Diagnostic Aids
WARNING: This page is about a different car, the 2002 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT:
Perform the following in order to avoid misdiagnosis.
- Inspect for proper operation of brake lamps.
- Inspect throttle linkage for mechanical binding which could cause the system to malfunction.
- Inspect cruise control cable adjustment, should have minimum slack.
- Inspect for stored Diagnostic Trouble Codes (DTCs) in the PCM.
- EMI on the speed sensor signal circuit may cause erratic cruise control operation.