trouble codes obdii[1]

7/31/2019 Trouble Codes OBDII[1]

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Diagnostic Trouble Code (DTC) Descriptions

1999 PCED OBDII SECTION 4: Diagnostic Subroutines


DTC Description Possible Causes Diagnostic Aides

P0102 - Mass AirFlow (MAF)Circuit Low Input

The MAF sensorcircuit is monitoredby the PCM for low

air flow (or voltage)input through thecomprehensivecomponent monitor(CCM). If during keyON engine runningthe air flow (orvoltage) changesbelow a minimumcalibrated limit, thetest fails.

q MAF sensordisconnected

q MAF circuit open toPCM

q VPWR open to MAFsensor

q PWR GND open to MAFsensor

q MAF RTN circuit open toPCM

q MAF circuit shorted toGND

q Intake air leak (nearMAF sensor)

q A closed [throttleindication throttleposition (TP) sensorsystem]

q Damaged MAF sensorq Damaged PCM

A MAF V PID (MAF PID)reading less than 0.23 vol(Refer to equivalent

grams/second chart inPinpoint Test DC) incontinuous memory or keyON and engine runningindicates a hard fault.

P0103 - Mass AirFlow (MAF)Circuit High Input

The MAF sensorcircuit is monitoredby the PCM for highair flow (or voltage)

input through thecomprehensivecomponent monitor(CCM). If during keyON engine OFF orkey ON enginerunning the air flow(or voltage) changesabove a maximumcalibrated limit, thetest fails.

q MAF sensor screen isblocked

q MAF circuit shorted toVPWR

q Damaged MAF sensorq Damaged PCM

A MAF V PID (MAF PID)reading less than 4.6 volts(Refer to equivalentgrams/second chart in

Pinpoint Test DC) incontinuous memory or keyON and engine runningindicates a hard fault.

P0106 -Barometric(BARO) PressureSensor CircuitPerformance

Baro sensor input tothe PCM ismonitored and is notwithin the calibratedvalue.

q Slow responding BAROsensor

q Electrical circuit failureq Damaged BARO sensorq Damaged PCM

s VREF voltage should bbetween 4.0 and 6.0 v

s PID reading is infrequency

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P0107 - BAROSensor LowVoltage Detected

Sensor operatingvoltage is less than5.0 volts (VREF), asa result it failedbelow the minimumallowable calibratedparameter.

q Open in the circuit, orshort to ground

q VREF circuit open, orshort to ground

q Damaged BARO sensorq Damaged PCM

s VREF should be greatthan 4.0 volts

s PID reading is infrequency

P0108 - BARO

Sensor HighVoltage Detected

Sensor operating

voltage is greaterthan 5.0 volts(VREF), as a result itfailed abovemaximum allowablecalibratedparameter.

q VREF shorted to VWPRq

BARO signal shorted toVPWRq Damaged BARO sensorq Damaged PCM

s VREF should be less t

6.0 volts.q PID reading is in

frequency

P0109 - BAROSensor CircuitIntermittent

The sensor signal tothe PCM is failingintermittently.

q Loose electricalconnection

q Damaged BARO sensor

Check harness andconnection.

P0112 - Intake Air

Temperature(IAT) Circuit LowInput

Indicates the sensor

signal is less thanSelf-Test minimum.The IAT sensorminimum is 0.2 voltsor 121C (250F).

q Grounded circuit inharness

q Damaged sensorq Improper harness

connectionq Damaged PCM

s Using signal simulationdisconnect sensor andsimulate 1.0V on senssignal circuit. Simulate1.0V signal and scan Pvoltage value should bsimilar. If voltage is simcheck sensor, if voltagnot similar check relatecircuit and PCM.

P0113 - Intake Air

Temperature(IAT) Circuit HighInput

Indicates the sensor

signal is greater thanSelf-Test maximum.The IAT sensormaximum is 4.6 voltsor -50C (-46F).

q Open circuit in harnessq

Sensor signal short topowerq Damaged sensorq Improper harness


s Using signal simulation

disconnect sensor andsimulate 1.0V on senssignal circuit. Simulate1.0V signal and scan Pvoltage value should bsimilar. If voltage is simcheck sensor, if voltagnot similar check relatecircuit and PCM.

P0117 - EngineCoolant

Temperature(ECT) Circuit LowInput

Indicates the sensorsignal is less than

Self-Test minimum.The ECT sensorminimum is 0.2 voltsor 121C (250F).Note on somevehicles that are notequipped with anECT sensor, CHTcan be used and canset this DTC.

q Grounded circuit inharness

q Damaged sensorq Improper harness


s Using signal simulationdisconnect sensor and

simulate 1.0V on senssignal circuit. Simulate1.0V signal and scan Pvoltage value should bsimilar. If voltage is simcheck sensor, if voltagnot similar check relatecircuit and PCM.


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P0118 - EngineCoolantTemperature(ECT) CircuitHigh Input

Indicates the sensorsignal is greater thanSelf-Test maximum.The ECT sensormaximum is 4.6 voltsor -50C (-46 F).Note on somevehicles that are not

equipped with anECT sensor, CHTcan be used and canset this DTC.

q Open circuit in harnessq Sensor signal short to

powerq Damaged PCMq Improper harness

connectionq Damaged sensor

s Using signal simulationdisconnect sensor andsimulate 1.0V on senssignal circuit. Simulate1.0V signal and scan Pvoltage value should bsimilar. If voltage is simcheck sensor, if voltag

not similar check relatecircuit and PCM.

P0121 - ThrottlePosition (TP)CircuitPerformanceProblem

The TP sensorcircuit is monitoredby the PCM for anone closed throttleposition at idle. If keyON engine runningself-test terminates

upon placing thetransmission rangeselector in gear(DRIVE orREVERSE) or whenclosing the throttle(idle) after opening it(in PARK orNEUTRAL) the TPclosed throttleposition is not

attained, the testfails.

q Binding throttle linkageq Damaged throttle bodyq TP circuit open to PCMq Damaged TP sensorq SIG RTN circuit open to

TP sensor

Drive vehicle, bring to a stturn key OFF. Start vehiclrun key ON engine runninself-test at idle. AccessKOER diagnostic troublecodes on scan tool.

P0122 - ThrottlePosition (TP)Circuit Low Input

The TP sensorcircuit is monitoredby the PCM for a lowTP rotation angle (orvoltage) inputthrough thecomprehensivecomponent monitor

(CCM). If during keyON engine OFF orkey ON enginerunning the TProtation angle (orvoltage) changesbelow a minimumcalibrated limit, thetest fails.

q TP sensor not seatedproperly

q TP circuit open to PCMq VREF open to TP

sensorq TP circuit short to GNDq Damaged TP sensorq Damaged PCM

A TP PID (TP V PID) readless than 3.42% (0.17 voltkey ON engine OFF,continuous memory or keyON engine running indicata hard fault.


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P0123 - ThrottlePosition (TP)Circuit High Input

The TP sensorcircuit is monitoredby the PCM for ahigh TP rotationangle (or voltage)input through thecomprehensivecomponent monitor(CCM). If during keyON engine OFF orkey ON enginerunning the TProtation angle (orvoltage) changesabove maximumcalibrated limit, thetest fails.

q TP sensor not seatedproperly

q TP circuit short to PWRq VREF short to PWRq SIG RTN circuit open to

TP sensorq Damaged TP sensorq Damaged PCM

A TP PID (TP V PID) readgreater than 93% (4.65 voin key ON engine OFF,continuous memory or keyON engine running indicata hard fault.

P0125 -Insufficient

CoolantTemperature ForClosed Loop FuelControl

Indicates the ECTsensor has not

achieved therequired temperaturelevel to enter closedloop operatingconditions within aspecified amount oftime after startingengine.

q Insufficient warm uptime

q Low engine coolant levelq Leaking or stuck open

thermostatq Malfunctioning ECT

sensor

Compare ECT PID tothermostat specification w

vehicle is at operatingtemperature. Temperaturereadings should be simila

P0127 - Intake AirTemperature TooHigh

Indicates that IAT2sensor has detecteda potentialabnormality in theintercooler system.This condition willcause the boost fromthe supercharger tobe bypassed toavoid potentialengine damage.

q Blockage of heatexchangers

q Low fluid levelq Fluid leakageq Intercooler pump or

relay failureq Crossed intercooler

coolant lines

Monitor IAT2 PID. TypicalIAT2 temperature should greater than IAT1. Refer tSection 6, Reference Val

for ranges.

P0131 - HO2SSensor Circuit

Out of RangeLow Voltage(HO2S-11)

The HO2S sensor ismonitored for a

negative voltageknown ascharacteristic shiftdownward (CSD). Ifthe sensor is thoughtto be switching from0 volts to -1 voltsduring testing, thePCM will use thisinput and remain infuel control.

q Contaminated HO2S(water, fuel, etc)

q Crossed HO2Ssignal/signal returnwiring
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P0133 - HO2SSensor CircuitSlow Response(HO2S-11)

The HEGO Monitorchecks the HO2SSensor frequencyand amplitude. Ifduring testing thefrequency andamplitude were tofall below a

calibrated limit, thetest will fail.

q Contaminated HO2Ssensor.

q Exhaust leaks.q Shorted /open wiring.q Improper fueling.q MAF sensor.q Deteriorating HO2S

sensor.q

Inlet air leaks.

Access HO2S test resultsfrom the Generic OBD-IImenu to verify DTC.

P0135 - HO2SSensor CircuitMalfunction(HO2S-11)

During testing theHO2S Heaters arechecked foropens/shorts andexcessive currentdraw. The test failswhen current drawexceeds a calibratedlimit and/or an open

or short is detected.

q Short to VPWR inharness or HO2S.

q Water in harnessconnector.

q Open VPWR circuit.q Open GND circuit.q Low battery voltage.q Corrosion or poor

mating terminals and

wiringq Damaged HO2S heater.q Damaged PCM.

s wiring.s Damaged HO2S heates Damaged PCM.


The downstreamHO2S sensor(s) arecontinuouslychecked formaximum andminimum voltages.The test fails whenthe voltages fail tomeet the calibratedlimits.

q Pinched, shorted, andcorroded wiring andpins.

q Crossed sensor wires.q Exhaust leaks.q Contaminated or

damaged sensor.


