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 CONNECTIONS FOR POWERTRAIN CONTROL MODULE AND UPSTREAM O2 SENSOR
1. 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 THE UPSTREAM O2 SENSOR WIRING CONTINUITY
1. 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.
WIRING INSULATION CHECK
1. 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 EXHAUST MANIFOLD FOR LEAKS
1. Check that the Exhaust manifold for leaks.
  Are there Exhaust manifold leaks?
  
  Yes
  - Repair the Exhaust manifold leak.
  No
  - Go To 6
CHECK CONDITION OF THE UPSTREAM 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 Upstream O2 Sensor casing.
  Is the Upstream O2 Sensor free of damage or contamination?
  
  Yes
  - Go To 7
  No
  - Clean the Upstream O2 Sensor from foreign bodies.
CHECK OPERATION OF THE UPSTREAM O2 SENSOR
1. Check that the Upstream O2 Sensor is working properly.
  Is the Upstream O2 Sensor working properly?
  
  Yes
  - Go To 8
  No
  - Replace the Upstream O2 Sensor. Refer to SENSOR, OXYGEN, REMOVAL AND INSTALLATION .
CHECK OPERATION OF THE POWERTRAIN CONTROL MODULE
1. 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 .