Test Description
WARNING: This page is about a different car, the 2003 Pontiac Grand Prix, 2003 Chevrolet Malibu, and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers in the diagnostic procedure.
- 2 - A normally functioning HO2S 1 voltage signal will fluctuate above and below the bias voltage amount.
- 4 - A voltage reading other than the specified amount in this step indicates an open circuit condition in the high signal circuit or the PCM.
- 6 - This step tests the HO2S 1 signal circuits from the HO2S connector and the PCM connectors, including the low reference loop between the PCM connectors.
- 8 - This step tests for correct HO2S 1 heater circuit operation up to the HO2S connector. The heater low control is controlled by the PCM. The engine must be running to enable the HO2S heater.
- 9 - The conditions listed in the test may contribute to the failure of the HO2S. The conditions listed apply only to this type of failure.