See DTC P0135

P0151 - HO2SSensor CircuitOut of RangeLow Voltage

(HO2S-21)

See DTC P0131

P0153 - HO2SSensor CircuitSlow Response(HO2S-21)

See DTC P0133.

DTC Description Possible Causes Diagnostic Aid


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P0155 - HO2S SensorCircuit Malfunction(HO2S-21)

See DTC P0135

P0156 - HO2S SensorCircuit Malfunction(HO2S-22)

See DTC P0136

P0161 - HO2S SensorCircuit Malfunction

(HO2S-22)

See DTC P0135

P0171 - System toLean (Bank 1)

The Adaptive FuelStrategy continuouslymonitors fuel deliveryhardware. The testfails when theadaptive fuel tablesreach a richcalibrated limit.

P0172 - System toRich (Bank 1)

The Adaptive FuelStrategy continuously

monitors the fueldelivery hardware.The test fails whenthe adaptive fueltables reach a leancalibrated limit.

See Possible Causes for DTCP0171

P0174 - System toLean (Bank 2)

The Adaptive FuelStrategy continuouslymonitors the fueldelivery hardware.

The test fails whenthe adaptive fueltables reach a richcalibrated limit.

See Possible Causes for DTCP0171.

P0175 - System toRich (Bank 2)

The Adaptive FuelStrategy continuouslymonitors the fueldelivery hardware.The test fails whenthe adaptive fueltables reach a lean

calibrated limit.

See Possible Causes for DTCP0171.For lean and rich DTCs:

q Fuel systemq Excessive fuel pressure.q Leaking/contaminated fuel

injectors.q Leaking fuel pressure

regulator.q Low fuel pressure or

running out of fuel.q Vapor recovery system.q Induction system:

s Air leaks after theMAF.

s Vacuum Leaks.

A SHRTFT-1,2 Pvalue between -2to +35% and aLONGFT-1,2 PIDvalue between -3to +35% isacceptable. Read

beyond these valuindicate a failure.


7/55


s PCV system.s Improperly seated

engine oil dipstick.q EGR system:

s Leaking gasket.s Stuck EGR valve.s Leaking diaphragm

or EVR.q Base Engine:

s Oil overfill.s Cam timing.s Cylinder

compression.s Exhaust leaks before

or near the HO2Ss.

P0176 - Flexible Fuel(FF) Sensor CircuitMalfunction

The FF sensor inputsignal to PCM iscontinuouslymonitored. The test

fails when the signalfalls out of amaximum orminimum calibratedrange.

q Open or short in FF sensorVPWR circuit

q Open in battery ground toFF sensor circuit

q Open in FF sensor signalcircuit

q Short to ground in FFsensor signal circuit

q Fuel contaminationq Short to VPWR in FF

sensor battery groundcircuit

q Short to VPWR in FFsensor signal circuit

q Fuel separationq Damaged FF sensorq Damaged PCM

A flex fuel (FF) PIreading of 0 Hz wthe key ON andengine OFF or wi

engine at idleindicates a hard fa

P0180 - Engine FuelTemperature SensorA Circuit Low Input(EFT)

The comprehensivecomponent monitor(CCM) monitors theEFT sensor circuit tothe PCM for low andhigh voltage. Ifvoltage were to fallbelow or exceed a

calibrated limit andamount of timeduring testing, thetest will fail.

q Open or short in harness.q Low ambient temperature

operation.q Improper harness

connection.q Damaged EFT sensor.q Damaged PCM.

Verify EFT-PID vato determine openshort.


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P0181 - Engine FuelTemperature SensorA Circuit Range/Performance (EFT)

The comprehensivecomponent monitor(CCM) monitors theEFT Temperature foracceptable operatingtemperature. If duringtesting voltage wereto fall below orexceed a calibratedlimit, a calibratedamount of time thetest will fail.

q Open or short in harness.q Low ambient temperature




P0182 - Engine FuelTemperature SensorA Circuit Low Input(EFT)

The comprehensivecomponent monitor(CCM) monitors theEFT sensor circuit tothe PCM for lowvoltage. If voltagewere to fall below a

calibrated limit andamount of timeduring testing, thetest will fail.

q Short in harness.q VREF open or shorted.q Low ambient temperature



Verify EFT-PID anVREF values todetermine open oshort.

P0183 - Engine FuelTemperature SensorA Circuit High Input(EFT)

The comprehensivecomponent monitor(CCM) monitors theEFT sensor circuit tothe PCM for highvoltage. If voltagewere to exceed acalibrated limit and acalibrated amount oftime during testing,the test will fail.

q Open or short to PWR inharness.

q Damaged EFT sensor.q Improper harness

connection.q Damaged PCM.


P0186 - Engine FuelTemperature SensorB CircuitRange/Performance(EFT)

See DTC P0181.

P0187 - Engine Fuel

Temperature SensorB Circuit Low Input(EFT).

See DTC P0182.

P0188 - Engine FuelTemperature SensorB Circuit High Input(EFT)

See DTC P0183.


9/55


P0190 - Fuel RailPressure SensorCircuit Malfunction(FRP)

The comprehensivecomponent monitor(CCM) monitors theFRP sensor to thePCM for VREFvoltage. The test failswhen the VREFvoltage from thePCM drops to avoltage less than aminimum calibratedvalue.

q VREF open in harness.q VREF open in sensor.q VREF open in PCM.

Verify VREF voltabetween 4.0 and6.0V.

P0191 - Fuel RailPressure SensorCircuit Performance(FRP)

The comprehensivecomponent monitor(CCM) monitors theFRP pressure foracceptable fuelpressure. The testfails when the fuel

pressure falls belowor exceeds aminimum/maximumcalibrated value for acalibrated period oftime.

q High fuel pressure.q Low fuel pressure.q Damaged FRP sensor.q Excessive resistance in

circuit.q Low or no fuel.

A FRP PID valueduring KOER of 1kpa (20 psi) and 4kpa (60 psi) forgasoline or 586 k(85 psi) and 725 k(105 psi) for natur

gas vehicles (NGacceptable.

P0192 - Fuel RailPressure SensorCircuit Low Input(FRP)

The comprehensivecomponent monitor(CCM) monitors theFRP sensor circuit tothe PCM for lowvoltage. If voltagewere to fall below acalibrated limit andamount of timeduring testing, thetest will fail.

q FRP signal shorted to SIGRTN or PWR GND.

q FRP signal open (NG only)q Low fuel pressure (NG

only)q Damaged FRP sensor.q Damaged PCM.

A FRP PID valueduring KOER orKOEO less than 0volts for gasoline 0.5 volts for naturgas vehicles (NGwould indicate a hfault.

P0193 - Fuel RailPressure SensorCircuit High Input(FRP)

The comprehensivecomponent monitor(CCM) monitors theFRP sensor circuit to

the PCM for highvoltage. If voltagewere to fall below acalibrated limit and acalibrated amount oftime during testing,the test will fail.

q FRP signal shorted toVREF or VPWR.

q FRP signal open (gasolineonly)

q Low fuel pressure (NGonly)

q Damaged FRP sensor.q Damaged PCM.q High fuel pressure (caused

by damaged fuel pressureregulator) NG.

A FRP PID valueduring KOER orKOEO less than 0volts for gasoline

0.5 volts for naturgas vehicles (NGwould indicate a hfault.


10/55


P0217 - EngineCoolant Over-temperatureCondition

Indicates an engineoverheat conditionwas detected by thecylinder headtemperature(CHT)sensor. Thiscondition will causethe boost from the

supercharger to bebypassed to avoidpotential enginedamage.

q Engine cooling systemconcerns

q Low engine coolant levelq Base engine concerns

Monitor CHT PID overheat conditioTypical CHTtemperature shoube close to coolinsystem openingthermostatspecification.

P0230 - Fuel PumpPrimary CircuitMalfunction

NOTE: For naturalgas applications, thefollowing descriptionapplies to the fuelshutoff valve (FSV)circuit. The PCMmonitors the fuel

pump (FP) circuitoutput from the PCM.The test fails if: Withthe FP outputcommanded ON(grounded),excessive currentdraw is detected onthe FP circuit; or withthe FP outputcommanded OFF,

voltage is notdetected on the FPcircuit (the PCMexpects to detectVPWR voltagecoming through thefuel pump relay coilto the FP circuit).

q Open or shorted fuel pump(FP) circuit

q Open VPWR circuit to fuelpump relay

q Damaged fuel pump relayq Damaged PCM

q When the FPFPID reads YESfault is currentpresent.

q An open circuishort to grouncan only be

detected with fuel pumpcommanded O

q A short to powcan only bedetected with fuel pumpcommanded O

q During KOEO KOER self-testhe fuel pump

output commawill be cycled and OFF.

P0231 - Fuel PumpSecondary Circuit

Low

NOTE: For naturalgas applications, the

following descriptionapplies to the fuelshutoff valve monitor(FSVM) and the fuelshutoff valve power(FSV PWR) circuits.The PCM monitorsthe fuel pumpmonitor (FPM) circuit.The test fails if thePCM commands the

q Open B+ circuit to the fuelpump relay

q Open FP PWR circuitbetween the fuel pumprelay and its connection tothe FPM circuit

q Damaged fuel pump relayq Damaged PCM (engine will

start)q For 4.6L Mustang, open FP

PWR circuit from low speedfuel pump relay, throughresistor to FPM splice

During KOEO seltest, the PCM will

command the fuepump ON so this can be performed


11/55


fuel pump ON andB+ voltage is notdetected on the FPMcircuit.

(engine will start)q For 5.4L SC Lightning,

damaged IFS switch, IFSswitch relay, or concernwith related circuits.

