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 O2 SENSOR
- Check for the presence of loose electrical connections at the Powertrain Control Module and the 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 O2 Sensor.
- CHECK THE O2 SENSOR WIRING CONTINUITY
- Check the correct continuity of the wiring between the O2 Sensor and the Powertrain Control Module.
Does the wiring have continuity?
Yes
- Go To 4
No
- Restore the correct continuity for the wiring.
- Check the correct continuity of the wiring between the O2 Sensor and the Powertrain Control Module.
- CHECK O2 SENSOR WIRING FOR A SHORT TO GROUND
- Check the correct insulation of the wiring between ground and the O2 Sensor.
Was the wiring shorted to ground?
Yes
- Restore the correct insulation for the wiring.
No
- Go To 5
- Check the correct insulation of the wiring between ground and the O2 Sensor.
- CHECK ON SEEPAGE IN EXHAUST MANIFOLD
- Check for the presence of any seepage in the Exhaust Manifold.
Seepage inside the Exhaust Manifold?
Yes
- Restore correct operation.
No
- Go To 6
- Check for the presence of any seepage in the Exhaust Manifold.
- CHECK OPERATION OF THE OXYGEN SENSOR
- Check that the O2 Sensor is working properly.
Is the O2 Sensor working properly?
Yes
- End of diagnosis.
No
- Replace the O2 Sensor. Refer to SENSOR, OXYGEN, REMOVAL AND INSTALLATION .
- Check that the O2 Sensor is working properly.