Circuit/System Testing

WARNING: This page is about a different car, the 2008 Suzuki Swift +, 2008 Pontiac Wave, and 2008 Chevrolet Aveo. However, it is still accessible from the selected car via links, so may be relevant.

Ignition OFF, disconnect the harness connector at the appropriate HO2S.
Engine running, verify the scan tool HO2S parameter is between 350-500 mV.
- If less than the specifed range, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM.
Verify that none of the following conditions exist:
- Lean fuel injectors-Refer to Fuel Injector Balance Test with Special Tool .
- Water intrusion in the HO2S harness connector
- Low fuel system pressure-Refer to Fuel System Diagnosis .
- Fuel that is contaminated-Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
- Exhaust leaks near the HO2S
- Contaminated HO2S-Silicon
- Engine vacuum leaks
- If you find any of the above conditions, repair as necessary.
If all circuits test normal, test or replace the applicable HO2S.