Systems Go to Step 3

3

1. Turn OFF the ignition. 2. Disconnect the headlamp relay. 3. Turn ON the ignition, with the engine OFF.

Do the headlamps turn OFF? Go to Step 4 Go to Step 9

4

1. Turn OFF the ignition. 2. Reconnect the headlamp relay. 3. Disconnect the headlamp switch. 4. Turn ON the ignition, with the engine OFF.


5

1. Turn OFF the ignition. 2. Disconnect the body control module (BCM)

connector C2. 3. Turn ON the ignition with the engine OFF.


6

1. Turn OFF the ignition. 2. Disconnect the body control module (BCM)

connector C1. 3. Turn ON the ignition with the engine OFF.


7

Test the headlamp switch signal circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and repair a short to ground in the headlamp switch signal circuit? Go to Step 13 Go to Step 12

8

Test the headlamp relay control circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and repair a short to ground in the headlamp switch signal circuit? Go to Step 13 Go to Step 10

9

Repair the short to ground in the headlamp control circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.


--

10



--

11

Replace the headlamp switch. Refer to Headlamp Switch Replacement in Steering Wheel and Column.


--

12

Important: Perform the setup procedure for the body control module (BCM). Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.



--

13

Connect all components and connectors then operate the system in order to verify the repair.


Headlamps Inoperative - High Beams



Go to Step 2


Lighting Systems

2

1. Turn ON the headlamps. 2. Ensure that the headlamp dimmer switch is in the

HIGH position.

Do the high beams illuminate?



3

1. Leave the headlamp switch in the HEAD position. 2. Disconnect the headlamp dimmer switch. 3. Connect a fused jumper between the headlamp

relay supply voltage circuit of the headlamp dimmer switch and the control circuit of the headlamp relay.

Do the high beams illuminate? Go to Step 5 Go to Step 4

4

Install a fused jumper across the battery positive voltage supply circuit and the switched high beam voltage supply circuit.

Do the high beams illuminate? Go to Step 6 Go to Step 7

5

Replace the headlamp dimmer switch. Refer to Multifunction, Turn Signal Switch Replacement in Steering Wheel and Column.


6



7

Replace the LH I/P fuse block. Refer to Instrument Panel Electrical Center or Junction Block Replacement - Left in Wiring Systems.




Headlamps Inoperative - Low Beams



Go to Step 2


Lighting Systems

2

1. Turn the ignition to the ON position. 2. Turn the headlamp switch to the ON position.

Are the low beam headlamps ON?



3

1. Disconnect the headlamp dimmer switch. 2. Using a test lamp connected to a known good

ground, probe the headlamp dimmer switch low beam circuit.


4

Repair a high resistance or an open in the headlamp low beam circuit. Refer to Wiring Repairs and to Connector Repairs in Wiring Systems.


5

Replace the headlamp dimmer switch. Refer to Multifunction, Turn Signal Switch Replacement in Steering Wheel and Column.




Low and High Beams Headlamps Inoperative


1 Did you perform the Lighting Systems Diagnostic System Check?

Go to Step 2


Lighting Systems

2

1. Turn the headlamps ON. 2. Turn the headlamp dimmer switch to the LOW

BEAM position and then to the HIGH BEAM position.

Do the headlamps illuminate with each command?

Go to Testing for Intermittent Conditions and Poor


3

Connect a test lamp between the headlamp switch signal circuit and ground.


4

Repair a high resistance or an open in the headlamp switch signal circuit of the headlamp switch. Refer to Wiring Repairs or to Connector Repairs in Wiring Systems.


--

5



--



Headlamps Flash to Pass Inoperative



Go to Step 2


Lighting Systems

2

1. Turn the ignition to the ON position. 2. Turn the headlamp switch to the OFF position. 3. Place the headlamp dimmer switch in the flash to

pass position.

Do the high beam headlamps illuminated during flash to pass operation?

Go to Testing for Intermittent Conditions and Poor


3

1. Turn the headlamp switch to the HEAD position. 2. Place the headlamp dimmer switch in the high beam

position.

Are the high beam headlamps operating properly? Go to Step 4

Go to Headlamps Inoperative - High

Beams

4

Backprobe the flash to pass ground circuit of the headlamp dimmer switch at connector C201 with a test lamp that is connected to a battery voltage.


5

Inspect for poor connections at the harness connector of the headlamp dimmer switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.


6

Repair a high resistance or an open in the flash to pass ground circuit of the headlamp dimmer switch . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.


7

Replace the headlamp dimmer switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column.




Pa e 1 of 2Service Information

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High Beam Indicator Inoperative



Go to Step 2


2

1. Place the headlamp switch in the OFF position.

2. Install a scan tool. 3. Turn ON the ignition, with the

engine OFF. 4. With the scan tool, WOW the

instrument cluster. 5. Observe the high beam indicator

on the instrument cluster.

Does the high beam indicator illuminate during Instrument cluster WOW? Go to Step 3 Go to Step 7

3

1. Place the headlamp switch in the HEAD position.

2. Place the headlamp dimmer switch in the HIGH BEAM position.

3. Observe the high beam indicator.

Does the high beam indicator illuminate?

Go to Testing for Intermittent Conditions and Poor Connections in


4 Do the high beam headlamps illuminate?

Go to Step 5

Go to Headlamps Inoperative - High

Beams

5

With a scan tool go to BCM Inputs, verify the high beam ON switch parameters.

Do the parameters show the high beam switch in the ON position? Go to Step 8 Go to Step 6

6

Repair a poor connection or an open in the BCM class 2 serial data circuit. Refer to Wiring Repairs and to Connector Repairs in Wiring Systems.


7

Replace the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console.


8

Important: Perform the programing procedure for the body control module. (BCM)



9

Operate the system in order to verify the repair.


Interior and Exterior Lamps Inoperative (SEO)



Go to Step 2


Lighting Systems

2

1. Turn ON the ignition, with the engine OFF. 2. Turn the headlamp switch to the HEAD position. 3. Turn the headlamp switch to the DOME position. 4. Verify the surveillance mode switch is in the OFF

position.

Are the Headlamps and Interior lamps ON?



3 Disconnect the surveillance mode switch.

Do the Headlamps and Interior lamps turn ON? Go to Step 5 Go to Step 4

4

Test for a short to ground in the surveillance mode switch signal circuit. Refer to Measuring Frequency and to Wiring Repairs in Wiring Systems.

Did you find and repair a short to ground in the surveillance mode switch signal circuit? Go to Step 7 Go to Step 6

5

Replace the surveillance mode switch. Refer to Emergency Vehicle Interior Switch Replacement .


--

6

Important

Perform the programming procedure for the body control module (BCM).

Replace the body control module (BCM). Refer to Body Control Module Replacement in Body Control Systems.


--



Interior Backlighting Does Not Dim


1 Did you perform the Lighting System Diagnostic System Check? Go to Step 2


2

1. Turn the ignition to the ON position. 2. Turn the headlamp switch to the PARK

position. 3. Turn the I/P dimmer switch to a LOW position.

Do the I/P lamps dim?



3

1. Turn the ignition to the OFF position. 2. Turn the headlamp switch to the OFF position. 3. Turn the I/P dimmer switch to a LOW position.

Are the I/P lamps ON? Go to Step 4


Connections in Wiring Systems

4 Are the park lamps ON? Go to Park Lamps Always On Go to Step 5

5 Disconnect the headlamp switch.

Are the I/P lamps ON? Go to Step 6 Go to Step 7

6

Repair a short to battery positive voltage in the instrument panel lamp supply voltage circuit. Refer to Wiring Repairs and to Connector Repairs in Wiring Systems.


7





Interior Backlighting Inoperative



Go to Step 2


Lighting Systems

2

1. Turn the ignition switch to the RUN position. 2. Turn the door switch to the ON position. 3. Turn the headlamp switch to the HEAD position.

Do all of the interior lamps illuminate?



3 Is only one lamp inoperative? Go to Step 4 Go to Step 5

4

Repair the open or high resistance in the inoperative lamp power supply or ground circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring System.


5

Important

Perform the set up procedure for the body control module (BCM). Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.





Instrument Panel Compartment Lamp Inoperative


1 Did you perform the Lighting Systems Diagnostic System Check? Go to Step 2


2

1. Turn the ignition ON, with the engine OFF. 2. Disconnect the I/P compartment lamp and switch. 3. Connect a test lamp between the courtesy lamps supply voltage

circuit of the I/P compartment lamp and switch connector and a good ground.


3

Connect a test lamp between battery voltage and the ground circuit of the I/P compartment lamp switch connector.


4

Repair the open in the courtesy lamps supply voltage circuit of the I/P compartment lamp. Refer to Wiring Repairs in Wiring Systems.


--

5

Repair the open in the ground circuit of the I/P compartment lamp. Refer to Wiring Repairs in Wiring Systems.


--

6

Replace the I/P compartment lamp and switch. Refer to Instrument Panel (I/P) Compartment Lamp Replacement .


--


Did you correct the condition? System

OK Go to Step 2

Instrument Panel (I/P) Compartment Lamp Always On


1 Did you perform the Lighting Systems Diagnostic System Check? Go to Step 2


2 Verify that the I/P compartment door closes properly.

Does the I/P compartment door close properly? Go to Step 4 Go to Step 3

3

Adjust or repair the I/P compartment door. Refer to Striker Adjustment -Instrument Panel (I/P) Compartment in Instrument Panel, Gages and Console.


4

Replace the I/P compartment lamp and switch. Refer to Courtesy Lamp Replacement - Instrument Panel .



Did you correct the condition? System

OK Go to Step 2

Park Lamps Always OnStep Action Yes No Schematic Reference: Exterior Lights Schematics


Go to Step 2


Lighting Systems

2

Verify the reported condition , Park Lamps Always On, does exist.

Does the system operate normally?



3 Remove the park lamp relay.

Do the lamps remain ON? Go to Step 4 Go to Step 7

4 Remove the FRONT PARK LP fuse.

Do the front park lamps remain ON? Go to Step 5 Go to Step 6

5

Repair a short to battery positive voltage on the front park lamps voltage supply circuit . Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.


