Diagnostic Test
- 1) CHECK FOR CURRENT DTC
Turn the ignition on.
With the scan tool, read PCM DTCs.
Is this DTC present?
Yes
- Go to 3).
No
- Go to 2).
- 2) INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors specific to this DTC. Wiggle the wires while checking for shorts and open circuits.NOTE: Check for any Technical Service Bulletins that may apply.Were there any problems found?
Yes
- Repair as necessary.
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .
No
- The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.
- 3) JUMPER THE 2/1 O2 SENSOR
Turn the ignition off.
Disconnect the 2/1 O2 Sensor harness connector.
NOTE: Check connectors - Clean/repair as necessary.Turn the ignition on.
Connect a jumper wire between ground and the 2/1 O2 Sensor Signal circuit.
With the scan tool, monitor the 2/1 O2 Sensor Signal voltage.
Does the O2 Sensor voltage drop to 0 volts?
Yes
- Go to 5).
No
- Go to 4).
- 4) SENSOR GROUND CIRCUIT OPEN
Turn the ignition off.
Remove the jumper wire.
Disconnect the PCM harness connectors.
NOTE: Check connectors - Clean/repair as necessary.Measure the resistance of the Sensor Ground circuit from the O2 Sensor harness connector to the PCM harness connector.
Is the resistance below 5.0 ohms?
Yes
- Inspect for the following before replacing the O2 Sensor.
- Fuel contamination.
- Engine oil or coolant consumption.
- Use of improper RTV sealant.
- Replace the Oxygen Sensor if none of the above conditions are present. Refer to REMOVAL .
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .
No
- Repair the excessive resistance in the Sensor Ground circuit.
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .
- Inspect for the following before replacing the O2 Sensor.
- 5) O2 SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE
Remove the jumper wire.
With the scan tool, monitor the 2/1 O2 Sensor Signal voltage.
Is the O2 Sensor voltage above 5.0 volts?
Yes
- Repair the short to voltage in the 2/1 O2 Sensor Signal circuit.
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .
No
- Replace and program the Powertrain Control Module. Refer to REMOVAL .
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .