Component Inspection
- Visually/physically inspect following items:
- Visually/physically inspect the front HO2S for contamination, deterioration, or damage.
- Inspect the front HO2S for any silicon contamination. This contamination will be indicated by a white powdery coating and this will result in a but false voltage signal.
- If contamination is evident on the HO2S, replace contaminated sensor and go to next step.
- Warm up the engine to normal operating temperature and check that HO2S signal is active.
- Connect Scantool and monitor the "O2 SNSR VOLT (B1/S1)" parameter on the Scantool data list.
Test Condition: Engine "ON" & In Closed loop mode.
- Signal decreases with rich air/fuel mixture and increases with lean air/fuel mixture.
- Fuel cut-off mode (PCM will stop the fuel supply when release the accelerator pedal suddenly after engine running about 4000 rpm): Approx. 3.2V
A: Acceleration, B: Declaration, C: Fuel Cut-off mode
- Is sensor data near the specified value?
YES
- Check for poor connection between PCM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO
- Check HO2S for contamination, deterioration, or damage. Substitute with a known-good HO2S and check for proper operation. If the problem is corrected, replace HO2S and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.