P0232 - Fuel PumpSecondary CircuitHigh

NOTE: For naturalgas applications, thefollowing description

applies to the fuelshutoff valve monitor(FSVM) and the fuelshutoff valve power(FSV PWR) circuits.The PCM monitorsthe fuel pumpmonitor (FPM) circuit.This test fails whenthe PCM detectsvoltage on the FPM

circuit while the fuelpump is commandedOFF. The FPM circuitis wired to a pull-upvoltage inside thePCM. The FPMcircuit will go high if,with the key ON andthe fuel pumpcommanded OFF,the FPM/FP PWR

circuit loses its pathto ground through thefuel pump. The FPMcircuit will also gohigh if the FPM/FPPWR circuit isshorted to power.

q Inertia fuel shutoff (IFS)switch not reset orelectrically open

qOpen circuit between thefuel pump and the FPMconnection to the FP PWRcircuit

q Poor fuel pump groundq Fuel pump electrically openq Fuel pump secondary

circuits short to powerq Fuel pump relay contacts

always closedq Open FPM circuit between

PCM and connection to FPPWR circuit

q Damaged low speed fuelpump relay or concern withrelated circuits (ifequipped).

q Damaged PCM

P0232 can be setthe fuel pump circis activated when

PCM expected thcircuit to be off (i.fuel system test oprime procedure)

q EDIS systemfailure

q High speed fupump failure

q Engine speedexceeds

calibratedthreshold

q Transmissionelectronicpressure contr(EPC) solenoifailure

q Cylinder headtemperature(CHT) exceedcalibrated limit

P0234 - SuperchargerOverboost Condition

The PCM disables(bypasses) thesupercharger boost

and sets a diagnostictrouble code (DTC) tokeep from damagingthe powertrain(engine ortransmission) duringpotential harmfuloperating conditions.

q Brake torque (brake on andthrottle at wide open)

q Transmission oil

temperature (TOT)exceeds calibratedthreshold

q Engine over temperatureq Ignition misfire exceeds

calibrated thresholdq Knock sensor (KS) failure

or knock detectedq Low speed fuel pump relay

not switching

Check for otherdiagnostic troublecodes accompany

the P0234 or checappropriate andavailable PIDsrelated to abovepossible causes.


12/55


P0243 - Supercharger(Boost) BypassSolenoid CircuitMalfunction

The PCM monitorsthe supercharger(boost) bypass (SCB)solenoid circuit for anelectrical failure. Thetest fails when thesignal moves outsidethe minimum or

maximum allowablecalibratedparameters for aspecified SCBsolenoid duty cycle(100% or 0%) byPCM command.

q VPWR circuit open to SCBsolenoid

q SCB solenoid circuitshorted to PWR GND orCHASSIS GND

q Damaged SCB solenoidq SCB solenoid circuit openq SCB solenoid circuit

shorted to VPWRq Damaged PCM

Disconnect SCBsolenoid. Connectest lamp to SCBsolenoid harnessconnector. CycleSCB driver in PCMby Output TestMode. Test lamp

cycle on and off -SCB solenoid issuspect. Test lamalways on - SCBsignal short inharness or PCM.Test always off -SCB signal or VPopen in harness oPCM.

P0298 - Engine Oil

Over TemperatureCondition

Indicates the Engine

Oil TemperatureProtection strategy inthe PCM has beenactivated. This willtemporarily prohibithigh engine speedoperation bydisabling injectors,therefore reducingthe risk of enginedamage from high

engine oiltemperature. Note:On engines whichare equipped with anoil temperaturesensor, the PCMreads oil temperatureto determine if it isexcessive. When anoil temperature

sensor is not present,the PCM uses an oilalgorithm to inferactual temperature.Engine shutdownstrategy function isthe same on vehicleswith and without oiltemperature sensors.

q Very high engine rpm forextended period of time.

q Over-heating condition.q Malfunction EOT sensor or

circuit (vehicles w/EOTsensor).

q Base engine concerns.

Engine operating

high rpm range, dto improper gearselection. May caLack/Loss of Powor Surge customeconcern.


13/55


DTC Description Possible Causes Diagnostic Aide

P0300 - Random Misfire The randommisfire DTCindicates multiplecylinders aremisfiring or thePCM cannot

identify whichcylinder ismisfiring.

q Camshaft position sensor(CMP)

q Low fuel: less than 1/8 tankq Stuck open EGR valve

P0301 through P0310 -Misfire DetectionMonitor

The misfiredetection monitoris designed tomonitor enginemisfire andidentify thespecific cylinderin which the

misfire hasoccurred. Misfireis defined as lackof combustion ina cylinder due toabsence of spark,poor fuelmetering, poorcompression, orany other cause.

q Ignition systemq Fuel injectorsq Running out of fuelq EVAP canister purge valveq Fuel pressureq Evaporative emission

systemq Base engine

The MIL will blinkonce per secondwhen a misfire isdetected severeenough to causecatalyst damage. Ithe MIL is on steadstate, due to a mis

this will indicate ththreshold foremissions wasexceeded and cauthe vehicle to fail ainspection andmaintenance tailpitest.

P0320 - Ignition EngineSpeed Input CircuitMalfunction

The ignitionengine speedsensor inputsignal to PCM iscontinuouslymonitored. Thetest fails whenthe signalindicates that twosuccessiveerratic profile

ignition pickup(PIP) pulses haveoccurred.

q Loose wires/ connectors.q Arcing secondary ignition

components (coil, wires andplugs)

q On board transmitter (2-wayradio)

The DTC indicatesthat two successiverratic PIP pulsesoccurred.

P0325 - Knock Sensor 1Circuit Malfunction(Bank 1)


14/55


P0326 - Knock Sensor 1Circuit Range/Performance (Bank 1)

The knock sensordetects vibrationsupon increaseand decrease inengine rpm. Theknock sensorgenerates avoltage based on

this vibration.Should thisvoltage gooutside acalibrated level aDTC will set.

q Knock sensor circuit short toGND

q Knock sensor circuit short toPWR

q Knock sensor circuit openq Damaged knock sensorq Damaged PCM

A knock sensorvoltage greater tha0.5V with the key Oand engine OFFindicates a hard fa

P0330 - Knock Sensor 2Circuit Malfunction(Bank 2)

P0331 - Knock Sensor 2Circuit

Range/performance(Bank 2)

The knock sensordetects vibration

upon increaseand decrease inengine rpm. Theknock sensorgenerates avoltage based onthis vibration.Should thisvoltage gooutside acalibrated level aDTC will set.

q Knock sensor circuit short toGND

q Knock sensor circuit short toPWR

q Damaged knock sensorq Damaged PCMq Knock sensor circuit open

A knock sensorvoltage greater tha

0.5V with the key Oand engine OFFindicates a hard fa

P0340 - CamshaftPosition (CMP) SensorCircuit Malfunction

The test failswhen the PCMcan no longerdetect the signalfrom the CMPsensor.

q CMP circuit openq CMP circuit short to GNDq CMP circuit short to PWRq SIG RTN open (VR sensor)q CMP GND open (Hall effect

sensor)q CMP misinstalled (Hall

effect sensor)q Damaged CMP sensor

shieldingq Damaged CMP sensorq Damaged PCM

Harness routing,harness alterationsimproper shieldingelectrical interferenfrom other impropefunctioning systemmay have intermittimpact on the CMPsignal.


15/55


P0350 - Ignition Coil(Undetermined)Primary/ SecondaryCircuit Malfunction

Each ignitionprimary circuit iscontinuouslymonitored. Thetest fails whenthe PCM doesnot receive avalid IDM pulsesignal from theignition module(integrated inPCM).

q Open or short in IgnitionSTART/RUN circuit

q Open coil driver circuitq Coil driver circuit shorted to

groundq Damaged coilq Damaged PCMq Coil driver circuit shorted to

VPWR

P0351 Through P0360 -Ignition Coil A throughJ Primary/ SecondaryCircuit Malfunction

Each ignitionprimary circuit iscontinuouslymonitored. Thetest fails whenthe PCM doesnot receive a

valid IDM pulsesignal from theignition module(integrated inPCM).

q Open or short in IgnitionSTART/RUN circuit

q Open coil driver circuit inharness

q Coil driver circuit shorted toground

q Damaged coilq Damaged PCMq Coil driver circuit shorted to

PWR

P0401 - EGR FlowInsufficient Detected

The EGR systemis monitoredduring steadystate drivingconditions whilethe EGR iscommanded on.The test failswhen the signalfrom the DPFEGR sensorindicates thatEGR flow is lessthan the desiredminimum.

q Vacuum supplyq EGR valve stuck closedq EGR valve leaks vacuumq EGR flow path restrictedq EGRVR circuit shorted to

PWRq VREF open to DPF EGR

sensorq DPF EGR sensor

downstream hose off orplugged

q EGRVR circuit open to PCMq VPWR open to EGRVR

solenoidq DPF EGR sensor hoses

both offq

DPF EGR sensor hosesreversedq Damaged EGR orifice tubeq Damaged EGRVR solenoidq Damaged PCM

Perform KOER setest and look for DP1408 as anindication of a hardfault. If P1408 is nopresent, look forcontamination,restrictions, leaks, intermittents.


16/55


P0402 - EGR FlowExcessive Detected

The EGR systemis monitored forundesired EGRflow during idle.The EGR monitorlooks at the DPFEGR signal atidle and

compares it tothe stored signalmeasured duringkey ON andengine OFF. Thetest fails whenthe signal at idleis greater than atkey ON engineOFF by acalibrated

amount.

q EGR valve stuck openq Plugged EGR vacuum

regulator solenoid ventq Plugged EGR tubeq Slow responding DPF EGR

sensorq Damaged DPF EGR sensorq Improper vacuum hose

connectionq Plugged vacuum hosesq EGRVR circuit shorted to

groundq Damaged EGR vacuum

regulator solenoidq Damaged PCM

A DPFEGR PIDreading that is greaat idle than during ON and engine OFby 0.5 volt or a rouengine idle, mayindicate a hard fau

P0411 - Secondary AirInjection (AIR) systemupstream flow

See DTC P1411

P0412 - Secondary AirInjection System (AIR)circuit malfunction

The PCMattempts tocontrol when airis injected in theexhaust. TheDTC indicates aSecondary Airinjection systemAIR circuit fault.

q AIR circuit openq AIR bypass solenoid faultq Damaged PCMq AIR circuit short to powerq Solid state relay faultq Damaged AIR pump

The AIR circuit isnormally held highthrough the AIRbypass solenoid aSSR when the outdriver is off.Therefore, a low Acircuit indicates adriver is always onand a high circuitindicates an open the PCM.

