sid: 22 mid: 128 fmi: 2, 3 & 8 crank speed sensor

www.TruckFaultCodes.com

Copyright 2017

VOLVO

SID: 22

MID: 128

FMI: 2, 3 & 8

CRANK SPEED SENSOR

Crank Speed Sensor Circuit

FAILURE MODE IDENTIFIER (FMI)

2 (Data Erratic), 3 (Shorted High), 8 (Abnormal Frequency)

CIRCUIT DESCRIPTION

The Crank Speed Sensor is an inductive sensor that will generate a variable voltage signal when the sensor's magnetic field is excited. The Crank Speed Sensor is installed near the flywheel. When the engine is running the flywheel's teeth rotate past the sensor's tip and voltage pulses are generated. The Engine Management System (EMS Module) monitors the frequency of the signal generated by the Crank Speed Sensor and calculates the engine RPM. The air gap between the sensor tip and the flywheel teeth can influence the sensor's output signal and should be checked if SID 22 is set or is setting intermittently.

LOCATION

The Crank Speed Sensor is located on the left side of the engine on the flywheel housing.

http://www.truckfaultcodes.com/


Copyright 2017

2

CODE SETTING CONDITIONS

If the Engine Management System (EMS) Module calculates a significant difference between the Crank Speed Sensor input signal and the CAM Speed Sensor input signal, the EMS Module will turn on the Electronic Malfunction Lamp (EML) and SID 22 will set. If the engine speed signals agree, the fault will become inactive. The engine and tachometer will continue to operate when SID 22 is set because the EMS Module will use the CAM Speed Sensor signal to calculate engine speed.

NOTE: Electrical problems can cause this fault to be

generated, and electrical diagnostics are provided in this

section. Mechanical problems can also cause temporary or

permanent speed signal errors. After all electrical possibilities

have been ruled out, check mechanical conditions that could

cause vibration or signal errors. Such conditions include but

are not limited to:

− Faulty Engine Vibration Damper

− Contaminated sensor tips

− Missing or chipped gear teeth

− Improperly installed Flywheel Ring Gear

− Incorrect Flywheel

− Contaminated Flywheel Ring Gear

− Improperly adjusted sensor

− Excessive Driveshaft backlash

− Improperly balanced engine components.

NOTE: FMI 3 will only be seen as active with the engine OFF.

In all cases the SID 22 FMI will change to 2 when the engine

is started.



Copyright 2017

3

TROUBLESHOOTING STEPS

Test 1 – Checking for SID 22.

1. Verify that SID 22 is set.

Is SID 22 set?

Yes – If SID 22 is set, go to “Test 2 — Checking for

an Open or Short in the Sensor”.

No – If SID 22 is not set, wiggle the harness and

connectors to try to set the code.

Test 2 – Checking for an Open or Short in the Sensor.

Crank Speed Sensor (Sensor Side)

1. Turn the ignition key OFF.

2. Disconnect the Crank Speed Sensor.

3. Measure the resistance between terminals 1 and 2 on the sensor side of the Crank Speed Sensor

harness connector.

Is the resistance between 775–945 ohms?

Yes – If the resistance is between 775–945 ohms, go

to “Test 3 — Checking for a Short to Ground in the

Sensor”.

No – If the resistance is NOT between 775–945

ohms, go to, check the Crank Speed Sensor pigtail

connector and wiring for damage. If the connector

and wiring are NOT damaged, replace the Crank

Speed Sensor.



Copyright 2017

4

Test 3 – Checking for a Short to Ground in the Sensor.

Crank Speed Sensor (Sensor Side)


2. Disconnect the Crank Speed Sensor connector.

3. On the sensor side of the harness connector, check for continuity between pin 1 and a good ground.

Also check for continuity between pin 2 and a good ground.

Does continuity exist between either pin and ground?

Yes – If continuity exists between either pin and

ground, replace the sensor.

No – If there is NO continuity, go to “Test 4 —

Checking for a Short Circuit to Voltage in the Sensor

Signal Line”.

Test 4 – Checking for a Short Circuit to Voltage in the Sensor Signal Line.

EMS Module Connector A (Harness Side)



Copyright 2017

5


2. Disconnect connectors A and B from the Engine Management System (EMS) Module.

3. Turn the ignition key ON.

4. Measure the voltage between EMS Module connector A pin 38 and a good ground.

Is the measured voltage less than 0.5 volts?

Yes – If the measured voltage is less than 0.5 volts,

go to “Test 5 — Checking for a Short Circuit to

Voltage in the Sensor Return Line”.

No – If the measured voltage is greater than 0.5

volts, go to “Test 6 — Checking for a Pin to Pin Short

Circuit to Voltage”.

Test 5 – Checking for a Short Circuit to Voltage in the Sensor Return Line.



2. Disconnect connectors A and B from the EMS Module.

3. Turn the ignition key ON.

4. Measure the voltage between EMS Module connector A pin 37 and a good ground.

Is the measured voltage less than 0.5 volts?

