Component Inspection

Visual Inspection of HO2S.
1. Visually/physically inspect following items:
  1. Inspect the front HO2S for Contaminated, deteriorated or aged Front HO2S.
  2. If contamination is evident on the HO2S, replace contaminated sensor.
2. Is the HO2S visually/physically OK?
  YES
  - Go to " 2 Check Performance of HO2S" as below.
  NO
  - Substitute with a known - good HO2S and check for proper operation.
  - If the problem is corrected, replace HO2S and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Check performance of HO2S.
1. Connect scantool and Engine "ON".
2. Warm-up the engine to normal engine temperature.
3. Monitor signal waveform of HO2S with scantool.
  Specification: Voltage will vary between 0.1 and 0.9V.
  
  Fig 1: Monitoring Signal Waveform Of HO2S On Scantool
4. Is the sensor switching properly?
  YES
  - Go to " 3 Check PCM" as below.
  NO
  - Substitute with a known - good HO2S and check for proper operation.
  - If the problem is corrected, replace HO2S and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Check PCM.
1. Connect Scantool and Engine "ON".
2. Select simulation function on scantool.
3. Simulate voltage at terminal "1" of HO2 sensor signal connector.
  
  Fig 2: Simulating Voltage At Terminal 1 Of HO2 Sensor Signal Connector
4. Does the HO2 sensor signal value changes according to simulation voltage?
  YES
  - Fault is intermittent caused by poor contact in the sensor's and/or PCM's connector. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
  NO
  - Substitute with a known - good PCM and check for proper operation.
  - If the problem is corrected, replace PCM and go to "VERIFICATION OF VEHICLE REPAIR " procedure.