P0420 - CatalystSystem EfficiencyBelow Threshold (Bank1)

Indicates Bank 1catalyst systemefficiency isbelow theacceptable

threshold

q Use of leaded fuelq Damaged HO2Sq Malfunctioning ECTq High fuel pressureq Damaged exhaust manifoldq Damaged catalytic converterq Oil contaminationq Cylinder misfiringq Downstream HO2S wires

improperly connectedq Damaged exhaust system

pipeq Damaged muffler/tailpipe

assemblyq Retarded spark timing

s Compare HO2Supstream &downstream swrate. Under norclosed loop fue

conditions, highefficiency catalyhave oxygenstorage whichmakes theswitchingfrequency of thdownstream HOquite slowcompared to thupstream HO2S


17/55


As catalystefficiencydeteriorates, itsability to storeoxygen declineand thedownstream HOsignal begins toswitch morerapidlyapproaching thswitching rate othe upstreamHO2S. Oncebeyond anacceptable limithe DTC is set.

P0430 - CatalystSystem Efficiency

Below Threshold (Bank2)

Indicates Bank 2catalyst system

efficiency isbelow theacceptablethreshold.

q Use of leaded fuelq Damaged HO2Sq Malfunctioning ECTq High fuel pressureq Damaged exhaust manifoldq Damaged catalytic converterq Oil contaminationq Cylinder misfiringq Downstream HO2S wires

improperly connectedq Damaged exhaust system

pipeq Damaged muffler/ tailpipe

assemblyq Retarded spark timing

Compare HO2Supstream &

downstream switchrate. Under normaclosed loop fuelconditions, highefficiency catalystshave oxygen storawhich makes theswitching frequencthe downstreamHO2S quite slowcompared to the

upstream HO2S. Acatalyst efficiencydeteriorates, its abto store oxygendeclines and thedownstream HO2Ssignal begins to swmore rapidlyapproaching theswitching rate of thupstream HO2S.Once beyond anacceptable limit theDTC is set.


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P0442 - EVAP ControlSystem Leak Detected(Small Leak)

The PCMmonitors thecomplete EVAPcontrol system forpresence of asmall fuel vaporleak. The systemfailure occurswhen a fuel vaporleak from anopening as smallas 0.10 cm (0.04inch) is detectedby the EVAPrunning lossmonitor test.

q After-market EVAPhardware (such as fuel fillercap) non-conforming torequired specifications

q Small holes or cuts in fuelvapor hoses/tubes

q Canister vent solenoid stayspartially open on closedcommand

q Damaged, cross-threadedor loosely installed fuel fillercap

q Loose fuel vapor hose/tubeconnections to EVAPsystem components

q EVAP system componentseals leaking (EVAPcanister purge valve, fueltank pressure sensor,

canister vent solenoid, fuelvapor control valve tubeassembly or fuel vapor ventvalve assembly)

P0443 - EVAP ControlSystem Canister PurgeValve CircuitMalfunction

The PCMmonitors theEVAP canisterpurge valvecircuit for anelectrical failure.The test fails

when the signalmoves outsidethe minimum ormaximumallowablecalibratedparameters for aspecified purgeduty cycle byPCM command.

q VPWR circuit openq EVAP canister purge valve

circuit shorted to GNDq Damaged EVAP canister

purge valveq EVAP canister purge valve

circuit openq EVAP canister purge valve

circuit shorted to VPWRq Damaged PCM

Monitor EVAPPDCPID and voltagebetween EVAPcanister valve signand PWR GND inoutput test mode wkey ON engine OF

(or in key ON engiRUNNING mode).EVAPPDC PID at and voltage less th1.0 volts (orEVAPPDC PID at100% and voltageless than 0.5 volts)indicates a hard fa

P0451 - FTP SensorCircuit Noisy The fuel tankpressurechanges greaterthan 14 inches ofH2O in 0.10seconds.

qIntermittent open or short inthe FTP sensor or the FTPsensor signal

Monitor the FTP Pand does it changefrom above 15 inchof H2O to below aminus (-) 15 inchesH2O often in 1.0minute.


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P0452 - FTP SensorCircuit Low VoltageDetected

The PCMmonitors theEVAP controlsystem FTPsensor inputsignal to thePCM. The testfails when the

signal averagedrops below aminimumallowablecalibratedparameter.

q Contamination internal toFTP sensor connector

q Damaged PCMq FTP circuit shorted to GND

or SIG RTNq Damaged FTP sensor

FTP V PID readingless than 0.22 voltwith key ON andengine OFF or durany engine operatimode indicates a hfault.

P0453 - FTP SensorCircuit High VoltageDetected

The PCMmonitors theEVAP controlsystem FTPsensor input

signal to thePCM. The testfails when thesignal average

jumps above aminimumallowablecalibratedparameter.

q FTP circuit openq VREF shorted to VPWRq Damaged PCMq FTP circuit shorted to VREF

or VPWR

q SIG RTN circuit openq Damaged FTP sensor

FTP V PID readinggreater than 4.50 vwith key ON andengine OFF or durany engine operati

mode indicates a hfault.

P0455 - EVAP ControlSystem Leak Detected(No Purge Flow orLarge Leak)

The PCMmonitors thecomplete EVAPcontrol system forno purge flow,the presence of alarge fuel vaporleak or multiplesmall fuel vaporleaks. Thesystem failureoccurs when no

purge flow(attributed to fuelvapor blockagesor restrictions), alarge fuel vaporleak or multiplefuel vapor leaksare detected bythe EVAPrunning lossmonitor test with

q After-market EVAPhardware (such as fuel fillercap) non-conforming torequired specifications

q Disconnected or crackedfuel EVAP canister tube,EVAP canister purge outlettube or EVAP return tube

q EVAP canister purge valvestuck closed

q Damaged EVAP canisterq Damaged or missing fuel

filler capq Insufficient fuel filler cap

installationq Loose fuel vapor hose/tube

connections to EVAPsystem components

q Blockages or restrictions infuel vapor hoses/tubes(items also listed underdisconnections or cracks)

q Fuel vapor control valve

Check for audiblevacuum noise orsignificant fuel odothe enginecompartment or nethe EVAP canisterand fuel tank.


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the enginerunning (but notat idle).

tube assembly or fuel vaporvent valve assemblyblocked

q Canister vent (CV) solenoidstuck open

q Mechanically inoperativefuel tank pressure (FTP)sensor

P0457 - EVAP ControlSystem Leak Detected(Fuel Filler CapLoose/Off)

A fuel tankpressure changegreater than aminus(-) 7 inchesof H2O in 30seconds hasoccurred afterrefueling; or thereis excessivepurge (fuel vapor)flow greater than

0.06 pounds perminute.

qFuel filler cap not installedon refueling (storingcontinuous memory DTC).

q Fuel filler cap missing, looseor cross-threaded.

Check for missing filler cap or integritthe cap. If OK, cleacontinuous memorDTCs and reinitiateEVAP EmissionRunning Loss MonDrive Cycle.

P0460 - Fuel LevelSensor CircuitMalfunction

The PCMmonitors the fuellevel input (FLI)circuit forelectrical failure.The test failswhen the signalmoves outsidethe minimum or

maximumallowablecalibratedparameters for aspecified fuel fillpercentage in thefuel tank.

q Empty fuel tankq Fuel pump (FP) module

stuck openq Incorrectly installed fuel

gaugeq Damaged instrument clusterq CASE GND circuit openq FLI shorted to VPWRq Damaged PCMq Overfilled fuel tankq Fuel pump (FP) module

stuck closedq Damaged fuel gaugeq FLI circuit openq FLI circuit shorted to CASE

GND or PWR GNDq CSE GND shorted to VPWR

Monitor FLI PID anFLI V PID in key Oengine RUNNING.PID at 25% fill (witnone matching fuegauge) and FLI V less than 0.90 voltfor FLI PID at 75%(with none matchin

fuel gauge) and FLPID greater than 2volts] indicates a hfault.

P0500 - Vehicle SpeedSensor (VSS)

Malfunction

Indicates thepowertrain

control module(PCM) detectedan error in thevehicle speedinformation.Vehicle speeddata is receivedfrom either thevehicle speedsensor (VSS),transfer case

q Open in VSS+/VSS-harness circuit.

q Open in TCSS signal orTCSS signal return harnesscircuit.

q Short to GND in VSSharness circuit.

q Short to GND in TCSSharness circuit.

q Short to PWR in VSSharness circuit.

q Short to PWR in TCSSharness circuit.

Diagnostic Aids: -Monitor VSS PID

while driving vehicThis DTC is set whthe PCM detects asudden loss of VSsignal over a periotime. If vehicle spedata is lost, checksource of wherevehicle speed signoriginates. Note TCdoes not have a P


21/55


speed sensor(TCSS), anti-lockbrake system(ABS) controlmodule, genericelectronic module(GEM), or centraltimer module(CTM). If theengine rpm isabove the torqueconverter stallspeed (automatictransmission) andengine load ishigh, it can beinferred that thevehicle must bemoving. If there is

insufficientvehicle speeddata input, amalfunction isindicated and aDTC is set. Onmost vehicleapplications themalfunctionindicator lamp(MIL) will be

triggered whenthis DTC is set.

q Open or short in the vehiclespeed circuit(s) (VSC)between the PCM andappropriate control module.

q Damaged VSS or TCSS.q Damaged wheel speed

sensors.q Damaged wheel speed

sensor harness circuits.q Damage in module(s)

connected to VSC/VSScircuit.

q Damage drive mechanismfor VSS or TCSS.

circuitry frequencymust be checked fsudden loss of sensignal.

P0501 - Vehicle SpeedSensor (VSS) Range/Performance

Indicates thepowertraincontrol module(PCM) detectedan error in thevehicle speedinformation. ThisDTC is set thesame way asP0500, howeverthe malfunctionindicator lamp(MIL) is nottriggered.

q Refer to possible causes forP0500.

Refer to diagnosticaids for P0500.


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P0503 - Vehicle SpeedSensor (VSS)Intermittent

Indicates poor ornoisy VSSperformance.Vehicle speeddata is receivedfrom either thevehicle speedsensor (VSS),transfer casespeed sensor(TCSS), anti-lockbrake system(ABS) controlmodule, genericelectronic module(GEM), or centraltimer module(CTM).

q Noisy VSS/TCSS inputsignal from RadioFrequencyInterference/Electro-Magnetic Interference(RFI/EMI) external sourcessuch as ignition componentsor charging circuit.

q Damaged VSS or drivengears.

q Damaged TCSS.q Damaged wiring harness or

connectors.q Malfunction in module(s) or

circuit connected toVSS/TCSS circuit.

q After market add-on.

Monitor VSS PIDwhile driving vehiccheck for intermittevehicle speedindication. Verifyignition and chargisystem arefunctioning.