6

Repair a short to battery positive voltage on the rear park lamps feed circuit . Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find the short to battery positive voltage in the rear park lamps feed circuit? Go to Step 8 --

7



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Repair Instructions

Stop Lamp Switch Adjustment

Stop Lamp Switch Replacement

Headlamp Switch Replacement

Emergency Vehicle Interior Switch Replacement

Fog Lamp Switch Replacement

Hazard Warning Switch Replacement

Daytime Running Lamp (DRL) Ambient Light Sensor Replacement

Emergency Vehicle Headlamp Flasher Replacement

Emergency Vehicle Rear Flasher Replacement

Ashtray Lamp Bulb Replacement

Console Lamp Replacement

Instrument Panel Courtesy Lamp Bulb Replacement

Instrument Panel Compartment Lamp Replacement

Inside Rearview Mirror Lamp Replacement

Sunshade Illuminated Mirror Lamp Bulb Replacement

Dome Lamp Replacement (Impala and Monte Carlo)

Dome Lamp Replacement (Impala with SEO, RPO 6C7)

Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement (Impala)

Headlamp Aiming (Impala)

Front Fog Lamp Replacement (Impala)

Fog Lamp Aiming

High Mount Stop Lamp Replacement

Backup Lamp Replacement (Impala)

Rear License Plate Lamp Replacement (Impala)

Tail Lamp Replacement (Impala)

Roof Side Rail Lamp Replacement

Rear Compartment Lid Lamp Lens and Bulb Replacement (Impala RPO T53)

Spot Lamp Replacement (Impala RPO 7X6, 7X7)

Spot Lamp Bulb Replacement (Impala RPO 7X6, 7X7)

Spot Lamp Travel Adjustment (Impala RPO 7X6, 7X7)

Rear Compartment Courtesy Lamp Replacement

Stop Lamp Switch Adjustment

1. With the brake pedal in the fully released position, ensure that the stop lamp plunger is fully

depressed against the brake pedal shanks. 2. Fully insert the stop lamp switch and the cruise control switch, if equipped, into the brake

pedal bracket. 3. Push the brake pedal forward in order to set the brake push rod into the booster.

Notice: Proper stoplamp switch adjustment is essential. Improper stoplamp switch adjustment may cause brake drag, heat buildup and excessive brake lining wear.

4. Pull the brake pedal to the rear, against the internal stop. This adjusts both the stop lamp

switch and the cruise control switch. 5. Inspect the stop lamp switch for proper adjustment.

Stop Lamp Switch Replacement Removal Procedure

1. Remove the left side of the instrument panel (I/P) insulator. 2. Disconnect the electrical connector from the stop lamp switch.

3. Remove the stop lamp switch (2) from the brake pedal bracket.


1. Install the stop lamp switch (2) to the brake pedal bracket. 2. Connect the electrical connector to the stop lamp switch. 3. Install the left side of the I/P insulator. 4. Adjust the stop lamp switch. Refer to Stop Lamp Switch Adjustment .

Headlamp Switch Replacement Removal Procedure

1. Remove the instrument panel cluster trim plate bezel. Refer to Instrument Panel Cluster Trim

Plate Bezel Replacement in Instrument Panel, Gages and Console. 2. Remove the screws from the headlamp switch housing. 3. Remove the headlamp switch housing from the instrument panel. 4. Disconnect the electrical connector from the headlamp switch. 5. Disconnect the electrical connector from the foglamp switch. 6. Remove the foglamp switch from the headlamp switch housing, using a small flat bladed tool.

1. Install the foglamp switch to the headlamp switch housing, pressing into place until fully

seated. 2. Connect the electrical connector to the headlamp switch. 3. Connect the electrical connector to the foglamp switch. 4. Install the headlamp housing switch to the instrument panel.


5. Install the screws to the headlamp housing switch.

Tighten Tighten the headlamp housing switch screws to 2 N·m (18 lb in).

6. Install the instrument panel cluster trim plate bezel. Refer to Instrument Panel Cluster Trim Plate Bezel Replacement in Instrument Panel, Gages and Console.


Emergency Vehicle Interior Switch Replacement Removal Procedure

1. Remove the trim plate bezel from the instrument panel (I/P) cluster. Refer to Instrument

Panel Cluster Trim Plate Bezel Replacement in Instrument Panel, Gages, and Console. 2. Remove the headlamp switch assembly screws. 3. Pull the headlamp switch assembly from the I/P.

4. Disconnect the electrical connector from the emergency vehicle interior switch.

5. Remove the emergency vehicle interior switch from the back of the headlamp switch

assembly.


1. Install the emergency vehicle interior switch through the back of the headlamp switch

assembly by pressing the switch into place until fully seated.

2. Connect the electrical connector to the emergency vehicle interior switch.

3. Install the headlamp switch assembly to the I/P.


4. Install the headlamp switch assembly screws.

Tighten Tighten the screws to 2 N·m (18 lb in).

5. Install the trim plate bezel. Refer to Instrument Panel Cluster Trim Plate Bezel Replacement in Instrument Panel, Gages, and Console.

Fog Lamp Switch Replacement Removal Procedure

1. Remove the trim plate bezel from the instrument panel (I/P) cluster. Refer to Instrument

Panel Cluster Trim Plate Bezel Replacement in Instrument Panel, Gages, and Console. 2. Remove the headlamp switch assembly screws. 3. Pull the headlamp switch assembly from the I/P.

4. Disconnect the electrical connector from the fog lamp switch.

5. Remove the fog lamp switch from the back of the headlamp switch assembly.


1. Install the fog lamp switch through the back of the headlamp switch assembly by pressing

the switch into place until fully seated.

2. Connect the electrical connector to the fog lamp switch.

3. Install the headlamp switch assembly to the I/P.


4. Install the headlamp switch assembly screws.


5. Install the trim plate bezel. Refer to Instrument Panel Cluster Trim Plate Bezel Replacement in Instrument Panel, Gages, and Console.

Hazard Warning Switch Replacement Removal Procedure

1. Apply the parking brake. 2. Using a small, flat-bladed tool, gently remove the bezel from the ignition lock cylinder. 3. If the vehicle is equipped with a column shift, position the transaxle shift control indicator to

1. 4. Adjust the steering wheel for access.

5. For the Impala, remove the right and the left access covers from the instrument panel (I/P) fuse block.

For the Monte Carlo, remove the left access cover from the I/P fuse block.

6. Remove the steering column filler. Refer to Steering Column Opening Filler Replacement in Instrument Panel, Gages, and Console.

7. For the Monte Carlo, open the instrument panel compartment door. 8. Remove the I/P cluster trim plate screws. 9. Start at the left side of the I/P cluster trim plate. Grasp the trim plate and carefully pull

rearward. Disengage the I/P cluster trim plate in order to easily access the hazard warning switch.

10. Disconnect the electrical connector from the hazard warning switch. 11. Remove the hazard warning switch from the I/P cluster trim plate.


1. Install the hazard warning switch to the I/P cluster trim plate. 2. Connect the electrical connector to the hazard warning switch.

3. Press the I/P cluster trim plate into the I/P trim pad, until all of the retainers are fully seated.


4. Install the I/P cluster trim plate screws.


5. For the Monte Carlo, install the left access cover to the I/P fuse block.

For the Impala, install the right and the left access covers to the I/P fuse block.

6. Install the steering column filler. Refer to Steering Column Opening Filler Replacement in Instrument Panel, Gages, and Console.

7. For the Monte Carlo, close the I/P compartment door.

8. Reposition the steering wheel to the original position. 9. If the vehicle is equipped with column shift, position the transaxle shift control indicator to

Park. 10. Install the bezel to the ignition lock cylinder. 11. Release the parking brake.

Daytime Running Lamp (DRL) Ambient Light Sensor Replacement Removal Procedure

1. Remove the garnish molding from the left windshield pillar. Refer to Windshield Pillar Garnish

Molding Replacement in Interior Trim. 2. Starting at the left side, carefully lift upwards on the instrument panel (IP) upper trim panel

in order to release the retainers from the IP upper trim pad. Work towards the right in order to access the daytime running lamp (DRL) ambient light sensor.

3. Remove the DRL ambient light sensor from the IP upper trim panel by twisting the sensor 1/4 turn counterclockwise.

4. Remove the DRL ambient light sensor from the DRL ambient light sensor connector.


1. Install the daytime running lamp (DRL) ambient light sensor to the DRL ambient light sensor

connector.

2. Position the DRL ambient light sensor to the opening in the instrument panel (IP) upper trim

panel. Twist the DRL ambient light sensor 1/4 turn clockwise. 3. Verify that the DRL ambient light sensor wiring harness will not be pinched when the IP

upper trim panel is installed. Working from right to left, press down on the IP upper trim panel in order to engage the retainers to the IP upper trim pad.

4. Install the garnish molding to the left windshield pillar. Refer to Windshield Pillar Garnish Molding Replacement in Interior Trim.

Emergency Vehicle Headlamp Flasher Replacement Removal Procedure

1. Remove the upper radiator baffle. Refer to Radiator Air Upper Baffle and Deflector

Replacement . 2. Disconnect the electrical connectors. 3. Remove the headlamp flasher bolts at the front radiator support (2).

4. Remove the headlamp flasher.


1. Position the headlamp flasher (1) to the front radiator support (2).


2. Install the headlamp flasher bolts.

Tighten Tighten the bolts to 10 N·m (89 lb in).

3. Connect the electrical connectors. 4. Install the upper radiator baffle. Refer to Radiator Air Upper Baffle and Deflector

Replacement .

Emergency Vehicle Rear Flasher Replacement Removal Procedure

1. Adjust the right side rear compartment trim for access. 2. Disconnect the electrical connectors. 3. Remove the rivet from the rear window panel extension brace (1). 4. Remove the emergency vehicle rear flasher (2).


1. Position the emergency vehicle rear flasher (2) to the rear window panel extension brace (1). 2. Install a rivet to secure the flasher. 3. Connect the electrical connectors. 4. Install the rear compartment trim.

Ashtray Lamp Bulb Replacement Removal Procedure

1. Open the ashtray drawer. 2. Remove the ashtray from the drawer for accessibility. 3. Remove the ashtray lamp socket from underneath the ashtray drawer, turning

counterclockwise. 4. Remove the bulb from the socket.


1. Install the bulb to the socket. 2. Install the lamp socket to the ashtray drawer from underneath the ashtray drawer, rotating

clockwise. 3. Install the ashtray to the ashtray drawer. 4. Close the ashtray drawer.

Console Lamp Replacement Removal Procedure

1. Remove the trim plate from the front floor console. Refer to Front Floor Console Trim Plate

Replacement in Instrument Panel, Gages, and Console. 2. Rotate the socket clockwise. Pull the socket from the housing.

