Test Description

WARNING: This page is about a different car, the 2002 Pontiac Grand Prix, 2002 Chevrolet Malibu, and 2002 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 procedures.

2

The HO2S 2 should be allowed to cool before performing this test. The HO2S 2 is cool enough if the voltage output is stable at bias or about 450 millivolts. If the HO2S 2 heater is functioning, the signal voltage will gradually change as the sensor element warms. If the heater is not functioning, the HO2S 2 signal will remain near the 450 millivolts bias voltage or show very little activity.

4

This step ensures that the ignition voltage circuit to the HO2S 2 is not open or shorted. The test light must be connected to a good ground, independent of the HO2S system

6

This test must not be performed until the HO2S 2 heater has cooled and stabilized for at least 15 minutes. Heater resistance is typically about 5 ohms at room temperature.