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Home >> Jeep >> 2007 >> Liberty Limited, 4WD, Part Time >> Repair and Diagnosis >> Engine Performance >> System >> DTCS P0112 To P0155 - Gas >> P0131-O2 Sensor 1/1 Circuit Low >> Diagnostic Test
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Diagnostic Test

  1. 1) ACTIVE DTC 

    Turn the ignition on.

    With a scan tool, select View DTCs. Record DTC and Freeze Frame information.

    Start the engine and allow it to idle for at least 60 seconds.

    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, select View DTCs.

    Is the DTC Active or Pending at this time? 

    Yes 

    1. Go to  2).

    No 

    1. Refer to INTERMITTENT CONDITION Diagnostic Procedure.
  2. 2) (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT 

    Turn the ignition off.

    Disconnect the 1/1 O2 Sensor harness connector.

    Ignition on, engine not running.

    With a scan tool, monitor the O2 Sensor voltage.

    Is the 1/1 O2 Sensor voltage between 4.1 and 5.0 volts? 

    Yes 

    1. Go to  3).

    No 

    1. Go to  5).
  3. 3) O2 SENSOR 
    Fig 1: Checking O2 Sensor Return Downstream/Upstream Circuit Voltage
    GC0038459Courtesy of CHRYSLER LLC

    Measure the voltage on the (K902) O2 Return Upstream circuit in the O2 Sensor harness connector.

    Is the voltage at 2.5 volts? 

    Yes 

    1. Replace the O2 Sensor.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  4).
  4. 4) (K902) O2 RETURN UPSTREAM CIRCUIT SHORTED TO GROUND 
    Fig 2: Checking O2 Return Circuit For Short To Ground
    GC0038463Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the C1 PCM harness connector.

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

    Is the resistance below 100 ohms? 

    Yes 

    1. Repair the short to ground in the (K902) O2 Return Upstream circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  8).
  5. 5) (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT SHORTED TO GROUND 
    Fig 3: Checking O2 Sensor 1/1 Signal Circuit For Short To Ground
    GC0038462Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the C1 and C2 PCM harness connectors.

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

    Is the resistance below 100 ohms? 

    Yes 

    1. Repair the short to ground in the (K41) O2 Sensor 1/1 Signal circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  6).
  6. 6) (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT SHORTED TO THE (K902) O2 RETURN UPSTREAM CIRCUIT  
    Fig 4: Checking O2 Sensor 1/1 Signal Circuit For Short To Return Circuit
    GC0038461Courtesy of CHRYSLER LLC

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

    Is the resistance below 100 ohms? 

    Yes 

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

    No 

    1. Go to  7).
  7. 7) (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT SHORTED TO THE (Z42) O2 1/1 HEATER GROUND CIRCUIT  
    Fig 5: Checking O2 Sensor 1/1 Signal Circuit For Short To Heater Ground Circuit
    GC0038460Courtesy of CHRYSLER LLC

    Measure the resistance between the (K41) O2 Sensor 1/1 Signal circuit and the (Z42) O2 1/1 Heater ground circuit in the O2 Sensor harness connector.

    Is the resistance below 100 ohms? 

    Yes 

    1. Repair the short between the (Z42) O2 1/1 Heater ground circuit and the (K41) O2 Sensor 1/1 Signal circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  8).
  8. 8) PCM  
    NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

    Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

    Were there any problems found? 

    Yes 

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

    No 

    1. Replace and program the Powertrain Control Module per Service Information.
    2. Perform POWERTRAIN VERIFICATION TEST .