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Diagnostic Test

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

    2. With the scan tool, read the O2 Sensor 1/2 signal voltage.

      Is the voltage staying above 4.0 volts?

      Yes 

      • Got to 2

      No 

  2. CHECK THE O2 SENSOR 1/2 HEATER OPERATION 
    1. With the scan tool, check the O2 Sensor 1/2 duty cycle and 1/2 heater temperature readings.
      NOTE:

      When a normally operating switching O2 Sensor is heated to operating temperature the typical duty cycle percentage should be between 30 and 50 percent. The typical heater temperature should range between approximately 1200°F and 1400°F on the scan tool. If there is an issue with the O2 Sensor heater or circuitry the PCM will disable the heater driver and the duty cycle will be 0 percent. Any issues in the heater circuitry, even a small amount of resistance, will cause the temperature reading to be noticeably different.

      Is the O2 Sensor heater operating properly?

      Yes 

      • Got to 7

      No 

      • Got to 3
  3. CHECK THE O2 SENSOR 1/2 (Z909) GROUND CIRCUIT FOR HIGH RESISTANCE BY LOAD TESTING THE CIRCUIT 
    NOTE:

    Read the CIRCUIT LOAD TESTING PROCEDURE for information on building a simple load test tool and for additional load testing information and alternative methods of load testing or voltage drop testing a circuit. Refer to CHECKING THE EXHAUST SYSTEM FOR LEAKS .

    1. Turn the ignition off.
    2. Disconnect the O2 Sensor 1/2 harness connector.
      CAUTION:

      Do not load test any circuits with components still connected to the circuit.

    3. Load test the O2 Sensor 1/2 (Z909) Ground circuit at the O2 Sensor 1/2 harness connector (A). Note:  refer to the diagram below.
      GC0174957Courtesy of CHRYSLER GROUP, LLC
      NOTE:

      The bulb on the load test tool should be illuminated and bright if there is no resistance in the circuitry. Compare the brightness of the bulb in the load test tool to that of a direct connection across Battery.

      Is the load test bulb illuminated and bright?

      Yes 

      • Got to 4

      No 

      • Repair the O2 Sensor 1/2 (Z909) Ground circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  4. CHECK THE O2 SENSOR 1/2 (K299) HEATER CONTROL CIRCUIT FOR A SHORT TO ANOTHER VOLTAGE SUPPLY CIRCUIT 
    1. Disconnect the PCM C2 harness connector.
      CAUTION:

      Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.

    2. Connect the (special tool #10436, Adapter, GPEC Diagnostic)to the appropriate PCM connector.
    3. Check for continuity between the O2 Sensor 1/2 (K299) Heater Control circuit and all other circuits at the GPEC Adaptor.

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

      Yes 

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

      No 

      • Got to 5
  5. CHECK THE O2 SENSOR 1/2 (K299) HEATER CONTROL CIRCUIT FOR A SHORT TO GROUND 
    1. Check for continuity between ground and the O2 Sensor 1/2 (K299) Heater Control circuit at the GPEC Adaptor.

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

      Yes 

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

      No 

      • Got to 6
  6. ISOLATE AND LOAD TEST THE O2 SENSOR 1/2 (K299) HEATER CONTROL CIRCUIT TO CHECK FOR HIGH RESISTANCE 
    NOTE:

    Read the CIRCUIT LOAD TESTING PROCEDURE for information on building a simple load test tool and for additional load testing information and alternative methods of load testing or voltage drop testing a circuit. Refer to CIRCUIT LOAD TESTING PROCEDURES .

    CAUTION:

    Do not load test any circuits with components still connected to the circuit.

    1. Load test the O2 Sensor 1/2 (K299) Heater Control circuit.
      GC0174954Courtesy of CHRYSLER GROUP, LLC
      NOTE:

      The bulb on the load test tool should be illuminated and bright if there is no resistance in the circuit. Compare the brightness of the bulb in the load test tool to that of a direct connection to Battery.

      Is the load test bulb illuminated and bright?

      Yes 

      • Got to 10

      No 

      • Repair the O2 Sensor 1/2 (K299) Heater Control circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  7. CHECK THE O2 SENSOR 1/2 (K141) SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE 
    1. Turn the ignition on, engine not running.
    2. Disconnect the O2 Sensor 1/2 harness connector.
    3. Measure the voltage on the O2 Sensor 1/2 (K141) Signal circuit at the O2 Sensor 1/2 harness connector.

      Is the voltage above 5.2 volts?

      Yes 

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

      No 

      • Got to 8
  8. CHECK THE O2 SENSOR 1/2 (K141) SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Disconnect the PCM C2 harness connector.
      CAUTION:

      Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.

    2. Connect the (special tool #10436, Adapter, GPEC Diagnostic)to the appropriate PCM connector.
    3. Measure the resistance of the O2 Sensor 1/2 (K141) Signal circuit between the O2 Sensor 1/2 harness connector and the GPEC Adaptor.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Got to 9

      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 .
  9. CHECK THE O2 SENSOR 1/2 (K904) RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Measure the resistance of the O2 Sensor 1/2 (K904) Return circuit between the O2 Sensor 1/2 harness connector and the GPEC Adaptor.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Got to 10

      No 

      • Repair the O2 Sensor 1/2 (K904) Return circuit for a an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  10. REPLACE THE O2 SENSOR 1/2 AND RETEST FOR DTC 
    1. Replace the O2 Sensor 1/2 in accordance with the Service Information. Refer to SENSOR, OXYGEN, REMOVAL AND INSTALLATION .
    2. Connect the O2 Sensor 1/2 and PCM harness connectors.
    3. Turn the ignition on.
    4. With the scan tool, erase DTCs.
    5. Using the recorded Freeze Frame and the When Monitored conditions, operate the vehicle in the conditions that set the DTC.
    6. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      • Got to 11

      No 

  11. 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 .
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