3. Remove the bulb from the socket.


1. Install the bulb to the socket.

2. Position the socket into the housing. Rotate the socket counterclockwise. 3. Install the trim plate into the front floor console. Refer to Front Floor Console Trim Plate

Replacement in Instrument Panel, Gages, and Console.

Instrument Panel Courtesy Lamp Bulb Replacement Removal Procedure

1. Remove the appropriate instrument panel insulator. Refer to Instrument Panel Insulator

Panel Replacement - Right Side or to Instrument Panel Insulator Panel Replacement - Left Side in Instrument Panel, Gages and Console.

2. Remove the instrument panel courtesy lamp socket, turning counterclockwise. 3. Remove the bulb from the instrument panel courtesy lamp socket.


1. Install the bulb to the instrument panel courtesy lamp socket. 2. Install the instrument panel courtesy lamp socket turning clockwise. 3. Install the instrument panel insulator. Refer to Instrument Panel Insulator Panel Replacement

- Right Side or to Instrument Panel Insulator Panel Replacement - Left Side in Instrument Panel, Gages and Console.

Instrument Panel Compartment Lamp Replacement Removal Procedure

1. Open the instrument panel compartment door. 2. Remove the instrument panel compartment lamp switch using a small flat-bladed tool, to

depress the retaining tabs. 3. Remove the compartment lamp switch from the instrument panel. 4. Disconnect the electrical connector from the instrument panel compartment lamp switch. 5. Remove the instrument panel compartment lamp switch. 6. Remove the bulb from the instrument panel lamp switch.


1. Install the bulb to the instrument panel compartment lamp switch. 2. Connect the electrical connector to the instrument panel compartment lamp switch. 3. Install the instrument panel compartment lamp switch into the opening in the instrument

panel compartment, pressing in until fully seated. 4. Close the instrument panel compartment door.

Inside Rearview Mirror Lamp Replacement Removal Procedure

1. Use a small flat-bladed tool to disengage the edge of the lamp lens closest to the windshield.

Remove the lens from the rearview mirror.

2. Carefully remove the bulb from the socket.


1. Install the bulb to the socket. 2. Align the lamp lens to the rearview mirror. Press the lens into place.

Sunshade Illuminated Mirror Lamp Bulb Replacement Removal Procedure

1. Lower the sunshade and open the illuminated mirror door. 2. Insert a small flat-bladed tool at the lower edge of the lamp lens. Carefully press down to

remove the lens.

3. Remove the bulb.


1. Install the bulb.

2. Align the upper lens tab to the opening. Insert the upper edge of the lens. 3. Insert a small flat-bladed tool at the lower edge of the lamp lens. Carefully press up to install

the lens. 4. Close the illuminated mirror door and raise the sunshade.

Dome Lamp Replacement (Impala and Monte Carlo) Removal Procedure

1. Remove the dome lamp lens from the dome lamp bezel using a small flat bladed tool as a lever on the right side of the dome lamp lens.

2. Remove the dome lamp lens from the dome lamp bezel.

3. Remove the dome lamp bulb. 4. Remove the dome lamp bezel from the headliner using a small flat bladed tool to depress the tab

retainers.

5. Remove the dome lamp from the headliner.

6. Remove the dome lamp socket from the dome lamp bezel by squeezing each terminal and pressing out.

7. Remove the dome lamp socket from the dome lamp bezel.

8. Remove the dome lamp electrical wiring from back side of the dome lamp bezel. 9. Remove the dome lamp from the vehicle.


1. Install the dome lamp socket to the dome lamp bezel by squeezing each terminal and pressing into place until fully seated.

2. Install the dome lamp electrical wiring to back side of the dome lamp bezel. Important: The dome lamp bezel will not have a tight fit to the headliner until the dome lamp lens is installed.

3. Install the dome lamp bezel to the headliner pressing into place until the tab retainers are fully seated.

4. Install the dome lamp bulb.

5. Install the dome lamp lens to the dome lamp bezel.

6. Inserting the left side of the dome lamp lens with the two retainer tabs first them pressing in the right side until fully seated.

Dome Lamp Replacement (Impala with SEO, RPO 6C7) Removal Procedure

1. Remove the (TRK/ROOF BRP) fuse before starting dome lamp removal procedures. Refer to

Power and Grounding Component Views in Wiring Systems. 2. Remove the dome lamp lens from the dome lamp bezel using a small flat bladed tool.

3. Remove the dome lamp bulb.

Important: Hold the dome lamp bezel in position when removing the screws from the dome lamp bezel. Remove the dome lamp bezel slowly to avoid loosing the dome lamp spacers.

4. Remove the screws from the dome lamp bezel.

5. Remove the dome lamp bezel from the headliner. 6. Disconnect the electrical connector if required.


1. Connect the electrical connector if required. 2. Position the done lamp spacers and wiring harness ground terminal to the dome lamp bezel

and screws.


3. Install the dome lamp bezel as an assembly to the dome lamp bracket with the dome lamp switch to the rear.

Tighten Tighten the dome lamp screws to 1.5 N·m (17 lb ft).

4. Install the dome lamp bulb.

5. Install the dome lamp lens. 6. Install the (TRK/ROOF BRP) fuse. Refer to Power and Grounding Component Views in Wiring

Systems .

Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement Impala Removal Procedure

1. Open the hood. 2. Remove the radiator air baffle. Refer to Radiator Air Baffle and Deflector Replacement - Upper in Engine

Cooling. 3. Apply light pressure to the headlamp lens to hold the headlamp in place while removing the retainers. 4. Lift up the headlamp retainers to release the headlamp from the upper fascia support. 5. Remove the headlamp from the slots in the upper fascia support.

6. Disconnect the electrical connector from the headlamp. 7. Remove the headlamp from the vehicle.

8. Remove the rubber access cover from the headlamp.

Caution: Halogen bulbs contain gas under pressure. Handling a bulb improperly could cause it to shatter into flying glass fragments. To help avoid personal injury:

9. Remove the bulb/socket from the headlamp by rotating counterclockwise.

10. Disconnect the electrical connector from the bulb/socket.

• Turn off the lamp switch and allow the bulb to cool before changing the bulb.

• Leave the lamp switch OFF until the bulb change is complete.

• Always wear eye protection when changing a halogen bulb.

• Handle the bulb only by its base. Avoid touching the glass.

• Keep dirt and moisture off the bulb.

• Properly dispose of the used bulb.

• Keep halogen bulbs out of the reach of children.


1. Connect the electrical connector to the bulb/socket.

2. Install the bulb/socket to the headlamp by rotating clockwise.

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3. Install the rubber access cover to the headlamp.

4. Connect the electrical connector to the headlamp.

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5. Position the headlamp to the upper fascia support. 6. Push the headlamp retainers down until fully seated. 7. Install the radiator air baffle. Refer to Radiator Air Baffle and Deflector Replacement - Upper in Engine Cooling. 8. Check and adjust the headlamp aim as necessary. Refer to Headlamp Aiming . 9. Close the hood.

Headlamp Aiming (Impala) Visual Aiming Preperation Procedure

Important: Some state and local laws specify requirements for headlamp aim. All of these laws must be complied with when performing any headlamp aiming operations.

Headlamp aim should be checked:

• When a new headlamp capsule is installed

• If service or repairs to the front end area have, or may have, disturbed the headlamps or their mounting

• The area will consist of a level surface large enough to allow for a vehicle and an additional 7.62 m (25 ft) measured from face of lamps to the front of the aiming screen.

• The screen will be 1.52 m (5 ft) high x 3.66 m (12 ft) wide with a matte white surface well shaded from extraneous light, and properly adjusted to the floor on which the vehicle stands. Provisions should be made to align the screen parallel with the vehicle.

• The screen shall be provided with a fixed vertical centerline, two laterally adjustable vertical tapes, and one vertically adjustable horizontal tape.

• If a regular commercial aiming screen is not available, the screen may consist of a vertical wall having a clear uninterrupted area approximately 1.83 m (6 ft) high and 3.66 m (12 ft) wide. The surface should be finished with a washable non-gloss white paint.

After the aiming screen has been set up in its permanent location, paint a reference line on the floor directly under the lens of the lamps to indicate the proper location of the headlamps when they are being aimed:

- Distance between headlamps (1)

Prior to aiming the headlamps, the following steps must be taken:

1. Remove any snow, ice or mud from the vehicle. 2. The vehicle must have a full tank of gas. 3. Stop all other work on the vehicle. 4. If any service has been performed on the vehicle, make sure that all of the components are

back in their original place. 5. The vehicle must be on a level surface.

6. The vehicle left tires must be aligned with the reference line extending from the screen with

the headlamps aligned with the reference line. 7. Do not load any cargo in the vehicle. 8. The vehicle must contain one person or 72.56 kg (160 lb) on the driver's seat. 9. Inflate the tires to the proper pressure.

10. Simulate the vehicle loads if the intended use of the vehicle is for hauling heavy loads or towing a trailer.

11. Rock the vehicle in order to stabilize the suspension. 12. Turn on the headlamps to low beam and observe the left and the top edges of the high

intensity zone on the screen. The edges of the high intensity zone should fall within the specifications.

- Center line of screen (2)

- Adjustable vertical pointer (3)

- Adjustable horizontal tape (4)

- Diagram of light screen (5)

- Vertical center line ahead of right headlamp pointer position (6)

- 7.62 m (25 ft) (7)

- Car axis (8)

- Adjustable vertical pointer

- Horizontal center line of lamps

- Vertical center line ahead of left headlamp

Headlamp Aiming Procedure

1. Open the hood.

2. Measure from the floor to the center of the headlamp bulb. 3. At the screen, measure from the floor and place the horizontal tape at the measured

distance. 4. Measure from the reference line on the floor to the left headlamp bulb centerline. 5. At the screen, measure from the reference line and place the vertical tape at the measured

distance. 6. Measure from the reference line on the floor to the right headlamp bulb centerline. 7. At the screen, measure from the reference line and place the vertical tape at the measured

distance.

Important: DO NOT cover the headlamp, this may cause excessive heat build up.

8. Turn on the low beam headlamps and block the light from projecting onto the screen from

the passenger side headlamp.

Important: Horizontal headlamp adjustment does not exist.

9. Adjust the vertical aim screw of the headlamps to the specifications required by the state and the local authorities, or as shown in step number 8.

10. Repeat the aiming procedure for the passenger side headlamp while blocking the light from projecting onto the screen from the driver side headlamp.