Yes – If the measured voltage is less than 0.5 volts,

go to test.

No – If the measured voltage is greater than 0.5

volts, go to “Test 7 — Checking for a Short Circuit to

Ground” and “Test 8 — Isolating the Short Circuit to

Voltage”.



Copyright 2017

6

Test 6 – Checking for a Pin to Pin Short Circuit to Voltage.




3. Check for continuity between EMS Module connector A pin 38 and all other pins on EMS Module

connectors A and B.

Does continuity exist between pin 38 and any other pin?

Yes – If continuity exists between pin 38 and any

other pin, pin 38 is shorted to one of the other EMS

Module circuits. Locate and repair the short circuit to

voltage in the connector.

No – If there is NO continuity, the sensor signal line

is shorted to voltage somewhere else in the harness.

Locate and repair the short to voltage.



Copyright 2017

7

Test 7 – Checking for a Short Circuit to Ground.


2. Disconnect EMS Module connector A.


4. Check for continuity between EMS Module connector A pin 38 and a good ground and between EMS

Module connector A pin 37 and a good ground.

Does continuity exist?

Yes – If there is continuity to ground on either

circuit, go to “Test 10 — Isolating the Short

Circuit to Ground”.


Checking for a Pin to Pin Short Circuit in the

Harness”.



Copyright 2017

8

Test 8 – Isolating the Short Circuit to Voltage.



3. Check for continuity between EMS Module connector A pin 37 and all other pins on EMS Module

connectors A and B.

Does continuity exist between pin 37 and any other pin?

Yes – If continuity exists between pin 37 and any

other pin, pin 37 is shorted to one of the other EMS

Module circuits. Locate and repair the short circuit to

voltage.

No – If NO continuity exists, the return line is shorted

to voltage somewhere else in the harness. Locate

and repair the short circuit to voltage.



Copyright 2017

9

Test 9 – Checking for a Pin to Pin Short Circuit in the Harness.



3. Disconnect EMS Module connectors A and B.

4. Check for continuity between EMS Module connector A pins 37 and 38 versus all other pins on EMS

Module connectors A and B.


Yes – If continuity exists between pin 37 or pin 38

and any other pin, the suspect pin is shorted

to one of the other EMS Module circuits.

Locate and repair the short circuit.


Checking for an Open Circuit in the Harness”.



Copyright 2017

10

Test 10 – Isolating the Short Circuit to Ground.



3. Disconnect EMS Module connectors A and B.

4. Check for continuity between the circuit (connector A pin 37 or 38) that showed continuity in test 7 and

all other pins on EMS Module connectors A and B.


Yes – If continuity exists, the suspect pin is shorted

to one of the other EMS Module circuits. Locate and

repair the short circuit.

No – If there is NO continuity, the suspect pin is

shorted to ground somewhere else in the harness.

Locate and repair the short circuit.



Copyright 2017

11

Test 11 – Checking for an Open Circuit in the Harness.


2. Disconnect the Crank Speed Sensor connector.


4. Connect a jumper between EMS Module connector A pin 38 and EMS Module connector A pin 37.

5. Check for continuity between pins 1 and 2 on the harness side of the Crank Speed Sensor connector.


Yes – If continuity exists, go to “Test 12 — Checking

for an Open Circuit at the Sensor End of the

Harness”.


Checking for a Faulty EMS Module or a Loose EMS

Module Connector”.



Copyright 2017

12

Test 12 – Checking for an Open Circuit at the Sensor End of the Harness.



2. Connect the Crank Speed Sensor.


4. Measure the resistance between EMS Module connector A pins 37 and 38.

Is the resistance between 775-945 ohms?

Yes – If the resistance is between 775-945 ohms, go

to “Test 13 — Checking for a Faulty EMS Module or

a Loose EMS Module Connector”.

No – If the resistance is not within this range, there is

an open circuit or high resistance connection at the

sensor harness connector. Repair the connector if

possible, otherwise, replace the sensor.

Test 13 – Checking for a Faulty EMS Module or a Loose EMS Module Connector.

NOTE: Before replacing the Engine Control Unit (EMS Module), check the sensor for proper adjustment. Refer

to the OEM Procedures information for the installation and adjustment procedure and shim part numbers.


2. Connect the Crank Speed Sensor connector.

3. Connect EMS Module connectors A and B.

4. Start the engine.



Copyright 2017

13

Is SID 22 still active?

Yes – If SID 22 is still active, check the Engine

Management System (EMS Module) and connectors

for dirt, loose or broken pins, or repairable damage.

If no problems are evident, or they are not

repairable, replace the EMS Module and retest the

system.

No – If SID 22 is NOT active, the diagnostic

procedures have corrected the problem. Check all

connectors to ensure proper connections.


sid: 22 mid: 128 fmi: 2, 3 & 8 crank speed sensor

Documents