Visual Inspection of HO2S
Visually/physically inspect following items:
Inspect the front HO2S for Contaminated, deteriorated or aged Front HO2S.
If contamination is evident on the HO2S, replace contaminated sensor.
Is the HO2S visually / physically O.K ?
YES
▶ Go to "Check Performance of H02S" 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
Connect scantool and Engine "ON"
Warm-up the engine to mormal engine temperature.
Monitor signal waveform of HO2S with scantool.
Specification : Voltage will vary between 0.1 and 0.9V.
Is the sensor switching properly ?
YES
▶ Go to "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
Connect Scantool and Engine "ON "
Select simulation function on scantool.
Simulate voltage at terminal "1" of HO2 sensor signal connector.
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 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.