P0503 - Vehicle Speed

Sensor (VSS)Intermittent

Indicates poor or

noisy VSSperformance.

q Noisy VSS input signal fromRadio FrequencyInterference/ Electro-Magnetic Interference(RFI/EMI) external sourcessuch as ignition componentsor charging circuit.

q Damaged VSS or drivengears.

q Damaged wiring harness orconnectors.

q Malfunction in module(s) orcircuit connected to VSScircuit.

Verify ignition and

charging system afunctioning correctCheck for good VS) to ground.

P0505 - Idle Air ControlSystem Malfunction

The PCMattempts tocontrol enginespeed duringKOER self-test.The test failswhen the desiredrpm could not be

reached orcontrolled duringthe self-test.

q IAC circuit openq VPWR to IAC solenoid openq IAC circuit shorted to PWRq Air inlet is pluggedq Damaged IAC valveq Damaged PCM

The IAC solenoidresistance is from 13 ohms.


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P0552 - Power SteeringPressure (PSP) SensorCircuit Malfunction

The PSP sensorinput signal to thePCM iscontinuouslymonitored.Thetest fails whenthe signal is openor shorted to

ground.

q PSP sensor damagedq SIG RTN circuit open or

shortedq VREF circuit open or

shortedq PSP sensor signal circuit

open or shortedq Damaged PCM

The DTC indicatesPSP sensor circuitopen or shorted toground.


P0553 - PowerSteeringPressure(PSP) SensorCircuitMalfunction

The PSP sensorinput signal to PCMis continuouslymonitored. The testfails when the signalis shorted to power.

q PSP sensor damagedq SIG RTN circuit shorted to

powerq VREF circuit shorted to powerq PSP sensor signal circuit

shorted to powerq Damaged PCM

The code indicates thPSP sensor circuit isshorted to power.

P0602 -ControlModuleProgrammingError

This DiagnosticTrouble Code (DTC)indicatesprogramming errorwithin Vehicle IDblock (VID).

q VID data corrupted by the scantool during VID reprogramming

Using the scan tool,reprogram the VID blIf PCM does not allowreprogramming of theVID block, reflashingPCM will be required

P0603 -PowertrainControl

Module KAMTest Error

Indicates the PCMhas experienced aninternal memory

fault. However thereare external itemsthat can cause thisDTC.

q Reprogrammingq Battery terminal corrosionq KAPWR to PCM interrupt/openq Loose battery connectionq Damaged PCM

If KAPWR is interruptto the PCM because battery or PCM

disconnect, DTC cangenerated on the firstpower-up.

P0605 - PCMRead OnlyMemory(ROM) error

The PCM ROM hasbeen corrupted.

q An attempt was made to changethe calibration

q Module programming errorq Physically damaged PCM

s Reprogram or updcalibration

s Reprogram VID b(use as built data)

s Check for otherDTC's or drivesymptoms for furt

action


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P0703 - BrakeSwitch CircuitInputMalfunction

Indicates PCM didnot receive a brakepedal position (BPP)input.

q Open or short in BPP circuitq Open or short in stoplamp

circuitsq Damaged PCMq Malfunction in module(s)

connected to BPP circuit. (RearElectronic Module [REM]Windstar and LS6/LS8 orLighting Control Module (LCM)Continental and Town Car.

q Damaged brake switchq Misadjusted brake switch

Check for properfunction of stoplampsFollow correct Self-Teprocedures, refer toSection 2of Quick Te

P0704 - ClutchPedal PositionSwitchMalfunction

When the clutchpedal is depressedthe voltage goes tolow. If the PCM doesnot see this changefrom high to low theDTC is set.

q CPP circuit short to PWRq Damaged CPP switchq CPP circuit open in the SIGRTNq Damaged PCM

When depressing theCPP switch the voltagshould cycle from 5.0down.

P0720 -Insufficientinput fromOutput ShaftSpeed sensor

The output shaftspeed sensor inputsa signal to the PCM,based on the speedof the output shaft ofthe transmission.The PCM comparesthis signal with thesignal of the VSS orTCSS anddetermines correcttire size and axlegear ratio.

q OSS sensor circuit short to GNDq OSS sensor circuit short to PWRq OSS sensor circuit openq Damaged OSS sensorq Damaged PCM

Verify sensor signaloutput varies with vehspeed.

P0721 - Noiseinterferenceon OutputShaft Speedsensor signal

The output shaftspeed sensor signalis very sensitive tonoise. This noisedistorts the input tothe PCM.

q Wiring misroutedq After market add-onq Wiring damagedq Wiring insulation wear

s Check routing ofharness.

s Check wiring andconnector fordamage.

P0722 - Nosignal from

Output ShaftSpeed sensor

The output shaftspeed sensor failed

to provide a signal tothe PCM upon initialmovement ofvehicle.

q Damaged OSS connectorq Damaged OSS sensor, or not

installed properlyq Harness intermittently shorted or

open
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P0723 -Output ShaftSpeed sensorcircuitintermittentfailure

The output shaftspeed sensor signalto the PCM isirregular orinterrupted.

q Harness connector not properlyseated

q Harness intermittently shorted,or open

q Harness connector damagedq OSS sensor damaged, or not

installed properly

s Verify harness anconnector integrity

s Verify OSS sensoproper installation

P0812 -

ReverseSwitch (RS)input circuitmalfunction

The DTC indicates

that the voltage ishigh when it shouldbe low.

q Transmission shift not indicating

neutral while in KOEO Self-Testq RS circuit short to PWRq Damaged reverse switchq RS circuit open or short to

SIGRTNq Damaged PCM

Check RS PID while

exercising shift lever and out of reverse.

P1000 -MonitorTesting NotComplete

The on boarddiagnostic II (OBDII) monitors areperformed duringthe OBD II Drive

Cycle. The DTC willbe stored incontinuous memoryif any of the OBD IImonitors do notcomplete.

q Vehicle is new from the factoryq Battery or PCM had recently

been disconnectedq An OBD II monitor failure had

occurred before completion of an

OBD II drive cycleq PCM DTCs have recently been

cleared with a scan toolq PTO circuit is shorted to VPWR

or B+ or PTO is on during testing

The DTC does not neto be cleared from thePCM except to pass inspection/maintenantest.

P1001 - KOERNot Able ToComplete,KOERAborted

This Non-MIL(MalfunctionIndicator Lamp)code will be setwhen Key OnEngine Running(KOER) Self-Testdoes not complete inthe time intended.

q Incorrect Self-Test Procedure.q Unexpected response from Self-

Test monitors.q rpm out of specification.

Rerun Self-Test followQT1 in Section 3,

Symptom Charts, ST1: PCM Quick Test.

P1100 - MassAir Flow(MAF) SensorIntermittent

The MAF sensorcircuit is monitoredby the PCM forsudden voltage (orair flow) inputchange through the

comprehensivecomponent monitor(CCM). If during thelast 40 warm-upcycles in key ONengine running thePCM detects avoltage (or air flow)change beyond theminimum ormaximum calibrated

q Poor continuity through the MAFsensor connectors

q Poor continuity through the MAFsensor harness

q Intermittent open or short insidethe MAF sensor.

While accessing theMAF V PID on the sctool, lightly tap on theMAF sensor or wigglethe MAF sensorconnector and harnes

If the MAF V PIDsuddenly changes be0.23 volt or above 4.6volts, an intermittent fis indicated.
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limit, a continuousmemory diagnostictrouble code (DTC)is stored.

P1101 - MassAir Flow(MAF) SensorOut of Self-

Test Range

The MAF sensorcircuit is monitoredby the PCM for anout of range air flow

(or voltage) input. Ifduring key ONengine OFF the airflow (or voltage)reading is greaterthan (grams/secondequivalent chart inpinpoint test DC [0.27 volt]), the testfails. Likewise, ifduring key ON

engine running anair flow (or voltage)reading is not within(gram/secondequivalent chart inpinpoint test DC[0.46 volt to 2.44volts]), the test fails.

q Low battery chargeq MAF sensor partially connectedq MAF sensor contaminationq PWR GND open to MAF sensorq

MAF RTN circuit open to PCMq Damaged MAF sensorq Damaged PCM

A MAF V PID readinggreater than 0.27 volt(KOEO) or a MAF V Preading outside the 0

volt to 2.44 volts rang(KOER) indicates a hfault.

P1109 - IntakeAirTemperature 2SensorIntermittent

Indicates IAT2circuit becameintermittently openor shorted whileengine was running.

q Damaged harnessq Damaged sensorq Damaged harness connectorq Damaged PCM

Monitor IAT2 on scantool, look for suddenchanges in reading wharness is wiggled orsensor is tapped.

P1112 - IntakeAirTemperature(IAT) SensorIntermittent

Indicates IAT sensorsignal wasintermittent duringthe comprehensivecomponent monitor.


Monitor IAT on scan tlook for sudden chanin reading when harnis wiggled or sensor itapped.

P1114 - IntakeAirTemperature 2

Circuit LowInput

Indicates the sensorsignal is less thanSelf-Test minimum.

The IAT2 sensorminimum is 0.2 voltsor 121C (250F).

q Grounded circuit in harnessq Improper harness connectionq Damaged sensorq Damaged PCM

Monitor IAT2 PID.Typical IAT2temperature should b

greater than IAT1. Reto Section 6, Referen

Values for ranges.

P1115 - IntakeAirTemperature 2Circuit HighInput

Indicates the sensorsignal is greaterthan Self-Testmaximum. The IAT2sensor maximum is4.6 volts or -50C (-46F).

q Open circuit in harnessq Sensor signal short to powerq Damaged PCMq Improper harness connectionq Damaged sensor

Monitor IAT2 PID.Typical IAT2temperature should bgreater than IAT1. Reto Section 6, Referen

Values for ranges.
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P1116 -EngineCoolantTemperature(ECT) SensorOut of Self-Test Range

Indicates the ECTsensor is out of Self-Test range. Correctrange is 0.3 to 3.7volts.

q Overheating conditionq Malfunctioning thermostatq Damaged ECT sensorq Low engine coolantq Damaged harness connectorq Damaged PCM

Engine coolanttemperature must begreater than 10C (50F) to pass the KOEOSelf-Test and greaterthan 82 C (180F) topass the KOER Self-Test.

