Possible causes – Fuel delivery system– Engine Coolant Temperature (ECT) sensor or wiring connectors– MAP sensor or wiring connectors– O2 sensor wiring or connectors– Engine mechanical system Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P1129 JEEP

Possible causes – Fuel delivery system– Manifold Absolute Pressure (MAP) sensor or wiring connectors– O2 sensor wiring or connectors– Engine mechanical system– Faulty Powertrain Control Module (PCM) Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P1128 JEEP

Possible causes – Incorrect fuel pressure– Faulty fuel pressure solenoid– Air in fuel system When is the code detected? The ECM has determined that the fuel rail pressure is too high for a specific condition Symptoms – Engine Light ON

Possible causes – Incorrect fuel pressure– Faulty Fuel Rail Pressure Solenoid– Fuel Rail Pressure Solenoid harness is open or shorted– Fuel Rail Pressure Solenoid circuit poor electrical connection– Air in fuel system When is the code detected? The Engine Control

Possible causes – Incorrect fuel pressure– Faulty Fuel Rail Pressure Solenoid– Fuel Rail Pressure Solenoid harness is open or shorted– Fuel Rail Pressure Solenoid circuit poor electrical connection– Air in fuel system When is the code detected? The Engine Control

Possible causes – Incorrect fuel pressure– Faulty Fuel Rail Pressure Solenoid– Fuel Rail Pressure Solenoid harness is open or shorted– Fuel Rail Pressure Solenoid circuit poor electrical connection– Air in fuel system When is the code detected? The Engine Control

Possible causes – Large vacuum leak on the engine – Faulty Manifold Pressure (MAP) sensor – Faulty Throttle Position Sensor (TPS)– Faulty Engine Control Module (ECM) Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P2074 JEEP Description

Possible causes – Leak Detection Pump (LDP) harness is open or shorted – Leak Detection Pump (LDP) poor electrical connection – Faulty Leak Detection Pump (LDP) When is the code detected? Malfunction is detected when the Powertrain Control Module (PCM)

Possible causes – Leak Detection Pump (LDP) harness is open or shorted – Leak Detection Pump (LDP) poor electrical connection – Faulty Leak Detection Pump (LDP) When is the code detected? Malfunction is detected when the Powertrain Control Module (PCM)

Possible causes – Leak Detection Pump (LDP) pressure hose obstructed – Faulty Leak Detection Pump (LDP) – Obstructed hose – EVAP canister obstructed When is the code detected? Malfunction is detected when during system monitor test the Powertrain Control Module

Possible causes – Low coolant level– Faulty Engine Coolant Temperature Sensor– Stuck or leaking thermostat– Engine Coolant Temperature Sensor harness is open or shorted– Engine Coolant Temperature Sensor circuit poor electrical connection– Faulty Powertrain Control Module (PCM) Symptoms – Engine

Possible causes – Low oil pressure– Restricted oil passage– Engine mechanical condition– Multiple Displacement System (MDS) Solenoid fault Tech notes Although in some cases changing the engine oil may fix the problem, usually the Multi Displacement System Solenoid may need

Possible causes – Low oil pressure– Restricted oil passage– Engine mechanical condition– Multiple Displacement System (MDS) Solenoid fault Tech notes Although in some cases changing the engine oil may fix the problem, usually the Multi Displacement System Solenoid may need

Possible causes – Low transmission fluid– Dirty Transmission fluid– Internal transmission failure Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P0897 JEEP Description With each transition from full Torque Convertor to partial Torque Convertor engagement for AC

Possible causes – Manifold Differential Pressure sensor harness is open or shorted– Manifold Differential Pressure sensor circuit poor electrical connection– Faulty Manifold Differential Pressure sensor Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P1400 JEEP Description The

Possible causes – Manifold flow valve harness is open or shorted– Manifold flow valve circuit poor electrical connection– Faulty Manifold flow valve– Intake manifold– Faulty Powertrain Control Module (PCM) Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Manifold flow valve harness is open or shorted– Manifold flow valve circuit poor electrical connection– Faulty Manifold flow valve– Intake manifold– Faulty Powertrain Control Module (PCM) Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Manifold flow valve harness is open or shorted– Manifold flow valve circuit poor electrical connection– Faulty Manifold flow valve– Intake manifold– Faulty Powertrain Control Module (PCM) Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Manifold flow valve harness is open or shorted– Manifold flow valve circuit poor electrical connection– Faulty Manifold flow valve– Intake manifold– Faulty Powertrain Control Module (PCM) Symptoms – Engine Light ON (or Service Engine Soon Warning Light)

Possible causes – Manifold flow valve harness is open or shorted– Manifold flow valve circuit poor electrical connection– Faulty Manifold flow valve– Intake manifold– Faulty Powertrain Control Module (PCM) Symptoms – Engine Light ON (or Service Engine Soon Warning Light)