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Home >> Jeep >> 2024 >> Gladiator Nighthawk, Part Time T/Case Control, Automatic Trans >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> 3.6L (GPEC 2A) - DTCS P0032 To P0073 >> DTC Troubleshooting >> P0051-O2-Sensor 2/1 Heater Circuit Low >> Diagnostic Test
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Diagnostic Test

  1. CHECK FOR ANY SERVICE BULLETINS OR PCM SOFTWARE UPDATES 
    1. Check for any applicable Service Bulletins or Flash updates related to the DTC.

      Are there any applicable Service Bulletins or Flash updates?

      Yes 

      No 

      • Go To  2
  2. READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN 
    1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
    2. For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
    3. With the scan tool, erase all DTCs.
    4. Turn the ignition off for a minimum of 10.0 seconds.
    5. Turn the ignition on.
    6. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
    7. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      • Go To  3

      No 

  3. ISOLATE AND CHECK THE O2 SENSOR 2/1 (K199) HEATER CONTROL CIRCUIT FOR A SHORT TO GROUND 
    1. The ignition must be off when checking a circuit for continuity to ground.
    2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and every component harness connector containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
    3. Connect the negative lead of the DVOM to a known good ground.
    4. With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.
      NOTE:

      There should be no continuity between ground and the circuit being tested.

      Is there continuity between ground and the circuit being tested?

      Yes 

      • Repair the O2 Sensor 2/1 (K199) Heater Control circuit for a short to chassis ground or the O2 Sensor (Z909) Ground circuit. Use the wiring diagram as a guide to trace the circuit and look for any in-line connectors to help isolate the location of the short.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  4
  4. CHECK THE O2 SENSOR 2/1 HEATER CONTROL CIRCUIT 
    1. Turn the ignition off.
    2. Reconnect the PCM harness connector.
    3. Turn the ignition on.
    4. With the scan tool, actuate the O2 Sensor 2/1 control to the maximum allowable percentage.
    5. Using a 12-volt test light connected to ground, probe the O2 Sensor 2/1 (K199) Heater Control circuit at the O2 Sensor 2/1 harness connector.
      NOTE:

      The test light should be illuminated. The brightness will be dependant on the actuation percentage selected.

    6. With the scan tool, actuate the O2 Sensor 2/1 control to the OFF (0%) position.
    7. Using a 12-volt test light connected to ground, probe the O2 Sensor 2/1 (K199) Heater Control circuit at the O2 Sensor 2/1 harness connector.
      NOTE:

      The test light should not be illuminated.

      Does the test light illuminate with the actuator ON and not illuminate with the actuator OFF?

      Yes 

      No 

      • Go To  5
  5. 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 

      • The wiring or poor connection problem has been repaired.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .