Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read DTCs.
  Is the DTC active?
  
  Yes
  - Go To 2
  No
  - Test complete.
CHECK THE POWERTRAIN CONTROL MODULE SOFTWARE LEVEL
1. Verify that the Powertrain Control Module software is up to date.
  Is the Powertrain Control Module software up to date?
  
  Yes
  - Go To 3
  No
  - Update the Powertrain Control Module software.
CHECK CONNECTIONS FOR POWERTRAIN CONTROL MODULE AND DOWNSTREAM O2 SENSOR
1. Check for the presence of loose electrical connections at the Powertrain Control Module and the Downstream O2 Sensor.
  Were any loose electrical connections present?
  
  Yes
  - Restore the correct connections.
  No
  - Go To 4
CHECK THE EXHAUST MANIFOLD FOR SEEPAGE
1. Check for the presence of seepage in the Exhaust Manifold.
  Is there seepage present in the Exhaust Manifold?
  
  Yes
  - Restore correct operation.
  No
  - Go To 5
CHECK CONDITION OF THE DOWNSTREAM O2 SENSOR
1. Check for the presence of any oil or oxidation on the sensitive element.
2. Check for the presence of any damage to the Downstream O2 Sensor casing.
  Is the Downstream O2 Sensor free of damage or contamination?
  
  Yes
  - Go To 6
  No
  - Clean the Downstream O2 Sensor.
CHECK THE INSTALLATION OF THE DOWNSTREAM O2 SENSOR
1. Check the installation of the Downstream O2 Sensor.
  Is the installation of the Downstream O2 Sensor correct?
  
  Yes
  - Go To 7
  No
  - Restore the correct installation of the Downstream O2 Sensor.
CHECK OPERATION OF THE DOWNSTREAM O2 SENSOR
1. Verify that the Downstream O2 Sensor is working correctly.
  Is the Downstream O2 Sensor working correctly?
  
  Yes
  - End of diagnosis.
  No
  - Replace the Downstream O2 Sensor. Refer to SENSOR, OXYGEN, REMOVAL AND INSTALLATION .