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Home >> Jeep >> 2021 >> Renegade Trailhawk >> Repair and Diagnosis >> Engine Performance >> System >> 1.3L - DTCS P0108 To P025C >> DTC Troubleshooting >> P0137: O2 Sensor 1/2 Circuit Low >> Diagnostic Test
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Diagnostic Test

  1. CHECK FOR AN ACTIVE DTC 
    1. With the scan tool, read Powertrain Control Module (PCM) DTCs and Freeze Frame Data and record on the repair order.
    2. Using the recorded Freeze Frame Data and the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
    3. With the scan tool, read PCM DTCs.

      Is the DTC active or pending?

      Yes 

      • Go To  2

      No 

  2. CHECK THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT 
    1. Turn the ignition off.
    2. Disconnect the O2 Sensor 1/2 harness connector.
    3. Turn the ignition on.
    4. With the scan tool, monitor the O2 Sensor 1/2 voltage.

      Is the O2 Sensor 1/2 voltage between 4.1 and 5.0 volts?

      Yes 

      • Verify that there is good pin to terminal contact in the O2 Sensor 1/2 and Powertrain Control Module connectors. If no problems are found, replace the O2 Sensor 1/1 in accordance with the Service Information. Refer to SENSOR, OXYGEN, REMOVAL AND INSTALLATION .
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  3
  3. CHECK THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT FOR A SHORT TO GROUND 
    1. Disconnect the PCM C1 harness connector.
    2. Check for continuity between ground and the (K141) O2 Sensor 1/2 Signal circuit at the O2 Sensor 1/2 harness connector.

      Is there continuity between ground and the (K141) O2 Sensor 1/2 Signal circuit?

      Yes 

      • Repair the (K141) O2 Sensor 1/2 Signal circuit for a short to ground.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  4
  4. CHECK FOR THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT FOR A SHORT TO THE (K904) O2 SENSOR 1/2 RETURN CIRCUIT 
    1. Check for continuity between the (K141) O2 Sensor 1/2 Signal circuit and the (K904) O2 Sensor 1/2 Return circuit in the O2 Sensor 1/2 harness connector.

      Is there continuity between the (K141) O2 Sensor 1/2 Signal circuit and the (K904) O2 Sensor 1/2 Return circuit?

      Yes 

      • Repair the (K141) O2 Sensor 1/2 Signal circuit for a short to the (K904) O2 Sensor 1/2 Return circuit.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  5
  5. CHECK FOR THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT SHORTED TO THE (K299) O2 SENSOR 1/2 HEATER CONTROL CIRCUIT 
    1. Check for continuity between the (K141) O2 Sensor 1/2 Signal circuit and the (K299) O2 Sensor 1/2 Heater Control circuit in the O2 Sensor 1/2 harness connector.

      Is there continuity between the (K141) O2 Sensor 1/2 Signal circuit and the (K299) O2 Sensor 1/2 Heater Control circuit?

      Yes 

      • Repair the (K141) O2 Sensor 1/2 Signal circuit for a short to the (K299) O2 Sensor 1/2 Heater Control circuit.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  6
  6. CHECK THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Measure the resistance of the (K141) O2 Sensor 1/2 Signal circuit from the O2 Sensor 1/2 harness connector to the PCM C2 harness connector.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  7

      No 

      • Repair the (K141) O2 Sensor 1/2 Signal circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  7. CHECK THE (K902) O2 SENSOR UPSTREAM RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Measure the resistance of the (K902) O2 Sensor Upstream Return circuit between the O2 Sensor 1/2 harness connector and the PCM C2 harness connector.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  8

      No 

      • Repair the (K902) O2 Sensor Upstream Return circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  8. CHECK RELATED PCM AND COMPONENT CONNECTIONS 
    1. Perform any Service Bulletins that apply.
    2. Disconnect all PCM harness connectors.
    3. Disconnect all related in-line harness connections (if equipped).
    4. Disconnect the related component harness connectors.
    5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
      • Proper connector installation.
      • Damaged connector locks.
      • Corrosion.
      • Other signs of water intrusion.
      • Weather seal damage (if equipped).
      • Bent terminals.
      • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
      • Terminals that have been pushed back into the connector cavity.
      • Check for spread terminals and verify proper terminal tension.

      Repair any conditions that are found.

    6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
    7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
    8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
    9. With the scan tool, erase DTCs.
    10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
    11. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      No 

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