Test Description
WARNING: This page is about a different car, the 2002 Pontiac Grand Am, 2002 Oldsmobile Alero, 2002 Chevrolet Monte Carlo, and 2002 Chevrolet Impala. 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 procedures.
- 2
The HO2S 1 voltage may default to the bias voltage. The DTC should be cleared and the Freeze Frame/Failure Records data recorded before proceeding. A normally functioning HO2S 1 voltage signal will fluctuate greater than and less than 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 checks 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 checks 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 table may contribute to the failure of the HO2S. The conditions listed apply only to this type of failure.