Test Description

WARNING: This page is about a different car, the 2002 Oldsmobile Intrigue and 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step number in the diagnostic procedures.

2

This step checks for correct sensor activity. When in Closed Loop fuel control, the HO2S voltage should rapidly swing above and below the bias voltage.

4

This step checks the PCM and the high and low circuits between the PCM and HO2S connector for correct operation.

7

This step checks for correct HO2S heater circuit operation up to the HO2S connector.

8

This step checks for correct circuit resistance between the HO2S low reference circuits and the PCM ground.

13

This step checks for proper circuit resistance between the HO2S low reference circuits and PCM ground with a cold sensor. A loose HO2S or poor thread to exhaust electrical contact will cause higher resistance when the HO2S is cold. Although 500 ohms is allowed, typical resistance should be less than 50 ohms.