P1117 -EngineCoolantTemperature(ECT) SensorIntermittent

Indicates ECT circuitbecameintermittently openor shorted whileengine was running.

qDamaged harness

q Damaged sensorq Damaged PCMq Damaged harness connectorq Low engine coolant

sMonitor ECT on stool, look for suddchanges in readinwhen harness iswiggled or sensortapped.

q TP circuitintermittentopen

q Damaged Tsensor

q Damaged PP1120 -ThrottlePosition (TP)Sensor Out ofRange Low(RATCH tooLow)

The TP sensorcircuit is monitoredby the PCM for alow TP rotationangle (or voltage)input below theclosed throttleposition through thecomprehensivecomponent monitor(CCM). If during keyON engine OFF orkey ON enginerunning the TProtation angle (orvoltage) remainswithin the calibratedself-test range butfalls between 3.42and 9.85% (0.17

and 0.49 volt), thetest fails.

q TP circuit with frayed wiresq Corrosion on TP circuit

connectorsq VREF open to TP sensorq VREF short to SIG RTNq TP sensor loose pins

A TP PID (TP V PID)between 3.42 and 9.8(0.17 and 0.49 volt) inkey ON engine OFF,continuous memory okey ON engine runninindicates a hard fault


28/55


P1121 -ThrottlePosition (TP)SensorInconsistentwith MAFSensor

The PCM monitors avehicle operationrationality check bycomparing sensedthrottle position tomass air flowreadings. If duringkey ON engine

running self-test thecomparison of theTP sensor and MAFsensor readings arenot consistent withcalibrated loadvalues, the test failsand a diagnostictrouble code isstored in continuousmemory.

q Air leak between MAF sensorand throttle body

q TP sensor not seated properlyq Damaged TP sensorq Damaged MAF sensor

Drive vehicle andexercise throttle and sensor in all gears. APID (TP V PID) less t4.82 % (0.24 volt) witLOAD PID greater th55% or a TP V PIDgreater than 49.05%

(2.44 volts) with a LOPID less than 30%indicates a hard fault

P1124 -ThrottlePosition (TP)Sensor Out ofSelf-TestRange

The TP sensorcircuit is monitoredby the PCM for anout of range TProtation angle (orvoltage) input. Ifduring key ONengine OFF or keyON engine runningthe TP rotationangle (or voltage)

reading is less than13.27% (0.66 volt)or greater than23.52% (1.17 volts),the test fails.

q Binding or bent throttle linkageq TP sensor not seated properlyq Throttle plate below closed

throttle positionq Throttle plate/screw misadjustedq Damaged TP sensorq Damaged PCM

A TP PID (TP V PID)reading not between13.27 and 23.52% (0and 1.17 volts) in keyON engine OFF or keON engine runningindicates a hard fault

P1125 -ThrottlePosition (TP)SensorIntermittent

The TP sensorcircuit is monitoredby the PCM forsudden TP rotationangle (or voltage)

input changethrough thecomprehensivecomponent monitor(CCM). If during thelast 80 warm-upcycles in key ONengine running thePCM detects a TProtation angle (orvoltage) changes

q Poor continuity through the TPsensor connectors

q Poor continuity through the TPharness

q Intermittent open or short insidethe TP sensor

While accessing the TV PID on the scan toolightly tap on the TPsensor or wiggle the Tsensor connector and

harness. If the TP V Psuddenly changes be0.49 volt or above 4.6volts, an intermittent fis indicated.


29/55


beyond theminimum ormaximum calibratedlimit, a continuousdiagnostic troublecode (DTC) isstored.

P1127 -

Exhaust NotWarmEnough,DownstreamSensor NotTested

The HEGO monitor

uses an exhausttemperature modelto determine whenthe HO2S heatersare cycled ON. Thetest fails when theinferred exhausttemperature isbelow a minimumcalibrated value.

q Engine not operating long

enough prior to performingKOER self-test.q Exhaust system too cool.

Monitor HO2S Heate

PIDs to determine theON/OFF state. DTCP1127 will be presenthe exhaust is not hot

P1128 -

UpstreamOxygenSensorsSwapped fromBank to Bank(HO2S-11-21)

The HEGO monitor

checks anddetermines if theHO2S signalresponse for a fuelshift corresponds tothe correct enginebank. The test failswhen a responsefrom the HO2S(s)being tested is notindicated.

q Crossed HO2S harnessconnectors (upstream).

q Crossed HO2S wiring at theharness connectors (upstream).

q Crossed HO2S wiring at the 104-pin harness connectors(upstream).

P1129 -DownstreamOxygenSensorsSwapped fromBank to Bank(HO2S-12-22)

The HEGO monitorchecks anddetermines if theHO2S signalresponse for a fuelshift corresponds tothe correct enginebank. The test failswhen a responsefrom the HO2S(s)

being tested is notindicated.

q Crossed HO2S harnessconnectors (downstream).

q Crossed HO2S wiring at theharness connectors(downstream).

q Crossed HO2S wiring at the 104-pin harness connectors(downstream).


30/55


P1130 - Lackof HO2S-11Switch, FuelTrim at Limit

The HEGO Sensoris monitored forswitching. The testfails when the HO2Sfails to switch due tocircuit or fuel at orexceeding acalibrated limit.

q Electrical:q Short to VPWR in harness

or HO2Sq Water in harness

connectorq Open/Shorted HO2S

circuitq Corrosion or poor mating

terminals and wiringq Damaged HO2Sq Damaged PCM

q Fuel System:q Excessive fuel pressureq Leaking/contaminated fuel

injectorsq Leaking fuel pressure

regulatorq Low fuel pressure or

running out of fuel

q Vapor recovery systemq Induction System:

q Air leaks after the MAFq Vacuum Leaksq PCV systemq Improperly seated engine

oil dipstickq EGR System:

q Leaking gasketq Stuck EGR valveq Leaking diaphragm or

EVRq Base Engine:

q Oil overfillq Cam timingq Cylinder compressionq Exhaust leaks before or

near the HO2S(s)

A fuel control HO2S Pswitching across 0.45volt from 0.2 to 0.9 voindicates a normalswitching HO2S.

P1131 - Lackof HO2S-11Switch,

SensorIndicates Lean

A HEGO sensorindicating lean at theend of a test is trying

to correct for an over-rich condition. Thetest fails when thefuel control systemno longer detectsswitching for acalibrated amount oftime.



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P1132 - Lackof HO2S-11Switch,SensorIndicates Rich

A HEGO sensorindicating rich at theend of a test is tryingto correct for an over-lean condition. Thetest fails when thefuel control systemno longer detectsswitching for acalibrated amount oftime.


P1137 - Lackof HO2S-12Switch,SensorIndicates Lean

The downstreamHO2S sensors areforced rich and leanand monitored bythe PCM. The testfails if the PCM doesnot detect the outputof the HO2S in a

calibrated amount oftime.

q Pinched, shorted, and corrodedwiring and pins

q Crossed sensor wiresq Exhaust leaksq Contaminated or damaged

sensor


See DTC P1137

P1150 - Lackof HO2S-21Switch, FuelTrim at Limit

See DTC P1130


A HEGO sensorindicating lean at theend of a test is tryingto correct for an over-rich condition. Thetest fails when fuelcontrol system nolonger detectsswitching for acalibrated amount of

time.



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A HEGO sensorindicating rich at theend of a test is tryingto correct for an over-lean condition. Thetest fails when thefuel control systemno longer detectsswitching for acalibrated amount oftime.



See DTC P1137

P1158 - Lackof HO2S-22Switch,

SensorIndicates Rich

See DTC P1137

P1168 - FuelRail PressureSensor inRange ButLow

The comprehensivecomponent monitor(CCM) monitors theFRP pressure foracceptable fuelpressure. The testfails when the fuelpressure falls belowa calibrated value.

q Low fuel pressureq Damaged FRP sensorq Excessive resistance in circuitq Low or no fuel

q A FRP PID valuebelow 551 kpa (80psi) indicates a fa

q Low or no fuq A FRP PID value

greater than 896 k(130 psi) indicatesfailure

P1169 - FuelRail Pressure(FRP) Sensorin Range ButHigh

The comprehensivecomponent monitor(CCM) monitors theFRP pressure foracceptable fuelpressure. The testfails when the fuelpressure falls belowor exceeds aminimum/maximum

calibrated value fora calibrated periodof time.

q High fuel pressureq Low fuel pressureq Damaged FRP sensorq Excessive resistance in circuit


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P1180 - FuelDeliverySystem - Low

The PCM receivesfuel tank pressure(FTP) informationfrom the natural gasmodule (NG), whichuses the informationto infer fuel railpressure (FRP). The

test fails when theinferred pressure isless than a minimumcalibrated value.

q Restriction in the fuel lineq Plugged fuel filter

P1181 - FuelDeliverySystem - High

The PCM receivesfuel tank pressure(FTP) informationfrom the natural gasmodule (NG), whichuses the informationto infer fuel rail

pressure (FRP). Thetest fails when theinferred pressure ishigher than amaximum calibratedvalue.

q Fuel pressure regulator

P1183 -Engine OilTemperature(EOT) SensorCircuitMalfunction

Indicates EOT circuitbecameintermittently openor shorted whileengine was running.


Using signal simulatiodisconnect sensor ansimulate 1.0V on sensignal circuit. Simulat1.0V signal and scanPID voltage value shobe similar. If voltage isimilar check sensor,voltage is not similarcheck related circuit aPCM.



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P1184 - Engine OilTemperature (EOT)Sensor Out of Self-TestRange

Indicates EOTsignal was out ofSelf-Test range.Correct range forKOER is.3-1.2volts.

q Damaged harnessq Damaged sensorq Damaged harness

connectorq Damaged PCM

Using signal simulatiodisconnect sensor ansimulate 1.0V on sensignal circuit. Simulat1.0V signal and scanPID voltage value shobe similar. If voltage isimilar check sensor,voltage is not similarcheck related circuit aPCM.

P1229 - SuperchargerIntercooler Pump (ICP)Pump Not Operating

The ICP DTC willbe set when thePCM is calling forthe pump to beoperating but nocurrent is beingdetected.

q Pump motor opencircuited

q Pump relay coil openq Open circuit between

relay and pumpq Damaged PCMq Pump motor shortedq Open circuit between

PCM and relayq Poor pump ground

connection

Check for voltage atrelay, check fuse inpower feed, checkground connection ofpump motor, PID reais on/off.

