Diagnostic Procedure
- Check for any related TSBs.
Ignition on, engine not running.
With the DRBIII®, read DTCs and record the related Freeze Frame data.
Is the Good Trip Counter displayed and equal to zero?
- Yes --> Go To 2
- No --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure).
Perform POWERTRAIN VERIFICATION TEST VER - 5 .
- Start the engine.
Inspect the exhaust for leaks between the engine and the appropriate O2 Sensor.
Are there any exhaust leaks?
- Yes --> Repair or replace the leaking exhaust parts as necessary.
Perform POWERTRAIN VERIFICATION TEST VER - 5 .
- No --> Go To 3
- Yes --> Repair or replace the leaking exhaust parts as necessary.
- Turn the ignition off.
Backprobe the O2 Sensor Signal circuit at the O2 Sensor harness connector and PCM harness connector.
NOTE: Make sure the voltmeter leads are connected for positive polarity, meet the terminals in the connector, and that there is good terminal to wire connection.NOTE: Ensure the voltmeter leads are connected for positive polarityStart the engine.
Allow the engine to idle.
Is the voltage below 0.10 of a volt?
- Yes --> Go To 4
- No --> Repair the excessive resistance on the O2 Sensor Signal circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5 .
- Turn the ignition off.
Backprobe the (K4) Sensor ground circuit at the O2 Sensor harness connector and PCM harness connector.
NOTE: Make sure the voltmeter leads are connected for positive polarity, meet the terminals in the connector, and that there is good terminal to wire connection.Start the engine.
Allow the engine to idle.
Is the voltage below 0.10 of a volt?
- Yes --> Go To 5
- No --> Repair the excessive resistance in the (K4) Sensor ground circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5 .
- Turn the ignition off.
If there are no possible causes remaining, view repair.
- Repair
- Replace the O2 Sensor
- Perform POWERTRAIN VERIFICATION TEST VER - 5 .
- Repair