Diagnostic Test

2008 Jeep Compass Limited, AWD, StandardSECTION Diagnostic Test
  1. OXYGEN SENSOR 1/1 VOLTAGE 

    Start the engine and allow it to reach normal operating temperature.

    WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

    With a scan tool, monitor the 1/1 O2 Sensor Volts.

    Is the voltage less than 2.52 volts? 

    Yes 

    1. Go to  2.

    No 

    1. Refer to the *CHECKING FOR AN INTERMITTENT CONDITION Diagnostic Procedure.
  2. (K41) O2 1/1 SIGNAL CIRCUIT VOLTAGE 

    Turn the ignition off.

    Disconnect the Oxygen Sensor 1/1 harness connector.

    Turn the ignition on.

    With a scan tool, monitor the 1/1 O2 Sensor Volts.

    Is the voltage above 4.8 volts? 

    Yes 

    1. Go to  3.

    No 

    1. Go to  5.
  3. OXYGEN SENSOR 1/1 
    Fig 1: Measuring Voltage On (K902) O2 1/1 Return Circuit In Oxygen Sensor 1/1 Harness Connector
    GC0054008Courtesy of CHRYSLER LLC

    Measure the voltage on the (K902) O2 1/1 Return circuit in the Oxygen Sensor 1/1 harness connector.

    Is the voltage between 2.475 and 2.525 volts? 

    Yes 

    1. Replace the Oxygen Sensor 1/1.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Go to  4.
  4. (K902) O2 1/1 RETURN CIRCUIT SHORTED TO GROUND 
    Fig 2: Checking O2 Sensor 1/1 Return Circuit For Short To Ground
    GC0054010Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the Powertrain Control Module (PCM) harness connector.

    Measure the resistance between ground and the (K902) O2 1/1 Return circuit in the Oxygen Sensor 1/1 harness connector.

    Is the resistance below 100 ohms? 

    Yes 

    1. Repair the (K902) O2 1/1 Return circuit for a short to ground.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Go to  8.
  5. (K41) O2 1/1 SIGNAL CIRCUIT SHORTED TO GROUND 
    Fig 3: Checking O2 Sensor 1/1 Signal Circuit For Short To Ground
    GC0054009Courtesy of CHRYSLER LLC

    Measure the resistance between ground and the (K41) O2 1/1 Signal circuit in the Oxygen Sensor 1/1 harness connector.

    Is the resistance below 100 ohms? 

    Yes 

    1. Repair the (K41) O2 1/1 Signal circuit for a short to ground.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Go to  6.
  6. (K41) O2 1/1 SIGNAL CIRCUIT SHORTED TO THE (K902) O2 1/1 RETURN CIRCUIT 
    Fig 4: Checking O2 Sensor 1/1 Signal Circuit For Short To Return Circuit
    GC0054252Courtesy of CHRYSLER LLC

    Measure the resistance between the (K41) O2 1/1 Signal circuit and the (K902) O2 1/1 Return circuit in the Oxygen Sensor 1/1 harness connector.

    Is the resistance below 100 ohms? 

    Yes 

    1. Repair the short between the (K902) O2 1/1 Return circuit and the (K41) O2 1/1 Signal circuit.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Go to  7.
  7. (K41) O2 1/1 SIGNAL CIRCUIT SHORTED TO THE (Z916) GROUND CIRCUIT 
    Fig 5: Checking O2 Sensor 1/1 Signal Circuit For Short To Ground Circuit
    GC0054253Courtesy of CHRYSLER LLC

    Measure the resistance between the (K41) O2 1/1 Signal circuit and the (Z916) Ground circuit in the Oxygen Sensor 1/1 harness connector.

    Is the resistance below 100 ohms? 

    Yes 

    1. Repair the short between the (Z916) Ground circuit and the (K41) O2 1/1 Signal circuit.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Go to  8.
  8. POWERTRAIN CONTROL MODULE (PCM) 

    Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/1 and the Powertrain Control Module (PCM).

    Look for any chafed, pierced, pinched, or partially broken wires.

    Look for broken, bent, pushed out or corroded terminals.

    Refer to any Technical Service Bulletins that may apply.

    Were any problems found? 

    Yes 

    1. Repair as necessary.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
    2. Perform PCM VERIFICATION TEST .
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.