P1232 - Low Speed FuelPump Primary CircuitMalfunction

Monitors the lowspeed fuel pump(LFP) primarycircuit output fromthe PCM. The testfails if: When theLFP circuit iscommanded on(grounded),excessive currentdraw is detectedon the LFP circuit;or when the LFPcircuit iscommanded off,voltage is notdetected on theLFP circuit (the

PCM expects todetect VPWRvoltage comingthrough the lowspeed fuel pumprelay coil to theLFP circuit).

q Open or shorted lowfuel pump (LFP)circuit

q Open VPWR to lowspeed fuel pumprelay

q Damaged low speedfuel pump relay

q Damaged PCM

s An open circuit orshort to ground caonly be detected wthe low speed fuepump.

s A short to power conly be detected wthe low speed fuepump commandedon.

s During KOEO andKOER Self-Test, tlow speed fuel puoutput command wbe cycled on and


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P1233 - Fuel SystemDisabled or Offline

Note: ForLS6/LS8, P1233indicates the PCMis not receiving thefuel levelinformation onSCP from the rearelectronics module

(REM). Refer tothe WorkshopManual Section413-01 fordiagnostics.Monitors the fuelpump monitor(FPM) circuit fromthe fuel pumpdriver module(FPDM). With the

key on, the FPDMcontinuously sendsa duty cycle signalto the PCMthrough the FPMcircuit. The testfails if the PCMstops receiving theduty cycle signal.

q Inertia fuel shutoff(IFS) switch needs tobe reset

q Open FPDM groundcircuit

q Open or shorted FPMcircuit

q Damaged IFS switchq

Damaged FPDMq Damaged PCMq Also for Escort/Tracer

and Mustang:s Open FPDM

PWR circuits Open B+ circuit

to constantcontrol relaymodule(CCRM) pin 11

s Open ground toCCRM pin 18(Mustang)

s DamagedCCRM

q Also for Continental:s Open VPWR

circuit to FPDM

The PCM expects to one of the following dcycle signals from theFPDM on the FPMcircuit: 1) 50% (500msec on, 500 msec oall OK. 2) 25% (250msec on, 750 msec o

FPDM did not receivefuel pump (FP) dutycycle command fromPCM, or the duty cycthat was received wainvalid. 3) 75% (750msec ON, 250 OFF),FPDM has detected afault in the circuitsbetween the FPDM athe fuel pump.

P1234 - Fuel SystemDisabled or Offline

See DTC P1233.P1234 is identical

to P1233 exceptP1234 will notilluminate the MIL.

P1235 - Fuel PumpControl Out Of Range

Note: ForLS6/LS8, theFPDM functionsare incorporated inthe RearElectronics Module(REM). Also, the

REM does not usea FPM circuit.Diagnosticinformation will besent through SCP.Indicates that theFPDM hasdetected an invalidor missing FPcircuit signal fromthe PCM. The

q FP circuit open orshorted

q Damaged FPDM.q Damaged PCM

The FPDM sends a 2duty cycle (250 msecON, 750 msec OFF)through the FPM circto the PCM while thefault is being detectedthe FPDM. If the fault

no longer detected, thPDM will return tosending an "all OK"(50% duty cycle)message to the PCMThe PCM will keepP1235 stored inContinuous Memory.


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FPDM will send amessage to thePCM through theFPM circuit,indicating that thisfailure has beendetected. ThePCM will set theDTC when themessage isreceived.

P1236 - Fuel PumpControl Out Of Range

See DTC P1235.P1236 is identicalto P1235 exceptP1236 will notilluminate the MIL.

P1237 - Fuel PumpSecondary CircuitMalfunction

Note: ForLS6/LS8, theFPDM functions

are incorporated inthe rear electronicsmodule (REM).Also, the REMdoes not use aFPM circuit.Diagnosticinformation will beset through SCP.Indicates that theFPDM has

detected a fuelpump secondarycircuit fault. TheFPDM will send amessage to thePCM through theFPM circuit,indicating that thisfailure has beendetected. The

PCM will set theDTC when themessage isreceived.

q Open or shorted FPPWR circuit

q Open FP Rtn circuitto FPDM

q Open or shortedcircuit in the fuelpump

q Locked fuel pumprotor

q Damaged FPDMq For LS6/LS8, circuits

associated with theFuel Pump relay

s The FPDM sends75% duty cycle (7msec ON, 250 ms

OFF) through theFPM circuit to thePCM while the faubeing detected byFPDM. If the faultno longer detectedthe PCM will retursending an "all OK(50% duty cycle)message to the PThe PCM will kee

P1237 stored inContinuous Memo

s The FPDM contropump speed bysupplying a "variaground on the RTcircuit.

P1238 - Fuel PumpSecondary CircuitMalfunction

See DTC P1237.P1238 is identicalto P1237 exceptP1238 will notilluminate the MIL.


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P1244 - Generator LoadInput Low

The PCM monitorsthe GLI circuit, andwill set the DTCwhen the input isbelow calibratedlimit for acalibrated amountof time.

q ALI circuit open orshort

q Damaged voltageregulator/generator

q Damaged PCM

Verify operation ofcharging system.

P1245 - Generator LoadInput High The PCM monitorsthe GLI circuit, andwill set the DTCwhen the input isabove a calibratedlimit for acalibrated amountof time.

qALI circuit open orshort

q Damaged voltageregulator/generator

q Damaged PCM

Verify operation ofcharging system.

P1246 - Generator LoadInput (2.0LContour/Mystique/Cougar)

The PCM monitorsthe GLI circuit, andwill set the DTC

when the input isnot within acalibrated limit fora calibratedamount of time.

q ALI circuit concern.q Damaged voltage

regulator/generatorq Damaged PCM.

q Verify operation ocharging system.

q Verify battery is atproper charge.

P1246 - Generator LoadInput Failed (All Others)

The PCM monitorsgenerator loadfrom thegenerator/regulatorin the form offrequency. Thefrequency range isdetermined by thetemperature of thevoltage regulatorwhere 97%represents fullload, below 6%means no load.

q Generator circuitshort to GND

q Generator circuitshort to PWR

q Generator circuitopen

q Generator drivemechanism

q Damagedgenerator/regulatorassembly

q Damaged PCM

s Verify battery voltis 14.5V.

s Verifygenerator/regulatohas the correct panumber.

P1260 - Theft Detected -Vehicle Immobilized

Indicates the anti-theft system has

determined a theftcondition existedand the engine isdisabled.

q Previous theftcondition

q Anti-Theft Systemfailure

Using the proper key remote or keyless en

to unlock the door widisarm the anti-theftsystem and enable fudelivery to start thevehicle. Also check atheft system for DTCs


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P1270 - EngineRPM/Vehicle SpeedLimiter

Indicates thevehicle has beenoperated in amanner whichcaused the engineor vehicle toexceed acalibration limit.The engine rpmand vehicle speedare continuouslymonitored by thePCM. The DTC isset when the rpmor speed fall out ofcalibrated range.For additionalinformation on theengine rpm/vehicle

speed limiter, referto Section 1,

Electronic EngineControl (EC)System,Powertrain ControlSoftware.

q Wheel slippage(water, ice, mud andsnow)

q Excessive enginerpm in Neutral

q Vehicle drive at ahigh rate of speed

The DTC indicates thvehicle has beenoperated in a mannewhich caused the engor vehicle speed toexceed a calibrated li

P1285 - Cylinder HeadOver Temperature Sensed

Indicates anengine overheatcondition wassensed by thecylinder headtemperaturesensor.

q Low engine coolantlevel

q Base engineconcerns

q Engine coolingsystem concerns

On some applicationswhen this fault occursthe Engine Temperatwarning indicator willilluminate or force thetemperature gauge toH (Hot) zone by groucircuit 39.

P1288 - Cylinder HeadTemperature (CHT)Sensor Circuit Out of Self-Test Range

Indicates the CHTsensor is out ofSelf-Test range.Engine not atoperatingtemperature.

q Engine overheatingq Damaged harness

connectorq Damaged PCMq Low engine coolant

level

q Damaged CHTsensor

Bring engine to operatemperature. If cold, run self-test. If engineover-heats check coosystem.


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P1289 - Cylinder HeadTemperature (CHT)Sensor Circuit High Input(PCM STRATEGIES UP TOAND INCLUDING 1998)

Indicates a CHTsensor circuitmalfunction(shorted).

q Grounded circuit inCHT harness

q Damaged CHTsensor

q Improper harnessconnection

q Damaged PCM

Using signal simulatiodisconnect sensor ansimulate a voltage onsensor signal circuit.Simulated 1.0V signaand scan PID voltagevalue should be similIf voltage is similar ch

sensor, if voltage is nsimilar check relatedcircuit and PCM. NoteDTC P0117 may alsoreported, this willactivate the MIL light

P1289 - Cylinder HeadTemperature (CHT)Sensor Circuit High Input(PCM STRATEGIES 1999AND BEYOND)

Indicates a CHTsensor circuitmalfunction(open).

q Open circuit in CHTharness

q Damaged CHTsensor


q Damaged PCM

Using signal simulatiodisconnect sensor ansimulate a voltage onsensor signal circuit.Simulated 1.0V signa

and scan PID voltagevalue should be similIf voltage is similar chsensor, if voltage is nsimilar check relatedcircuit and PCM. NoteDTC P0118 may alsoreported, this willactivate the MIL light

P1290 - Cylinder HeadTemperature (CHT)Sensor Circuit Low Input(PCM STRATEGIES UP TOAND INCLUDING 1998)

Indicates a CHTsensor circuitmalfunction(open).

q Open circuit in CHTharness

q Damaged CHTsensor


q Damaged PCM

Using signal simulatiodisconnect sensor ansimulate a voltage onsensor signal circuit.Simulated 1.0V signaand scan PID voltagevalue should be similIf voltage is similar chsensor, if voltage is nsimilar check relatedcircuit and PCM. NoteDTC P0118 may also

reported, this willactivate the MIL light


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P1290 - Cylinder HeadTemperature (CHT)Sensor Circuit Low Input(PCM STRATEGIES 1999AND BEYOND)

Indicates a CHTsensor circuitmalfunction(shorted).

q Grounded circuit inCHT harness

q Damaged CHTsensor


q Damaged PCM

Using signal simulatiodisconnect sensor ansimulate a voltage onsensor signal circuit.Simulated 1.0V signaand scan PID voltagevalue should be similIf voltage is similar chsensor, if voltage is nsimilar check relatedcircuit and PCM. NoteDTC P0117 may alsoreported, this willactivate the MIL light

P1299 - Cylinder HeadOver TemperatureProtection Active

Indicates anengine overheatcondition wasdetected by thecylinder head

temperature (CHT)sensor. An FMEMStrategy called Fail-safe Cooling wasactivated to coolthe engine.

q Engine coolingsystem concerns

q Low engine coolantlevel

q Base engineconcerns

Refer to Section 1,

Electronic EngineControl (EC) Systemmore information on safe Cooling Strategy

and cylinder headtemperature sensor.

P1309 - Misfire MonitorDisabled

When the misfiremonitor isdisabled, usuallydue to the inputsignal generatedby the camshaftposition (CMP)sensor, by sensingthe passage ofteeth from theCMP wheel.

q Camshaft positionsensor

q Powertrain controlmodule

q ECT, MAF, and CKPsensors

Verify the CMP isinstalled correctly andnot out ofsynchronization.

P1380 - Variable CamTiming Solenoid A CircuitMalfunction

Thecomprehensivecomponentmonitor(CCM)

monitors the VCTcircuit to the PCMfor high and lowvoltage. If duringtesting voltage wasto fall below acalibrated limit acalibrated amountof time the test willfail.

q Open or short VCTcircuit

q Open VPWR circuitq Damaged PCMq Open or short VCT

solenoid valve

DTC P1380 is a VCTcircuit check. Testingshould include wires,solenoid coil and PCM


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P1381 - Variable CamTiming Over-advanced(Bank 1)

Thecomprehensivecomponentmonitor (CCM)monitors the VCTposition for an over-advancedcamshaft timing.The test fails whenthe camshafttiming exceeds amaximumcalibrated value orremains in anadvanced position.

q Cam timingimproperly set

q No oil flow to the VCTpiston chamber

q Low oil pressureq VCT solenoid valve

stuck closedq Camshaft advance

mechanism binding(VCT unit)

P1381 DTC is a checthe VCT unit. Testingshould not includeelectrical checks.Diagnostics and repafor the VCT unit arelocated in the WorkshManual.

P1383 - Variable CamTiming Over-retarded(Bank 1)

Thecomprehensivecomponentmonitor (CCM)

monitors the VCTposition for over-retarded camshafttiming. The testfails when thecamshaft timingexceeds amaximumcalibrated value orremains in anretarded position.

q Cam timingimproperly set

q Continuous oil flow tothe VCT piston

chamberq VCT solenoid valve

stuck openq Camshaft advance

mechanism binding(VCT unit)

DTC P1383 is a checthe VCT unit. Testingshould not includeelectrical checks. Eng

will idle rough, hardstarting and may stalDiagnostics and repafor the VCT unit arelocated in the WorkshManual.

P1390 - Octane Adjust(OCTADJ)

The octane adjustis softwareactivated in thepowertrain controlmodule, used toretard spark timingby three degrees.The hardwareshorting bar hasbeen removed.

q Powertrain controlmodule (PCM)

Do not activate theoctane adjust softwarunless directed by aTechnical ServiceBulletin.


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P1400 - DPF EGR SensorCircuit Low VoltageDetected

The EGR monitorchecks the DPFEGR sensor signalto the PCM for lowvoltage. The testfails when theaverage voltage tothe PCM drops to

a voltage less thanthe minimumcalibrated value.

q DPFEGR circuit shortto GND

q Damaged DPF EGRsensor

q VREF short to GNDq Damaged PCM

A DPF EGR PID readless than 0.2 volt withthe key ON and enginOFF or running,indicates a hard fault

P1401 - DPF EGR SensorCircuit High VoltageDetected

The EGR monitorchecks the DPFEGR sensor signalto the PCM forhigh voltage. Thetest fails when theaverage voltage tothe PCM goes to a

voltage greaterthan the maximumcalibrated value.

q DPF EGR circuitopen

q VREF short to PWRq Damaged DPF EGR

sensorq DPFEGR circuit short

to PWRq SIG RTN circuit openq Damaged PCM

A DPF EGR PID readgreater than 4.5 voltswith the key ON andengine OFF or runninindicates a hard fault

P1405 - DPF EGR SensorUpstream Hose Off orPlugged

While driving, theEGR monitorcommands theEGR valve closedand checks thedifferentialpressure acrossthe EGR orifice.The test fails whenthe signal from theDPF EGR sensorindicates EGR flowis in the negativedirection.

q Upstream hose isdisconnected

q Upstream hose isplugged (ice)

q Plugged or damagedEGR tube

s Look for signs ofwater or icing in h

s Verify hoseconnection androuting (no excessdips)

s Verify DPF EGRsensor propermounting andfunction (view DPEGR PID whileapplying andreleasing vacuumdirectly to sensor a hand pump)

P1406 - DPF EGR SensorDownstream Hose Off orPlugged

While driving, theEGR monitorcommands the

EGR valve closedand checks thedifferentialpressure acrossthe EGR orifice.The test fails whenthe signal from theDPF EGR sensorcontinues toindicate EGR floweven after the

q Downstream hose isdisconnected

q Downstream hose isplugged (ice)

q Plugged or damagedEGR tube

s Look for signs ofwater or icing in h

s Verify connection routing (no excessdips)

s Verify DPF EGRsensor propermounting andfunction (viewDPFEGR PID whiapplying andreleasing vacuumdirectly to sensor a hand pump)


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EGR valve iscommandedclosed.

P1408 - EGR Flow Out ofSelf-Test Range

This test isperformed duringthe KOER ondemand self-testonly. The EGR

system iscommanded ON ata fixed enginespeed. The testfails and the DTCis output when themeasured EGRflow falls below therequired calibratedminimum.

See Possible Causes forDTC P0401.

P1409 - EGR Vacuum

Regulator SolenoidCircuit Malfunction

This test checks

the electricalfunction of theEGRVR. solenoid.The test fails whenthe EGRVR circuitvoltage is eithertoo high or too lowwhen compared tothe expectedvoltage range. TheEGR system must

be enabled for thetest to becompleted.

q EGRVR circuit openq VPWR open to

EGRVR solenoidq EGRVR circuit short

to VPWR or GNDq Damaged EGRVR

solenoidq Damaged PCM

The EGR vacuum

regulator solenoidresistance is from 2640 ohms.


P1411 - SecondaryAir Injection (AIR)system

downstream flow

The secondary airinjection system doesnot detect the

presence of air in theexhaust whenintroduced by thesecondary air injectionsystem

q Electric AIR Pumpq Hose from AIR pump

leak

q AIR bypass solenoidleak/blocked

q Hose from AIR pumpblocked

q AIR bypass solenoidstuck open/closed

In order to test the AIRpump, it must be capabof driving the HO2S lea


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P1413 - SecondaryAir Injectionsystem monitorcircuit low

The secondary airinjection systemmonitor circuit is low,indicating the electricalAIR pump is offalthough the electricalAIR pump wascommanded on by the

PCM.

q Open B+ circuitq Open AIR circuitq Damaged PCMq AIR circuit short to

groundq Damaged AIR pumpq Damaged Solid State

Relay

The AIR Monitor circuitheld low by the resistapath through the AIRpump when the pump off. Also, look for opencircuit from SSR to AIRpump.

P1414 - SecondaryAir Injectionsystem monitorcircuit high

The secondary airinjection systemmonitor circuit is high,indicating the electricalAIR pump is onalthough the electricalAIR pump wascommanded off by thePCM.

q Open AIR monitorcircuit from the pump

q AIR circuit short topower

q Damaged Solid Staterelay

q Open AIR pump groundq Damaged AIR pumpq Damaged PCM

P1443 - EVAP

Control SystemCanister PurgeValve (Mechanical)Malfunction

Monitors the fuel vapor

flow between theengine intake manifoldand the EVAPcanister. The systemfailure occurs when aleak or blockagebetween the intakemanifold, the EVAPcanister purge valveand the EVAP canisteris detected by thePCM.

q Pinched, blocked orplugged fuel vaportubes/hoses (exceptbetween fuel tank andEVAP canister)

q Damaged EVAPcanister

q Disconnected, crackedor cut fuel vaportubes/hoses (exceptbetween fuel tank andEVAP canister)

q Damaged EVAPcanister purge valve

Check for audible vacu

noise in the enginecompartment or significfuel odor in the enginecompartment or near thEVAP canister.

P1443 - Very SmallOr No Purge FlowCondition (mid-year 4.0L SOHCExplorer only)

A fuel tank pressurechange greater than aminus (-) 7 inches ofH2O in 30 secondshas occurred withpurge (fuel vapor) flowless than 0.02 poundsper minute.

q Blocked fuel vaporhose between EVAPcanister purge valveand FTP sensor.

q Blocked fuel vaporhose between EVAPcanister purge valveand engine intake

manifold.q Blocked vacuum hose

between EVAP canisterpurge valve-solenoidand engine intakemanifold.

q EVAP canister purgevalve stuck closed(mechanically).

Check for blockagesbetween the fuel tank,EVAP canister purgevalve and engine intakmanifold. Checkobstructions in the EVAcanister purge valvediaphragm and ports.


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P1450 - Unable toBleed Up Fuel TankVacuum

Monitors the fuel vaporvacuum and pressurein the fuel tank. Thesystem failure occurswhen the EVAPrunning loss monitordetects excessive fueltank vacuum with theengine running (butnot at idle).

q Blockages or kinks inEVAP canister tube orEVAP canister purgeoutlet tube (betweenfuel tank, EVAPcanister purge valveand EVAP canister)

q Fuel filler cap stuckclosed (no vacuumrelief)

q Contaminated fuelvapor elbow on EVAPcanister

q Restricted EVAPcanister

q CV solenoid stuck open(partially or fully)

q Plugged CV solenoidfilter

q EVAP canister purgevalve stuck open

q VREF circuit open(harness near FTPsensor, FTP sensor orPCM)

q Damaged FTP sensorP1451 - EVAPControl SystemCanister VentSolenoid Circuit

Malfunction

Monitors the canistervent (CV) solenoidcircuit for an electricalfailure. The test fails

when the signal movesoutside the minimumor maximum allowablecalibrated paramet

trouble codes obdii[1]

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