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 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 4
- Check for the presence of any seepage in the Exhaust Manifold.
- O2 SENSOR CONDITION CHECK
- Check for the presence of any oil or oxidation on the sensitive element or damage to the sensor casing.
Sensor fouled or contaminated?
Yes
- Clean the O2 Sensor.
No
- Go To 5
- Check for the presence of any oil or oxidation on the sensitive element or damage to the sensor casing.
- CHECK OXYGEN SENSOR FITTING
- Check for proper fitting of the O2 Sensor.
Is the O2 Sensor fitted properly?
Yes
- Restore the correct fitting of the O2 Sensor.
No
- Go To 6
- Check for proper fitting of the O2 Sensor.
- 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.