Possible causes – Faulty Clutch Position Sensor– Clutch Position Sensor harness is open or shorted– Clutch Position Sensor circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Faulty Clutch Switch– Misadjusted Clutch Switch– Clutch Switch harness is open or shorted– Clutch Switch circuit poor electrical connection– Faulty Engine Control Module (ECM) Tech notes Check clutch switch adjustment, the switch should open and close when

Possible causes – Faulty Crankshaft Position (CKP) Sensor– Crankshaft Position (CKP) Sensor harness is open or shorted– Crankshaft Position (CKP) Sensor circuit poor electrical connection– Communication error between the Engine Control Module (ECM) and Transmission Control Module (TCM) When is

Possible causes – Faulty Crankshaft Position (CKP) Sensor– Crankshaft Position (CKP) Sensor harness is open or shorted– Crankshaft Position (CKP) Sensor circuit poor electrical connection– Communication error between the Engine Control Module (ECM) and Transmission Control Module (TCM) When is

Possible causes – Faulty Crankshaft Position (CKP) Sensor– Crankshaft Position (CKP) Sensor harness is open or shorted– Crankshaft Position (CKP) Sensor circuit poor electrical connection– Communication error between the Engine Control Module (ECM) and Transmission Control Module (TCM) When is

Possible causes – Faulty EGR volume control solenoid valve– EGR volume control solenoid valve harness is open or shorted– EGR volume control solenoid valve circuit poor electrical connection– EGR temperature sensor and circuit When is the code detected? An improper

Possible causes – Faulty Engine Control Module (ECM) power relay– ECM power relay harness is open or shorted– ECM power relay circuit poor electrical connection– Faulty (ECM) Tech notes Check all the ECM fuses, if the fuses are OK try

Possible causes – Faulty Engine Control Module (ECM)– ECM harness is open or shorted– ECM circuit poor electrical connection– Shorted sensor on 5 volt circuit Tech notes There is a factory service bulletin for the P0642 code for the following

Possible causes – Faulty Engine Control Module (ECM)– ECM harness is open or shorted– ECM circuit poor electrical connection– Shorted sensor on 5 volt circuit When is the code detected? The Engine Control Module (ECM) has detected the sensor 5

Possible causes – Faulty Evaporative Emission (EVAP) Purge Solenoid Control– Evaporative Emission (EVAP) Purge Solenoid Control harness is open or shorted– Evaporative Emission (EVAP) Purge Solenoid Control circuit poor electrical connection When is the code detected? – An excessively high

Possible causes – Faulty Evaporative Emission (EVAP) Purge Solenoid Control– Evaporative Emission (EVAP) Purge Solenoid Control harness is open or shorted– Evaporative Emission (EVAP) Purge Solenoid Control circuit poor electrical connection When is the code detected? – An excessively low

Possible causes – Faulty Evaporative Emission (EVAP) Purge Solenoid Control– Evaporative Emission (EVAP) Purge Solenoid Control harness is open or shorted– Evaporative Emission (EVAP) Purge Solenoid Control circuit poor electrical connection When is the code detected? The Engine Control Module

Possible causes – Faulty Evaporative Emission (EVAP) Purge Solenoid Control– Evaporative Emission (EVAP) Purge Solenoid Control harness is open or shorted– Evaporative Emission (EVAP) Purge Solenoid Control circuit poor electrical connection When is the code detected? The Engine Control Module

Possible causes – Faulty Exhaust Gas Recirculation (EGR) Solenoid– Exhaust Gas Recirculation (EGR) Solenoid harness is open or shorted– Exhaust Gas Recirculation (EGR) Solenoid circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P0489

Possible causes – Faulty Exhaust Gas Recirculation (EGR) Solenoid– Exhaust Gas Recirculation (EGR) Solenoid harness is open or shorted– Exhaust Gas Recirculation (EGR) Solenoid circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P0490

Possible causes – Faulty fan control relay– Fan control relay harness is open or shorted– Fan control relay circuit poor electrical connection– Faulty cooling fan 1– Fan cooling fan harness is open or shorted– Fan cooling fan circuit poor electrical

Possible causes – Faulty fan control relay– Faulty cooling fan 2– Fan control relay harness is open or shorted– Fan control relay circuit poor electrical connection– Fan cooling fan harness is open or shorted– Fan cooling fan circuit poor electrical

Possible causes – Faulty Front Heated Oxygen Sensor Bank 1– Front Heated Oxygen Sensor Bank 1 harness is open or shorted– Front Heated Oxygen Sensor Bank 1 circuit poor electrical connection– Inappropriate fuel pressure– Faulty fuel injectors– Intake air leaks

Possible causes – Faulty Front Heated Oxygen Sensor Bank 1– Front Heated Oxygen Sensor Bank 1 harness is open or shorted– Front Heated Oxygen Sensor Bank 1 circuit poor electrical connection– Inappropriate fuel pressure– Faulty fuel injectors– Intake air leaks

Possible causes – Faulty Front Heated Oxygen Sensor Bank 1– Front Heated Oxygen Sensor Bank 1 harness is open or shorted– Front Heated Oxygen Sensor Bank 1 circuit poor electrical connection– Inappropriate fuel pressure– Faulty fuel injectors– Intake air leaks