11. Turn the headlamps OFF. 12. Close the hood.

Front Fog Lamp Replacement (Impala) Removal Procedure

1. Remove the screw from the fog lamp. 2. Remove the fog lamp from the front bumper fascia.

3. Disconnect the electrical connector from the fog lamp bulb. 4. Remove the fog lamp bulb, turning counterclockwise.


1. Install the fog lamp bulb, turning clockwise. 2. Connect the electrical connector to the fog lamp. 3. Install the fog lamp to the front bumper fascia.


4. Install the screw to the fog lamp.


Fog Lamp Aiming The front fog lamps must be aimed for proper illumination of the road. The front fog lamp aim should be checked when a new front fog lamp assembly is installed, or if service or repairs in the front end area may have disturbed the front fog lamp mounting.

There is no horizontal adjustment for aiming the front fog lamp assemblies on this vehicle.

1. To ensure accurate vertical front fog lamp aiming, first perform the following steps to prepare the vehicle.

2. Turn the front fog lamps ON.

3. Adjust the fog lamp up or down until the top edge of the high intensity zone on the screen is

102 mm (4 in) below the horizontal centerline (2), within the range of 0 mm (0 in) (3) to 203 mm (8 in) (5), below the horizontal centerline, on the target screen.

4. Turn OFF the front fog lamps.

• Ensure that all the components are in place on the vehicle, if other service has been performed on the vehicle.

• Ensure the fuel level is full.

• Place the vehicle on a level surface 1.52 m (5 ft) away from a target screen.

• Stop all other operations of work on the vehicle.

• Jounce the vehicle to settle the suspension.

• Cover the headlamps while aiming the fog lamps.

High Mount Stop Lamp Replacement Removal Procedure

1. Open the rear compartment. 2. Remove the screw from the high mounted stoplamp bracket. 3. Remove the high mounted stoplamp bracket.

4. Remove the screws from the high mounted stoplamp. 5. Depress the retainers holding the high mounted stoplamp to the inner panel of the

compartment lid . 6. Remove the high mounted stoplamp from the rear compartment lid inner panel.

7. Disconnect the electrical connector from the high mounted stoplamp.


1. Connect the electrical connector to the high mounted stoplamp.

2. Install the high mounted stoplamp pressing in until the retainers are fully seated.


3. Install the screws to the high mounted stoplamp.

Tighten Tighten the high mounted stoplamp screws to 2 N·m (18 lb in).

4. Install the high mounted stoplamp bracket. 5. Install the screw to the high mounted stoplamp bracket.

Tighten Tighten the high mounted stoplamp bracket screw to 2 N·m (18 lb in).

6. Close the rear compartment.

Backup Lamp Replacement (Impala) Removal Procedure

1. Open the rear compartment. 2. Remove the wing nuts from the studs on the rear compartment lid applique. 3. Remove the rear compartment lid applique from the rear compartment lid. 4. Remove the backup lamp sockets from the rear compartment lid applique, turning

counterclockwise. 5. Remove the backup lamp bulbs from the sockets.


1. Install the backup lamp bulbs to the sockets. 2. Install the sockets to the backup lamp, turning clockwise. 3. Install the rear compartment lid applique to the rear compartment lid. 4. Install the wing nuts to the studs on the rear compartment lid applique and hand tighten. 5. Close the rear compartment.

Rear License Plate Lamp Replacement (Impala) Removal Procedure

1. Remove the screws from the license plate lamp. 2. Remove the license plate lamp from the rear bumper fascia. 3. Remove the license plate lamp socket, turning counterclockwise. 4. Remove the bulb from the license plate lamp socket.


1. Install the bulb to the license plate lamp socket. 2. Install the license plate lamp socket, turning clockwise. 3. Install the license plate lamp to the rear bumper fascia.


4. Install the screws to the license plate lamp.

Tighten Tighten the license plate lamp screws to 2 N·m (18 lb in).

Tail Lamp Replacement (Impala) Removal Procedure

1. Open the rear compartment. 2. Remove wingnut and pull back the rear compartment trim panel from the tail lamp. 3. Remove the wingnuts from the tail lamp. 4. Remove the tail lamp from the rear body panel.

5. Disconnect the electrical connector from the tail lamp.

6. Remove the tail lamp socket, turning counterclockwise. 7. Remove the bulb from the tail lamp socket. 8. Remove the sidemarker lamp socket, turning counterclockwise. 9. Remove the bulb from the sidemarker lamp socket.


1. Install the bulb to the tail lamp socket. 2. Install the bulb to the sidemarker lamp socket. 3. Install the sidemarker lamp socket, turning clockwise. 4. Install the tail lamp socket, turning clockwise. 5. Connect the electrical connector to the tail lamp.

6. Install the tail lamp to the rear body panel. 7. Install the wingnuts to the tail lamp. 8. Pull back the rear compartment trim panel to the tail lamp and install the wingnut. 9. Close the rear compartment.

Roof Side Rail Lamp Replacement Removal Procedure

1. Open the assist handle covers using a small flat bladed tool. 2. Remove the screws from the assist handle.

3. Remove the assist handle.

Important: The side rail lamp base plate plastic retainers might drop out. Note the location of the

retainers.

4. Remove the side rail lamp base plate. 5. Pull the service loop loose from the glue. 6. Disconnect the electrical connector from the side rail lamp.

7. Remove the side rail lamp socket from the base plate by sliding off.

8. Remove the bulb if necessary.


1. Install the bulb if necessary. 2. Install the side rail lamp socket to the base plate by sliding on.

3. Connect the electrical connector to the side rail lamp. 4. Install the service loop to glue using foam tape.

5. Align the side rail lamp base plate to the plastic retainers.

6. Position the side rail lamp assist handle to the base plate and the plastic retainers.


7. Install the screws to the side rail lamp assist handle.

Tighten Tighten the side rail lamp assist handle screws to 2 N·m (18 lb in).

8. Close the assist handle covers pressing into place until fully seated.

Rear Compartment Lid Lamp Lens and Bulb Replacement (Impala RPO T53) Removal Procedure

1. Open the rear compartment. 2. Remove the lens from the rear compartment lid lamp.

Inserted a small coin under the rear compartment lid lamp lens and then twist the coin.

3. Remove the bulb from the rear compartment lid lamp socket.


1. Install the bulb to the rear compartment lid lamp socket.

2. Install the lens to the rear compartment lid lamp, pressing into place until fully seated. 3. Close the rear compartment.

Spot Lamp Replacement (Impala RPO 7X6, 7X7) Removal Procedure

1. Remove the spot lamp wiring harness push-in retainer from the windshield garnish molding,

using a small flat bladed tool. 2. Disconnect the electrical connector.

3. Remove the spot lamp handle wedge key screw from the spot lamp handle.

Loosen the wedge key screw a few turns then with a light tap with a suitable hammer to the wedge key screw will loosen it from the spot lamp outer tube shaft.

4. Remove the spot lamp handle from the outer tube shaft. 5. Remove the rubber grommet from the outer tube shaft.

6. Loosen the spot lamp bracket set screw.

7. Pull the spot lamp with the outer tube shaft out of the spot lamp mounting bracket and set

aside. 8. Remove the spot lamp mounting bracket screws. 9. Remove the mounting bracket and the gasket from the windshield pillar.

10. Clean the mounting surface of the windshield pillar.


Important: This method of installation will stop the chance of any alignment and binding problems.

1. Install the mounting bracket and the gasket on to the spot lamp outer tube shaft. 2. Apply a small amount of RTV sealer GM P/N 12345336 or Canadian P/N 12346286 or

equivalent to the screw holes on the windshield pillar. 3. Install the mounting bracket , the gasket and the spot lamp outer tube shaft through the

windshield pillar.


4. Install the spot lamp mounting bracket screws.

Tighten Tighten the spot lamp mounting bracket screws to 3.5 N·m (31 lb in).

5. Rotate the spot lamp to the upright position.

Point the spot lamp forward.

6. Tighten the spot lamp mounting bracket set screw just enough in order to firmly hold the spot lamp in the upright position.

7. Install the rubber grommet to the outer tube shaft. 8. Install the spot lamp handle onto the outer tube shaft in the vertical down position until the

handle bottoms out, and the flat detent on the outer tube shaft is exposed through the wedge key screw hole.

9. Install the spot lamp wedge key screw.

Tighten

Tighten the spot lamp wedge key screw to 7.5 N·m (66 lb in).

10. Connect the electrical connector. 11. Install the spot lamp wiring harness push-in retainer to the windshield garnish molding,

pressing in until fully seated. 12. Inspect the spot lamp for proper operation.

13. If spot lamp adjustment and/or electrical diagnosis are required, refer to the following procedures.

• The handle must rotate the spotlamp approximately 90 degrees about the spot lamp shaft axis from the parked position to the vertical position.

• The spot lamp head must rotate 360 degrees about its axis.

• The spot lamp must able to be turned ON/OFF independent of the ignition switch.

• For spot lamp travel adjustment, refer to Spot Lamp Travel Adjustment .

• For electrical diagnosis, refer to Power Distribution Schematics .

Spot Lamp Bulb Replacement (Impala RPO 7X6, 7X7) Removal Procedure

1. Remove the spot lamp wiring harness push-in retainer from the windshield garnish molding,

using a small flat bladed tool. 2. Disconnect the electrical connector.

3. Remove the screw from the spot lamp bezel.

4. Remove the spot lamp bezel from the spot lamp.

5. Remove the lamp from the spot lamp.

6. Remove spot lamp bulb retaining clip.

7. Remove the spot lamp bulb from the spot lamp.

8. Disconnect the spot lamp bulb electrical connector.


1. Connect the spot lamp bulb electrical connector.

2. Install the spot lamp bulb to the spot lamp.

3. Install the spot lamp bulb retaining clip.

Important: The spot lamp assembly must be clocked in the UP position, refer to the emblem on the face of the lamp.

4. Holding the spot lamp in position, install the spot lamp bezel to the spot lamp.


5. Install the spot lamp bezel screws.

Tighten Tighten the spot lamp bezel screws to 2 N·m (18 lb in).

6. Using a small flat-bladed tool, install the spot lamp wiring harness push-in retainer to the

windshield garnish molding. 7. Connect the electrical connector. 8. Inspect the spot lamp for proper operation.

Spot Lamp Travel Adjustment (Impala RPO 7X6, 7X7)

1. Loosen the spot lamp bracket clamp bolt. 2. Grasp the spot lamp.

Slowly rotate the spot lamp inboard until the shaft contacts the parkstop position.

3. Rotate the spot lamp slowly outboard to 5 degrees past the vertical position in order for the backstop to be in motion and the outer tube shaft to rotate.

