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Home >> Jeep >> 2016 >> Renegade Trailhawk >> Repair and Diagnosis >> Engine Performance >> System >> 2.4L - DTCS B104D To P0461 >> DTC Troubleshooting >> P0037-O2 Sensor 1/2 Heater Circuit Low >> Diagnostic Test
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Diagnostic Test

  1. CHECK FOR AN ACTIVE DTC 
    1. 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 may result in possible serious or fatal injury.

    2. With the scan tool, read DTCs and record on the repair order.

      Is the DTC active or pending?

      Yes 

      • Go To  2

      No 

  2. CHECK THE (K299) O2 SENSOR 1/2 HEATER CONTROL CIRCUIT FOR A SHORT TO GROUND 
    1. Turn the ignition off.
    2. Disconnect the Oxygen Sensor 1/2 harness connector.
    3. Disconnect the PCM C2 harness connector.
    4. Check for continuity between ground and the (K299) O2 Sensor 1/2 Heater Control circuit in the Oxygen Sensor 1/2 harness connector.

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

      Yes 

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

      No 

      • Go To  3
  3. CHECK THE (K299) O2 SENSOR 1/2 HEATER CONTROL CIRCUIT FOR A SHORT TO THE (Z909) GROUND CIRCUIT 
    1. Check for continuity between the (K299) O2 Sensor 1/2 Heater Control circuit and the (Z909) Ground circuit in the Oxygen Sensor 1/1 harness connector.

      Is there continuity between the (Z909) ground circuit and the (K299) O2 Sensor 1/2 Heater Control circuit?

      Yes 

      • Repair the short between the (K299) O2 Sensor 1/2 Heater Control circuit and the (Z909) Ground circuit.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  4
  4. OXYGEN SENSOR 1/2 
    1. Reconnect the PCM C2 harness connector.
    2. Turn the ignition on.
    3. With the scan tool, actuate the Oxygen Sensor 1/2 control to the maximum allowable percentage.
    4. Using a 12-volt test light connected to ground, check the (K299) O2 1/2 Heater Control circuit in the Oxygen Sensor 1/2 harness connector.
      NOTE:

      The test light should flash dimly.

    5. With the scan tool, actuate the Oxygen Sensor 1/2 control to the OFF (0%) position.
    6. Using a 12-volt test light connected to ground, check the (K299) O2 1/2 Heater Control circuit in the Oxygen Sensor 1/2 harness connector.
      NOTE:

      The test light should not be illuminated.

      Does the test light flash dimly with the actuator ON (25%) and not illuminated with the actuator OFF (0%)?

      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 

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