Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the appropriate HO2S 2.
- Ignition ON, verify that the HO2S parameter is between 400-520 mV.
- If greater than the specified range, test the signal circuit of the HO2S sensor for a short to the heater circuit. If the circuit/connections test normal, replace the ECM.
- If all circuits/connections test normal, replace the appropriate HO2S 2.