4. Tighten the bracket clamp bolt sufficiently, in order to prevent the outer shaft tube from rotating while the spotlamp is moving between the stop positions.

5. Rotate the spot lamp head inboard to the parkstop position in order to prevent the spot lamp from coming in contact with the body components.

6. Position the parkstop of the shaft in order to rotate the spot lamp on its axis, clearing the nearest body components by 13-0.5 mm (0.50-0.02 in).


7. Tighten the bracket clamp screw when the parkstop has been set, in order to prevent rotation of the spot lamp shaft.

Tighten Tighten the spot lamp bracket clamp bolt to 6 N·m (53 lb in).

8. Adjust the spot lamp head clamping bolt, in order to easily rotate the spot lamp (120

degrees) in any adjustable position between the parkstop and the backstop positions.

The total motion of the spot lamp is approximately 90 degrees.

Tighten Tighten the spot lamp head clamping bolt to 2.5 N·m (22 lb in).

Rear Compartment Courtesy Lamp Replacement Removal Procedure

1. Open the rear compartment. 2. Remove the rear compartment lamp using a small flat-bladed tool to release the retaining

tabs. 3. Remove the bulb from the rear compartment lamp socket.


1. Install the bulb to the rear compartment lamp socket. 2. Install the rear compartment lamp, pressing into place until full seated. 3. Close the rear compartment.


Exterior Lighting Systems Description and Operation Interior Lighting Systems Description and Operation

Exterior Lighting Systems Description and Operation

Exterior Lamps

The exterior lighting consist of the following lamps:

• The Headlamps

• The Daytime Running Lamps (DRL)

• The Fog Lamps

• The Park, Tail, Licence and Marker Lamps

• The Turn Signal Lamps

• The Stop Lamps

• Special Equipment Option (SEO) Lighting

• The Backup Lamps

Headlamps

You can use the headlamps in two different ways.

• Place the headlamp switch in the ON position for normal operation.

• Place the headlamp switch in the OFF position for automatic lamp control (ALC). During ALC the high beam headlamps are On at reduced intensity for daytime running lamp (DRL) operation in daylight conditions, or low beam headlamps On in low light conditions.

The DRL/EXT LTS fuse and the EXT lamps fuse in the underhood junction block supply battery positive voltage at all times to both of low beam lamps and to the right high beam lamp. The low beam circuit continues to the high/low beam switch, then, depending on the position of the dimmer switch, connects to the normally-open headlamp relay switch contacts. Placing the headlamp switch in the HEAD position provides a ground path for the headlamp switch input of the Body Control Module (BCM). After receiving this input, the BCM energizes the headlamp relay. When the headlamp relay is energized, the low beam circuit is connected to ground G201. The high beam circuit is divided into a left and a right side circuit.

The DRL/EXT LTS fuse in the underhood ignition block supplies battery positive voltage to both the coil and to the normally-closed contact of the DRL relay switch circuit. During high beam operation, the left side current flow is through the closed contacts of the DRL relay, and to the left high beam lamp.

The EXT Lamps fuse in the top of the engine fuse block supplies battery positive voltage to the right high beam lamp. Both high beam circuits are then connected together, and continue to the dimmer switch. When the driver closes the high beam contacts of the dimmer switch, the circuit is grounded at G201.

Both the headlight switch and the BCM provide a ground, or control circuit, to the headlight relay coil circuit for manual or automatic headlamp operation. When you place the headlamp switch in the OFF position, and the ambient light sensor indicates low light conditions, the BCM energizes the headlamp relay for low beam operation. You may switch the headlights to high beam by pulling the dimmer switch handle toward you until the dimmer switch is activated. When the dimmer switch is placed in the HIGH position, the indicator lamp input to the BCM is pulled low. The BCM then sends a class 2 message to the instrument cluster in order to illuminate the high beam indicator lamp.

If the headlamp switch is left in the head position, the inadvertent power control feature will turn off the headlights 10 minutes after you turn the ignition switch to the OFF position. If you place the headlamp switch in the head position after the ignition switch has been turned OFF, or if the ignition switch is in the ACCY position, the headlights will remain ON until you turn them OFF or until the battery runs dead.

FTP

With the headlamps in the low beam position, you may momentarily turn ON or flash the high beams using the dimmer switch handle. When you pull the headlamp dimmer switch handle toward you, the flash-to-pass (FTP) switch closes, grounding the high beam circuit at G201. Both high beams will remain ON until you release the switch handle. If the low beam headlamps were ON during an FTP operation, the headlamps will remain ON.

Lights On Warning

The radio activates the lights on warning as requested by the body control module (BCM). The BCM sends a class 2 message to the radio indicating the chime frequency (fast rate) and duration (continuous).

• The ignition is OFF.

• The BCM determines that the driver's door is open (signal circuit is low).

• The BCM determines that the headlamp switch is in the park or head position.

Daytime Running Lamps (DRL)

The ambient light sensor is a light-sensitive transistor that varies its voltage signal to the body control module (BCM) in response to changes in the outside (ambient) light level. When the BCM receives this signal, the BCM turns ON either the DRL lamps or the headlamp relay for auto headlamp operation. Any function or condition that turns ON the headlamps will cancel the DRL operation.

Thirty seconds after you start the ignition with the headlamp switch set in the OFF position, the DRL will perform one of two actions:

• Illuminate the high beam headlamps at a reduced intensity in daylight conditions

• Illuminate the low beam headlamps in low light conditions

Battery positive voltage is applied at all times from the DRL/EXT LTS fuse in the underhood junction block to the coil side of the DRL relay. When the ambient light sensor indicates a day light condition, the BCM applies a ground to the DRL relay control circuit. This energizes the DRL relay allowing a ground to be applied from G101 through the DRL relay switch side to the left high beam headlamp. When the DRL relay is energized, battery positive voltage is applied from the EXT LTS fuse through the right high beam headlamp, to the left high beam headlamp. The high beam headlamps are now in series, and split the voltage so that the headlamps illuminate a half intensity. The DRL operates when the ignition switch is in the RUN position, and the parking brake is not set or the transmission is not in park. When these conditions have been met and the ambient light sensor indicates daytime conditions, the DRL will illuminate.

Fog Lamps

When the ignition switch is in the ON position and the headlamp switch is in either PARK or HEAD position, the fog lights illuminate whenever you press the fog lamp switch. The FOG RLY fuse in the top of the engine fuse block supplies battery positive voltage to both the fog lamp relay switch contacts and to the fog lamp relay coil circuit. The fog lamp relay coil is controlled by the Body Control Module (BCM). Whenever you press the fog lamp switch, the BCM fog lamp switch input is grounded. The BCM energizes the control circuit of the fog lamp relay coil. The current flows from the fog lamp relay to both front fog lamps and to ground G101. The fog lamps remain ON until you again press the front fog lamp switch, or until you cycle the ignition switch OFF and ON. The park lamps or low beam headlamps must be ON in order for the fog lamps to be illuminated. Fog lamp operation will be cancelled whenever the park lamps are turned OFF or the high beam headlamps have been selected.

Park, Tail, Marker Lamps, and License

The park, tail and marker lamps, including the license lamps, turn on when the headlamp switch is placed in either the PARK or the HEAD position, or anytime the headlamps are requested. The RT I/P #1 fuse in the RH I/P fuse block supplies battery positive voltage to both the park lamp relay switch contacts and to the park lamp relay coil circuit. The park lamp relay coil is controlled by the body control module (BCM). When the headlamp switch is placed in the PARK position, the BCM energizes the park lamp relay coil control circuit.

Current flows from the park lamp relay switch to both front and rear park lamp fuses and to their respective park/tail lamps. The front park lamps are grounded at G101. The rear park lamps are grounded at G302. The license plate lamps are a part of the rear park lamp circuit and are grounded at G302. The inadvertent power control feature prevents the park lamps from remaining on more than 10 minutes if left on. If the park lamps are turned on after the ignition switch has been turned OFF, or is in the ACCY position, they will remain on until turned off or until the battery runs dead.

A surveillance mode is available in Special Equipment Option (SEO) vehicles. The headlamps and park lamps may be disabled by using the emergency vehicle interior lamp switch.

Remote Keyless Entry Exterior Lamp Illumination

When the remote function actuation (RFA) module receives a door unlock command from the RFA transmitter, the RFA module will perform the following tasks:

• Ground the door unlock signal circuit to the body control module (BCM)

• Send a class 2 message to the BCM indicating that an UNLOCK command has been received

The BCM will then flash the park lamps twice. If the doors are closed when you use the RKE transmitter in order to lock the doors, the park lamps will flash twice. The park lamps will not flash if you use the RKE transmitter in order to open the rear compartment.

Turn Signal Lamps

The TURN SIGNAL fuse in the LH I/P fuse block supplies ignition positive voltage to the hazard and turn signal lamp flasher assembly. The HAZ SW fuse in the RH I/P accessory wiring junction block also supplies battery positive voltage to the hazard and turn signal lamp flasher assembly. The turn signal lamps may activate only when the ignition switch is in the ON or ACCY position.

When the turn signal switch is placed in either the left or right position, current flows from the flasher module's output to the turn signal switch assembly. The flasher module then sends an on-off voltage signal to either the left or the right turn signals and their instrument cluster (IPC) indicator. When you press the hazard switch, all the turn signal lamps and both of the IPC turn signal indicators will flash. The hazard and turn signal lamp flasher assembly is grounded at G201. The front turn signals are grounded at G101 and the rear turn signals are grounded at G302.

Turn Signal On

The Radio activates the turn signal on audible warning as requested by the body control module (BCM). The BCM sends a class 2 message to the radio indicating the chime frequency ( fast rate) and duration (2 seconds).

Stop Lamps

The BRAKE SW fuse in the RH I/P fuse block supplies battery positive voltage to the normally-open stop lamp switch. When you press the brake pedal the switch contacts close and battery positive voltage is supplied to the left and right stop lamp assemblies and to the center high mounted stop lamp (CHMSL). The left and right stop lamp along with the CHMSL are grounded at G302.

Rear Window Panel Lamps (SEO, RPO 6J6)

The rear window panel lamp system on Special Equipment Option (SEO) vehicles, consists of two red lensed lamps that function as auxiliary turn signal and stop lamps. The wiring necessary for the additional emergency lamps on SEO vehicles consists of battery positive voltage supplies, circuit breakers, an emergency flasher, and relays. The lamps are mounted to the rear window panel.

Rear Compartment Lid Lamps (SEO, RPO T53)

The rear compartment lid lamps on Special Equipment Option (SEO) vehicles, consists of two red lensed lamps that function as an auxiliary flashing warning lamp. The wiring necessary for the additional emergency lamps on SEO vehicles consists of battery positive voltage supplies, circuit breakers, an emergency flasher, and relays. The lamps are mounted on the inner trunk lid. When you raise the lid a switch closes and the lamps alternately flash.

Spot Lamps and Front Lamps (SEO, RPO 9C1, 9C6, 7X6 and 7X7)

The spot lamp system on Special Equipment Option (SEO) vehicles consists of either one left spot lamp (RPO 7X6), or two left and right spot lamps (RPO 7X7). The spot lamps are mounted to either the left or right hand windshield pillars and contain their own ON/OFF switch. Battery positive voltage is supplied to the spot lamps through their own respective fuses. All other wiring is blunt-ended to be used on SEO vehicles as necessary.

Surveillance Mode Switch (SEO)

The Surveillance Mode Switch turns off the daytime running lamps (or low beam headlamps and tail lamps during nighttime hours), instrument cluster, PRNDL and radio indicators. Interior courtesy lights are also disabled when switch is activated.

Backup Lamps

The B/U LAMP fuse in the RH I/P fuse block supplies battery positive voltage to the switch terminal of the backup lamps relay. The DIC/RKE fuse supplies battery positive voltage to the backup lamps relay coil terminal. When you place the gear selector lever in the REVERSE position, the powertrain control module (PCM) sends a class 2 message to the body control module (BCM). When these conditions occur, the BCM energizes the reverse lamp relay control circuit, closing the switch contacts, the current flows from the reverse lamp relay switch to the backup lamps. The backup lamps are grounded at G302.

Battery Rundown Protection / Inadvertent Power

The body control module (BCM) controls the lighting system through circuits that enable the park lamps, head lamps and fog lamps as well as the interior lamps. The BCM opens these enabling circuits 20 minutes after the ignition switch is turned OFF with no subsequent lamp switch activity. If the ignition switch is turned to any position other than OFF, or if a lamp switch is activated, during this 20-minute period, the timer will reset for another 20 minutes.

LIGHTING SYSTEM INDICATOR(S)

HIGH BEAM

The IPC illuminates the high beam indicator when the body control module (BCM) detects that the high beams are requested. The IPC receives a class 2 message from the BCM requesting illumination.

HIGHBEAM OUT

The IPC illuminates the HIGHBEAM OUT indicator in the message center when the body control module (BCM) detects an open in one of the highbeam lamp circuits. The IPC receives a class 2 message from the BCM requesting illumination. The HIGHBEAM OUT indicator illuminates for 60 seconds when the condition is present.

Turn Signals

The IPC illuminates the right or left turn signal indicator when the IPC detects a turn signal request or a hazard request. If the IPC determines that the turn signal is active for more than 1.2 km (0.75 mi), the IPC sends a class 2 message to the radio in order to activate an audible warning.

Interior Lighting Systems Description and Operation

Interior Lamps

The interior lamps consists of two groups, lamps that can not be dimmed and lamps that can be dimmed. This first group consists of lamps that may not be dimmed. This Includes those lamps that may be manually turned on by placing the interior lamp switch to the DOME position, or by opening a door or a compartment:

• Auxiliary dome lamp (SEO, RPO 6C7)

• Dome lamp

• Inside rear view mirror lamps

• Instrument panel (I/P) compartment lamp

• I/P courtesy lamps

• Reading lamps

• Rear compartment courtesy lamp

• Sunshade vanity mirror lamps

Battery positive voltage is applied at all times to the DIC/RKE fuse and to the switched side of the BATT RUNDOWN PROTECTION relay in the right I/P junction block. The DIC/RKE fuse supplies battery positive voltage to the coil side of the BATT RUNDOWN PROTECTION relay. When the ignition is turned to the ON position, the body control module (BCM) provides a ground to the courtesy lamp relay control circuit. This energizes the BATT RUNDOWN PROTECTION relay and applies battery positive voltage to I/P BRP fuse and to the TRK/ROOF/BRP fuse. Battery positive voltage is applied from the I/P BRP fuse to the I/P courtesy lamps, I/P compartment lamp and to the courtesy lamp supply voltage circuit to the BCM. Battery positive voltage is also applied from the TRK/ROOF/BRP fuse to the:

• Rear compartment courtesy lamp

• Dome lamp

• Inside rear view mirror lamps

• Roof rail/reading lamps assembly

• Sunshade vanity mirror lamps

If the BCM receives a door lock or unlock input signal, the BCM will activate the BATT RUNDOWN PROTECTION relay, which provides battery positive voltage to all interior courtesy lamps. When any door is opened, the door jam switch contacts close and the BCM receives a door-open input signal. The BCM then applies a ground to the interior lamp control circuit and to the courtesy lamp low control circuit illuminating the courtesy and dome lamps.

After all the doors are closed, the courtesy lamps remain illuminated for approximately 40 seconds. The courtesy lamps will also turn on and remain illuminated for approximately 15 seconds after the ignition key is removed, prior to any door being opened.

When the headlamp switch is placed in the DOME position, the BCM receives a ground signal. The BCM then applies a ground to the interior lamps control circuit. This illuminates the dome and roof rail lamps.

The courtesy lamps will normally turn off using the theater dimming feature. The BCM provides a pulse width modulated ground to all courtesy/reading, dome, and inside rear view mirror lamps for the theater dimming feature. The BCM will immediately turn off the courtesy lamps if a door lock command is received with all the doors closed, or if the ignition switch is turned to either the ON or RUN position.

The BCM activates the interior lighting output 15 seconds after receiving the class 2 message "Airbags Deployed" from the sensing and diagnostic module (SDM). The interior lamps remain activated for 25 minutes.

Auxiliary Dome Lamp (SEO, RPO 6C7)

An auxiliary dome lamp on special equipment option (SEO) vehicles is mounted to the headliner near the windshield. The auxiliary dome lamp is turned ON using a switch at its base.

Interior Lamps (SEO)

When the emergency vehicle interior lamp switch is turn to the OFF position, the interior lamps are deactivated immediately.

I/P Compartment Lamp

The I/P BRP provides battery positive voltage to the instrument panel compartment lamp. When the I/P compartment is opened, a switch closes, providing a ground circuit to G201, and the I/P compartment lamp illuminates.

Keyless Entry Interior Illumination

When the door key is used to unlock the doors, the BCM receives a door unlock signal. The BCM activates the interior lamps, provided the BCM has input signals indicating the following conditions:

• The ignition switch is OFF

• The courtesy lamp switch is OFF

• All the doors are closed

If the door locks are activated to the LOCK position, or if the ignition switch is turned to either the RUN or CRANK position the courtesy lamps turn off immediately, otherwise the courtesy lamps will remain on for approximately 40 seconds after the door is closed. The BCM turns the courtesy lights off through the theater dimming feature.

If the remote function actuator transmitter is used to unlock the doors or the trunk, or if the panic button is pressed, the BCM will keep the courtesy lamps on for approximately 15 seconds. If the door locks are activated to the UNLOCK or LOCK position, or if the ignition switch is turned to either the RUN or CRANK position, the courtesy lamps will turn off immediately.

The BCM keeps the courtesy lamps on for approximately 40 seconds after an alarm event is completed.

The courtesy lamps in special equipment option (SEO) vehicles may be disabled by using the emergency vehicle interior lamp switch, called surveillance mode.

Rear Compartment Lamp

The TRK/ROOF fuse provides battery positive voltage to the rear compartment lamp. When the rear compartment is opened, the rear compartment lid ajar switch closes, providing a ground circuit to G302 and the rear compartment lamp illuminates.

Sunshade Vanity Lamps

The TRK/ROOF fuse provides battery positive voltage to each vanity mirror lamp. When the vanity mirror cover on the sunshade is opened, a switch closes, providing a ground circuit to G302, and the vanity lamps illuminates.

Surveillance Mode Switch (SEO)

The surveillance mode switch turns off the daytime running lamps, or low beam headlamps and tail lamps during low light conditions, instrument cluster, Park, Reverse, Neutral, Drive, Low (PRNDL) and radio indicators. Interior courtesy lights are also disabled when the switch is activated.

Interior Lamps Dimming

The second group of interior lighting includes lamps which may be dimmed. This group uses a combination of class 2 controlled illumination and incandescent lamps:

• Ashtray lamp

• Door switches and window switches

• Fog lamp switch

• HVAC control head assembly

• Outside rear view mirror switches

• Radio

• Steering wheel controls

• Instrument panel cluster (IPC)

• Traction control switch

• Headlamp switch

• Hazard switch

• Heated seat switch

• The rear view mirror lamps

• Surveillance mode switch (SEO, 9C1/9C3)

The RH instrument panel (I/P) fuse block supplies battery positive voltage to both the coil and normally open switch contacts of the park lamp relay. When the body control module (BCM) energizes the park lamp relay, current flows from the park lamp relay switched contacts through the REAR PARK LP fuse to the I/P dimming switch. When dimming is selected, by moving the I/P dimming switch, all incandescent back lighting lamps (see schematics) and the BCM are provided with a variable voltage through the instrument panel lamp supply voltage #1 circuit. The incandescent back lighting lamps are then grounded at G201, G203 and G302. The BCM then applies a message signal to the class 2 circuit to the IPC and radio. The class 2 displays then dim to the level set by the I/P dimmer switch. When the I/P dimmer switch is moved from MIN to MAX, all class 2 displays and all incandescent back lighting respond from minimum intensity to maximum brightness.

Parade mode may be selected by manually turning on the park lamps during daylight conditions. The front park lamp circuit supplies voltage the HVAC assembly for a park lamp on input, and the display will become full bright. The BCM applies a message signal to the class 2 circuit to the IPC and radio commanding the displays to become full bright. The surveillance mode switch (SEO) overrides this feature.

Battery Rundown Protection / Inadvertent Power

The body control module (BCM) controls the lighting system through circuits that enable the park lamps, head lamps and fog lamps as well as the interior lamps. The BCM opens these enabling circuits 20 minutes after the ignition switch is turned OFF with no subsequent lamp switch activity. If the ignition switch is turned to any position other than OFF, or if a lamp switch is activated, during this 20-minute period, the timer will reset for another 20 minutes.

