Cruise Control Inoperative/Malfunctioning: Notes

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

Important: To avoid misdiagnosis:

Inspect for proper operation of the brake lamps.
Inspect for proper operation of the transmission range switch.
Inspect throttle linkage for mechanical binding which could cause the system to malfunction.
Inspect cruise control adjustment, should have minimum slack.
Inspect for stored Diagnostic Trouble Codes (DTCs) in the PCM. Refer to xDIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS .
EMI on the speed sensor signal circuit may cause erratic cruise control operation.