Diagnostic Test
- CHECK FOR AN ACTIVE DTC
- With the scan tool, read DTCs.
Is the DTC active?
Yes
- Go To 2
No
- Test complete.
- With the scan tool, read DTCs.
- CHECK CONNECTIONS FOR POWERTRAIN CONTROL MODULE AND UPSTREAM O2 SENSOR
- Check for the presence of loose electrical connections at the Powertrain Control Module and the Upstream O2 Sensor.
Were any loose electrical connections present?
Yes
- Restore the correct connections.
No
- Go To 3
- Check for the presence of loose electrical connections at the Powertrain Control Module and the Upstream O2 Sensor.
- CHECK THE UPSTREAM O2 SENSOR WIRING CONTINUITY
- Check the correct continuity of the Upstream O2 Sensor wiring.
Does the wiring have continuity?
Yes
- Go To 4
No
- Restore the correct continuity for the wiring.
- Check the correct continuity of the Upstream O2 Sensor wiring.
- WIRING INSULATION CHECK
- Check the correct insulation of the Upstream O2 Sensor wiring.
Were any faults with the Upstream O2 Sensor wiring insulation found?
Yes
- Restore the correct insulation for the wiring.
No
- Go To 5
- Check the correct insulation of the Upstream O2 Sensor wiring.
- CHECK OPERATION OF THE UPSTREAM O2 SENSOR
- Check that the Upstream O2 Sensor is working properly.
Is the Upstream O2 Sensor working properly?
Yes
- Go To 6
No
- Replace the Upstream O2 Sensor. Refer to SENSOR, OXYGEN, REMOVAL AND INSTALLATION .
- Check that the Upstream O2 Sensor is working properly.
- CHECK OPERATION OF THE POWERTRAIN CONTROL MODULE
- Verify that the Powertrain Control Module is working correctly.
Is the Powertrain Control Module working correctly?
Yes
- End of diagnosis.
No
- Replace the Powertrain Control Module. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL AND INSTALLATION .
- Verify that the Powertrain Control Module is working correctly.