Body Control System

Schematic and Routing Diagrams Component Locator Diagnostic Information and Procedures Repair Instructions Description and Operation


Body Control System Schematics

Body Control System Schematics

Grounds, Power, DLC, and Keyless Entry ABS, Audible Warnings, Body Rear End, Horns, HVAC References to Lighting Doors, Engine Electrical, and Lighting

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Component Locator

Body Control System Component Views Body Control System Connector End Views

Body Control System Component Views Behind Left Side of Instrument Panel

(1) Body Control Module (BCM)

(2) Body Control Module Connector C3




(6) P101

(7) Remote Control Door Lock Receiver (RCDLR) Connector

Body Control System Connector End Views

Body Control Module, C1


• 12110244

• 24-Way F Micro-Pack 100 Series (PNK)


No. Function A1 DK BLU 1393 Interior Lamp Relay Coil Control

A2 WHT 1080 Park Lamp Relay Control

A3 ORN 2140 Battery Positive Voltage

A4 -- -- Not Used

A5 LT GRN 1037 BCM Class 2 Serial Data

A6 BLK 1050 Ground

A7 BLK 1050 Ground

A8 LT GRN/BLK 592 DRL Relay Control

A9 -- -- Not Used

A10 WHT 156 Courtesy Lamp Low Control

A11 LT GRN 377 Keyless Entry Serial Data (w/o 9C1/9C3/9C6)

A12 PPL 1500 Ignition 0 Voltage

B1 -- -- Not Used

B2 DK GRN/

WHT 1317

Fog Lamp Relay Control (Impala LS/ Monte Carlo SS)

B3 BLK/WHT 1969 Headlamp High Beam Relay Control

B4 -- -- Not Used

B5 BLK 28 Horn Relay Control

B6 DK BLU 38 Backup Lamp Relay Control

B7 BLK 1050 Ground

B8 TAN/WHT 816 A/T Shift Lock Solenoid Supply Voltage

B9 WHT 1459 Security System Sensor Supply Voltage

B10 PNK 1200 Headlamp High Beam Signal

B11 GRY 8 Instrument Panel Lamp Supply Voltage - 1

B12 BLK 1835 Security System Sensor Low Reference



• 12110088

• 24-Way F Micro-Pack 100 Series (GRY)


No. Function A1 ORN 1940 Battery Positive Voltage

A2 LT BLU 1344 Trunk Release Relay Control

A3 YEL 1836 Security System Sensor Signal

A4 ORN 1840 Battery Positive Voltage

A5 LT GRN/BLK 1137 DRL Ambient Light Sensor Signal

A6 TAN 294 Door Lock Actuator Unlock Control

A7 GRY 295 Door Lock Actuator Lock Control

A8 GRY 157 Interior Lamp Control

A9 BRN/WHT 1571 Traction Control Switch Signal (w/o 9C1/9C3/9C6)

A10 PNK 139 Ignition 1 Voltage

A11 RED/BLK 744 Trunk Ajar Switch Signal

A12 TAN 694 Driver Door Lock Actuator Unlock Control

B1 -- -- Not Used

B2 YEL/BLK 1138 DRL Ambient Light Sensor Low Reference

B3 ORN/BLK 781 Door Lock Switch Signal

B4 YEL 10 Headlamp Switch Signal

B5 BLK/WHT 1251 Ground

B6 DK BLU/

WHT 1495 Courtesy Lamp Switch Signal

B7 PPL 328 Surveillance Mode Switch Signal (9C1/9C3/9C6)

B8 ORN 480 Load Management Control

B9 BLK 707 RAP Relay Coil Supply Voltage

B10-B12 -- -- Not Used



• 12084945

• 16-Way F Micro-Pack 100 Series (GRY)


No. Function A1 DK BLU/WHT 727 Door Open Switch Signal

A2 LT BLU 74 Park Lamp Switch Signal

A3 -- -- Not Used

A4 DK GRN/

WHT 762 A/C Request Signal

A5 YEL 43 Accessory Voltage

A6 -- -- Not Used

A7 BLK 1576 Trunk Release Switch Signal

A8 DK BLU 49 Driver Door Open Switch Signal

B1 LT GRN 80 Key In Ignition Switch Signal

B2 DK BLU/


B3 LT GRN 262 Driver Door Key Switch Signal (w/o 9C1/9C3/9C6)

B4 -- -- Not Used

B5 DK GRN 389 Vehicle Speed Signal

B6 LT GRN 1844 Park Brake Indicator Supply Voltage

B7 ORN 192 Front Fog Lamp Switch Signal (Impala LS/ Monte Carlo SS)

B8 -- -- Not Used


Diagnostic Starting Point – Body Control System Scan Tool Output Controls Scan Tool Data List Scan Tool Data Definitions Diagnostic Trouble Code (DTC) List DTC B1000 DTC B1007 DTC B1009 DTC B1339 DTC B1349 DTC B1440 DTC B1507 or B1508 DTC C0550 Symptoms – Body Control System Power Mode Mismatch Control Module References

Diagnostic Starting Point - Body Control System Begin the diagnosis of the body control system by performing the Diagnostic System Check for the system in which the customer concern is apparent. The Diagnostic System Check will direct you to the correct procedure for diagnosing the system and where the procedure is located.

Diagnostic Trouble Code (DTC) List DTC Diagnostic Procedure Module(s)

B1000 DTC B1000 BCM, DIC, EBCM, IPC, OnStar Module, PCM, Radio, SDM

B1007 DTC B1007 Radio

B1009 DTC B1009 OnStar Module, Radio

B1339 DTC B1339 BCM

B1349 DTC B1349 BCM

B1440 DTC B1440 BCM

B1507 DTC B1507 or B1508 BCM

B1508 DTC B1507 or B1508 BCM

C0550 DTC C0550 EBCM

Symptoms - Body Control System Important: Review the system operation in order to familiarize yourself with the system functions. Refer to Body Control System Description and Operation .

Visual/Physical Inspection

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

Power Mode Mismatch

• Inspect for aftermarket devices which could affect the operation of the body control system. Refer to Checking Aftermarket Accessories in Wiring Systems.

• Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Control Module References Control Module Repair Instructions Diagnostic System Check Schematic

BCM Refer to Body Control Module

Replacement --

Refer to Body Control System Schematics

DIC Refer to Roof Console

Replacement in Instrument Panel, Gages and Console

Refer to Diagnostic System Check - Driver Information

Systems in Instrument Panel, Gages and Console

Refer to Driver Information System Schematics in

Instrument Panel, Gages and Console

EBCM Refer to Electronic Brake Control Module Replacement in Antilock

Brake System

Refer to Diagnostic System Check - ABS in Antilock Brake

System

Refer to Antilock Brake System Schematics in Antilock Brake System

IPC Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console

Refer to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gages and

Console

Refer to Instrument Cluster Schematics in Instrument Panel, Gages and Console

PCM

Refer to Powertrain Control Module Replacement in Engine

Controls (3.4L) or Refer to Powertrain Control Module

Replacement in Engine Controls (3.8L)

Refer to Diagnostic System Check - Engine Controls in Engine Controls (3.4L) or

Diagnostic System Check - Engine Controls in Engine

Controls (3.8L)

Refer to Engine Controls Schematics in Engine

Controls (3.4L) or Engine Controls Schematics in Engine Controls (3.8L)

Radio Refer to Radio Replacement in

Entertainment

Refer to Diagnostic System Check - Radio/Audio System in

Entertainment

Refer to Radio/Audio System Schematics in

Entertainment

SDM Refer to Inflatable Restraint

Sensing and Diagnostic Module Replacement in SIR

Refer to Diagnostic System Check - SIR in SIR

Refer to SIR Schematics in SIR

Repair Instructions

Body Control Module Replacement Body Control Module (BCM) Programming/RPO Configuration

Body Control Module Replacement Removal Procedure

Important: You must perform the new body control module (BCM) setup when replacing the BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration .

1. Disconnect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.

2. Remove the left instrument panel insulator. Refer to Instrument Panel Insulator Panel Replacement - Left Side in Instrument Panel, Gages and Console.

3. Disconnect the BCM electrical connectors (2,3,4). 4. Remove the BCM (1).


1. Install the body control module (BCM) (1). 2. Connect the BCM electrical connectors (2,3,4). 3. Install the left instrument panel insulator. Refer to Instrument Panel Insulator Panel Replacement - Left

Side in Instrument Panel, Gages and Console. 4. Connect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and

Connection in Engine Electrical. 5. Perform the new BCM setup. Refer to Body Control Module (BCM) Programming/RPO Configuration .

Body Control Module (BCM) Programming/RPO Configuration Introduction

During body control module (BCM) related service, the procedures below are designated to set-up the BCM correctly. Before you start, read these procedures carefully and completely.

Setup New Body Control Module (BCM)

Important:

1. Connect a Scan Tool (Tech 2) to the Data Link Connector (DLC). 2. Turn the ignition switch on. 3. Select Diagnostics and input all of the required data when prompted by the Scan Tool (Tech 2). 4. Select BODY CONTROL MODULE. 5. Select SPECIAL FUNCTIONS. 6. Select Setup New BCM. 7. Note, Input all of the required data when prompted by the scan tool. 8. Select Setup SDM Part Number in BCM, and follow the onscreen directions. 9. Select New VIN, and follow the onscreen directions.

10. Select Option Configuration, and follow the onscreen directions. . 11. Select Point of Sale, and follow the onscreen directions. . 12. Exit back to the SPECIAL FUNCTIONS menu. 13. When the BCM, VIN, Point of Sale and Option Configuration have been entered, proceed with the Theft

Deterrent Re-learn procedure. 14. If the scan tool displays UNABLE TO PROGRAM BCM. BCM IS SECURED, then the BCM must be replaced and

this procedure must be repeated on a new BCM.

NOTE: After the above procedure has been completed, personalization of the BCM defaults to a default setting. Inform the customer that the personalization settings must be set again.

Important: After programming, perform the following to avoid future misdiagnosis:

1. Turn the ignition OFF for 10 seconds. 2. Connect the scan tool to the data link connector. 3. Turn the ignition ON with the engine OFF. 4. Use the scan tool in order to retrieve history DTCs from all modules. 5. Clear all history DTCs.

• The BCM will not function properly if the Setup New BCM procedure is not performed.

• Make sure the battery is fully charged before performing the setup procedure.

• Make sure all disconnected devices and connectors have been reconnected

• Perform the Theft Deterrent Re-learn procedure after successfully finishing the Setup New BCM procedure. Refer to Programming Theft Deterrent System Components in Theft Deterrent. If the Theft Deterrent Re-learn procedure is not performed after a BCM replacement, the following conditions may occur:

- The vehicle will not be protected against theft by the PASSLOCK system.

- The engine will not crank nor start.


Body Control System Description and Operation

Body Control System Description and Operation

BCM Functions

The Body Control Module (BCM) performs multiple body control functions. The BCM can control devices directly connected to its outputs based on input information obtained from two sources:

• sensors and switches that are directly connected to the BCM

• by receiving information from other vehicle systems connected to the class 2 serial data link.

The BCM evaluates this information and controls certain body control systems by commanding outputs on or off.

The BCM is also capable of controlling other vehicle systems that are not directly wired to the BCM. The BCM does this by sending specific messages on the class 2 serial data link. The vehicle system capable of performing a required function will respond to the BCM message.

The BCM controls these functions:

• Audible warnings, refer to Audible Warnings Description and Operation in Instrument Panel, Gages and Console.

• Interior lighting, refer to Interior Lighting Systems Description and Operation in Lighting Systems.

• Automatic door locks, refer to Power Door Locks Description and Operation in Doors.

• Automatic headlamp control, refer to Exterior Lighting Systems Description and Operation in Lighting Systems.

• Keyless entry (AUO option), refer to Keyless Entry System Description and Operation in Keyless Entry.

• Passlock theft deterrent, refer to Vehicle Theft Deterrent (VTD) Description and Operation in Theft Deterrent

• Content theft deterrent, refer to Content Theft Deterrent (CTD) Description and Operation in Theft Deterrent

• Retained Accessory Power (RAP), refer to Retained Accessory Power (RAP) Description and Operation in Retained Accessory Power.

Simple Power Mode Example

The power mode signal may be as simple as a B+ input wired to a particular ignition switch contact. If this is also the B+ supply to the module/device, the module/device will only operate with the ignition contact closed to B+. An example of this is the starter relay when it is wired directly to the CRANK/START contact of the ignition switch. When the CRANK/START contacts are closed, the starter relay is energized and provides a current source to the starter and starter solenoid. When the ignition switch leaves the CRANK/START position, the switch contacts open and the starter relay is de-energized. This removes the current source from the starter and solenoid and the starter operation stops.

Serial Data Power Mode

On vehicles that have several control modules connected by serial data circuits, one module is the power mode master (PMM). On this vehicle the PMM is the body control module (BCM). The BCM receives three signals/circuits from the ignition switch: Acc/Run/Crank (Ignition 0), Run/Crank (Ignition 1) and Acc/Run (Accessory).

To determine the correct power mode the BCM uses:

• the state of these signals/circuits, either switch closed (B+ = 1) or switch open (open = 0)

• the sequence of switch closures received by the BCM

• the status of the engine run flag

The chart below indicates the modes detected and transmitted by the BCM:

Power Mode Engine Run Flag Sampled Ignition Signal State

Selected/ Expected Serial Data Accessory Ignition 1 Ignition 0

OFF 0 0 0 0

RAP 0 0 0 1 to 0

ACCESSORY 0 1 0 1

RUN 0 1 1 1

CRANK 0 0 1 1

RUN 1 1 1 1

NOTE: Any ignition switch states not covered in this table indicates a DTC setting situation.

Fail-safe Operation

Since the operation of the vehicle systems depends on the power mode, there is a fail-safe plan in place should the BCM fail to send a power mode message. The fail-safe plan covers those modules using exclusively serial data control of power mode as well as those modules with discrete ignition signal inputs.

Serial Data Messages

The modules that depend exclusively on serial data messages for power modes stay in the state dictated by the last valid BCM message until they can check for the engine run flag status on the serial data circuits. If the BCM fails, the modules monitor the serial data circuit for the engine run flag serial data. If the engine run flag serial data is True, indicating that the engine is running,

the modules fail-safe to RUN. In this state the modules and their subsystems can support all operator requirements. If the engine run flag serial data is False, indicating that the engine is not running, the modules fail-safe to OFF-AWAKE. In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.

Discrete Ignition Signals

Those modules that have discrete ignition signal inputs also remain in the state dictated by the last valid BCM message received on the serial data circuits. They then check the state of their discrete ignition input to determine the current valid state. If the discrete ignition input is active, B+, the modules will fail-safe to the RUN power mode. If the discrete ignition input is not active, open or 0 voltage, the modules will fail-safe to OFF-AWAKE. In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.

Theft Deterrent



Vehicle Theft Deterrent (VTD) Description and Operation

Vehicle Theft Deterrent (VTD) Description and Operation

Passlock™ System

The theft deterrent system has been incorporated into the body control module (BCM). The theft deterrent system prevents the vehicle operation if the correct key is not used in order to start the vehicle. The ignition key turns the ignition lock cylinder. The cylinder rotation produces an analog voltage code in the Passlock™ sensor. This voltage code is received by the BCM. The BCM compares the voltage code to the previously learned voltage code. If the codes match, a class 2 message is sent from the BCM to the powertrain control module (PCM). The message enables the fuel injectors and the crank relay.

The design of the Passlock™ system is to prevent vehicle theft by disabling the engine unless the ignition lock cylinder rotates properly by engaging the correct ignition key. The system is similar in concept to the passkey system. However, the Passlock™ system eliminates the need for a key mounted resistor pellet. The components of the Passlock™ system are as follows:

• The ignition lock cylinder

• The ignition switch

• The Passlock™ sensor

• The body control module (BCM)

• The SECURITY indicator

• The powertrain control module (PCM)

Ignition Lock Cylinder and Housing

The Passlock™ sensor and ignition lock cylinder are one assembly. The Passlock™ sensor is separate from the key and lock cylinder. The key and the lock cylinder work together in order to determine if the proper ignition key was used to start the vehicle.

In the event of an open Class 2 serial data line between the BCM and the PCM, the vehicle will become fail-enabled if the PCM has already received the password from the BCM for that ignition cycle (the engine is running). In this event, the following conditions occur:

• The SECURITY indicator will be ON continuously.

• The PCM will become fail-enabled for future ignition cycles.

If a failure in the Class 2 serial data line occurs before the ignition cycle, when the PCM is not fail-enabled, the following conditions occur:

• The PCM will never receive a valid password in order to enable the fuel injectors and crank relay.

• The vehicle will not start.

Ignition Switch

The electrical switching portion of the ignition lock cylinder assembly is separate from the key and lock cylinder. The electrical switch portion and the key and lock cylinder synchronize and work in conjunction through the action of the mechanical assembly between the two components.

Passlock™ Sensor

The Passlock™ sensor contains 2 hall effect sensors. The tamper hall effect sensor is on the top. The security hall effect sensor is under the tamper hall effect sensor. Both of the hall effect sensors monitor the magnet of the lock cylinder through an opening. The tamper hall effect sensor is physically placed on top of the security hall effect sensor. This arrangement enables the tamper hall effect sensor to engage first if an intruder attempts to bypass the Passlock™ sensor by placing a large magnet around that area of the steering column. There is a tamper resistor inside the Passlock™ sensor in order to help prevent tamper to the system. Passlock™ equipped vehicles have a selection of 10 different security resistors ranging from 0.5K ohms up to 13.6K ohms. Installing one of the security resistors inside the Passlock™ sensor will generate a unique Passlock™ code. All 10 combinations of the Passlock™ sensor have the same part number.

Body Control Module

The body control module (BCM) contains the theft deterrent system logic. The BCM reads the Passlock™ data from the Passlock™ sensor. If the Passlock™ data is correct, the BCM will send a class 2 message to the PCM to enable the fuel injectors and crank relay.

During the tamper mode the vehicle may start. The vehicle will then stall. If the BCM receives the wrong Passlock™ data, the VTD system will immediately go into the tamper mode. The tamper mode will lock-out the vehicle fuel injectors and crank relay for 10 minutes. The SECURITY indicator will flash while the VTD is in the tamper mode.

If the Passlock™ sensor sends a correct password to the BCM when the ignition is in the ON position, the BCM will send a fuel enable and crank relay enable signal to the PCM.

SECURITY Indicator

The SECURITY indicator appears on the message center inside the instrument cluster. If the SECURITY indicator flashes or if the SECURITY indicator lights continuously during vehicle operation, refer to the system diagnosis.

Powertrain Control Module

The PCM communicates with the BCM over the Class 2 serial data line. When the BCM determines an incorrect password, it sends a Class 2 serial data password to the PCM in order to disable the crank relay and fuel injection system. If the BCM receives the expected voltage from the Passlock™ sensor, the BCM sends a class 2 serial data password to the PCM in order to enable the crank relay and fuel injection system. The PCM then allows the vehicle to start normally.

Fuel Lockout Cycle

The Passlock™ system has a lockout cycle of approximately 10 minutes. Once the vehicle is in the lockout cycle, the vehicle remains in the lockout cycle for 10 minutes, even if the ignition switch is turned from the ON position to the OFF position.

The Passlock™ system uses the lockout cycle in order to synchronize all of the Passlock™ components when any Passlock™ related part is replaced. The Passlock™ system requires 3 consecutive lockout cycles in order to complete the 30 minute learn procedure for a changed component.

Changing the Passlock™ Components

The design of the Passlock™ system is to prevent theft even if the various theft deterrent parts change. The parts that can no longer be changed without the possibility of going into a tamper mode are:

• The Passlock™ sensor

• The BCM

• The PCM

If you replace any of these parts the vehicle may not start for 10 minutes. This is the long tamper mode. If this occurs, the system must go through a long tamper mode cycle. During this time the SECURITY indicator will be flashing for the full 10 minutes and DTC B3031 will be set. The BCM and the PCM require the full 10 minutes in order to complete a learn cycle. The ignition switch must remain in the ON position until the SECURITY indicator stops flashing. You will need to repeat the cycle if the ignition switch does not remain in the ON position. When replacing any of the above parts, perform the Programming Theft Deterrent System Components procedure.

The design of the Passlock™ system is to prevent the vehicle operation if the proper ignition key is not used in order to start the vehicle. The mechanical key, in normal operation, will turn the ignition lock cylinder. The Passlock™ sensor monitoring the position of the lock cylinder will relay the Passlock™ data to the body control module (BCM). The BCM will determine the validity of the Passlock™ data. The BCM will send a password to the powertrain control module (PCM). When the PCM receives the correct password the PCM allows the crank relay and fuel injectors to operate normally. The Passlock™ system requires the PCM and the BCM to communicate the various functions in order to operate. These functions transmit over the class 2 serial data line. For an explanation of the class 2 serial data description and operation refer to Data Link Communications Description and Operation in Data Link Communications.

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