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Diagnostic Test

  1. CHECK FOR CONTAMINANTS OR DAMAGE TO THE O2 SENSOR 
    1. Check for contaminants that may have damaged the O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant.

      Are there contaminants that may have damaged the O2 Sensor present?

      Yes 

      No 

      • Go To  2.
  2. CHECK FOR AN ACTIVE DTC 
    1. Start the engine.
    2. Allow the engine 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.

    3. With a scan tool, read the active DTCs.
      NOTE:

      It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.

      Is the DTC active or pending?

      Yes 

      • Go To  3

      No 

  3. CHECKING THE EXHAUST SYSTEM FOR LEAKS 
    1. Perform the CHECKING THE EXHAUST SYSTEM FOR LEAKS test procedure. Refer to CHECKING THE EXHAUST SYSTEM FOR LEAKS .

      Were any exhaust leaks found?

      Yes 

      • Repair or replace the leaking exhaust parts as necessary.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  4
  4. CHECK THE O2 SENSOR VOLTAGE READINGS 
    NOTE:

    This DTC will set due to poor engine performance as well as a faulty O2 Sensor. If the vehicle exhibits any fuel system or driveability issues, or has any other driveability DTCs present, repair those concerns before proceeding with this test.

    NOTE:

    If the Powertrain Control Module detects an active open or short on any of the O2 Sensor 1/1 circuits, it will power down all of the O2 Sensor circuits to protect the O2 Sensor PCM internal ASIC from being damaged.

    1. Connect the (special tool #10367, Adapter, Wideband O2 Sensor Diagnostic) to the appropriate O2 Sensor harness.
    2. Turn the ignition on.
    3. Measure the voltages at the (K41) O2 Sensor Signal circuit and the (K902) O2 Sensor Return circuit at the Wide-band O2 Sensor Adapter.
      NOTE:

      The (K902) O2 Sensor 1/1 Return circuit voltage should read approximately 3.8 volts and the (K41) O2 Sensor 1/1 Signal circuit should read between approximately 3.35 volts and 4.25 volts if operating normally with no opens or shorts.

      Do the circuit voltages read as described?

      Yes 

      No 

      • Go To  5
  5. CHECK THE O2 SENSOR 1/1 CIRCUITS FOR A SHORT TO VOLTAGE 
    1. Turn the ignition off.
    2. Remove the Wide-band O2 Sensor Adapter, leaving the O2 Sensor harness disconnected.
    3. Turn the ignition on.
    4. Measure for voltage at the:
      • (K41) O2 Sensor 1/1 Signal circuit at the O2 Sensor 1/1 harness connector.
      • (K902) O2 Sensor 1/1 Return circuit at the O2 Sensor 1/1 harness connector.
      • (K89) O2 Sensor 1/1 Current Pump circuit at the O2 Sensor 1/1 harness connector.

      Do any of the circuits measure above 0.5 volts?

      Yes 

      • Repair the circuit that measured above 0.5 volts for a short to voltage.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  6
  6. CHECK THE O2 SENSOR 1/1 CIRCUITS FOR A SHORT TO GROUND 
    1. Turn the ignition off.
    2. 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.

    3. Connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM connector.
    4. Check for continuity between ground and the:
      • (K41) O2 Sensor 1/1 Signal circuit at the O2 Sensor 1/1 harness connector.
      • (K902) O2 Sensor 1/1 Return circuit at the O2 Sensor 1/1 harness connector.
      • (K89) O2 Sensor 1/1 Current Pump circuit at the O2 Sensor 1/1 harness connector.
      • (K79) O2 Sensor 1/1 Heater Control circuit at the O2 Sensor 1/1 harness connector.

      Is there continuity between any of the above circuits and ground?

      Yes 

      • Repair the circuit that measured above below 10k Ohms for a short to ground.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  7
  7. CHECK THE O2 SENSOR 1/1 CIRCUITS FOR AN OPEN OR HIGH RESISTANCE 
    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.

    1. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
    2. Measure the resistance of the:
      • (K41) O2 Sensor 1/1 Signal circuit between the O2 Sensor 1/1 harness connector and the GPEC Adaptor.
      • (K902) O2 Sensor 1/1 Return circuit between the O2 Sensor 1/1 harness connector and the GPEC Adaptor.
      • (K89) O2 Sensor 1/1 Current Pump circuit between the O2 Sensor 1/1 harness connector and the GPEC Adaptor.
      • (K79) O2 Sensor 1/1 Heater Control circuit between the O2 Sensor 1/1 harness connector and the GPEC Adaptor.

      Is the resistance below 3.0 Ohms? for each of the above circuits?

      Yes 

      • Go To  8

      No 

      • Repair the circuit that measured above 3.0 Ohms for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  8. CHECK THE O2 SENSOR OPERATION AND CONDITION 
    NOTE:

    Check for signs of contaminants that may have damaged the O2 Sensor, such as contaminated fuel, unapproved silicone, oil and coolant.

    1. Using the appropriate SYSTEM WIRING DIAGRAMS/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/1 and the Powertrain Control Module (PCM).
      • Look for any chafed, pierced, pinched, or partially broken wires.
      • Look for broken, bent, pushed out or corroded terminals.
      • Verify that there is good pin to terminal contact in the O2 Sensor 1/1 and Powertrain Control Module connectors.
      • Perform any Service Bulletins that may apply.

      Were any problems found?

      Yes 

      No 

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