Possible causes – Faulty fuel rail pressure sensor– Fuel rail pressure sensor harness is open or shorted– Fuel rail pressure sensor circuit poor electrical connection– Fuel pressure variation check Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Faulty Heated Oxygen Sensor– Heated Oxygen Sensor harness is open or shorted– Heated Oxygen Sensor circuit poor electrical connection– Exhaust leaks– Contaminated Heated Oxygen Sensor Tech notes Before replacing the Heated Oxygen Sensor, inspect the sensor connector

Possible causes – Faulty Heated Oxygen Sensor– Heated Oxygen Sensor harness is open or shorted– Heated Oxygen Sensor circuit poor electrical connection– Exhaust leaks– Contaminated Heated Oxygen Sensor Tech notes Before replacing the Heated Oxygen Sensor, inspect the sensor connector

Possible causes – Faulty Heated Oxygen Sensor– Heated Oxygen Sensor harness is open or shorted– Heated Oxygen Sensor circuit poor electrical connection– Exhaust leaks– Contaminated Heated Oxygen Sensor Tech notes Before replacing the Heated Oxygen Sensor, inspect the sensor connector

Possible causes – Faulty Heated Oxygen Sensor– Heated Oxygen Sensor harness is open or shorted– Heated Oxygen Sensor circuit poor electrical connection– Exhaust leaks– Contaminated Heated Oxygen Sensor Tech notes Before replacing the Heated Oxygen Sensor, inspect the sensor connector

Possible causes – Faulty Ignition Switch– Ignition Switch harness is open or shorted– Ignition Switch circuit poor electrical connection– Faulty Body Control Module (BCM) Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P1001 JEEP Description The Engine

Possible causes – Faulty Ignition Switch– Ignition Switch harness is open or shorted– Ignition Switch circuit poor electrical connection– Faulty Body Control Module (BCM) Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P1002 JEEP Description The Engine

Possible causes – Faulty Input Speed Sensor– Input Speed Sensor harness is open or shorted– Input Speed Sensor circuit poor electrical connection When is the code detected? The Transmission Control Module (TCM) has detected a correlation error between the two

Possible causes – Faulty Intake Air Temperature Sensor– Intake Air Temperature Sensor harness is open or shorted– Intake Air Temperature Sensor circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P1112 JEEP Description The

Possible causes – Faulty Intake Temperature sensor– Intake Temperature sensor harness is open or shorted– Intake Temperature sensor circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P1110 JEEP Description Intake manifold temp sensor

Possible causes – Faulty O2 Sensor 1/2– O2 Sensor 1/2 harness is open or shorted– O2 Sensor 1/2 circuit poor electrical connection – Exhaust leak– Faulty Powertrain Control Module (PCM) Symptoms – Engine Light ON (or Service Engine Soon Warning

Possible causes – Faulty O2 Sensor– O2 Sensor harness open or shorted– O2 Sensor circuit poor electrical connection When is the code detected? The ECM has detected a plausibility fault with the O2 sensor signal

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

Possible causes – Faulty short runner valve assembly– Short runner valve harness is open or shorted– Short runner valve circuit poor electrical connection– Faulty Powertrain Control Module (PCM) When is the code detected? The P1004 code is detected when the

Possible causes – Faulty Short Runner Valve– Short Runner Valve harness is open or shorted– Short Runner Valve circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P1288 JEEP Description Wide open throttle condition-short

Possible causes – Faulty Throttle Actuator Control (TAC) module– Throttle Actuator Control (TAC) module harness is open or shorted– Throttle Actuator Control (TAC) module circuit poor electrical connection (loose or broken wires) Symptoms – Engine Light ON (or Service Engine

Possible causes – Faulty Throttle Actuator Control Actuator– Throttle Actuator Control Actuator harness is open or shorted– Throttle Actuator Control Actuator circuit poor electrical connection When is the code detected? Engine Control Module (ECM) detects short in both circuits between

Possible causes – Faulty Transmission Control Module (TCM) Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P1631 JEEP Description Transmission Control Module (TCM) Internal Processor Clock Performance

Possible causes – Faulty Vacuum Reservoir Solenoid– Vacuum Reservoir Solenoid harness is open or shorted– Vacuum Reservoir Solenoid circuit poor electrical connection Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Faulty Viscous/Cabin Heater Relay– Viscous/Cabin Heater Relay harness is open or shorted– Viscous/Cabin Heater Relay circuit poor electrical connection When is the code detected? The ECM has detected an excessive current condition on the Viscous/Cabin Heater Relay