GM Service Manual Online
For 1990-2009 cars only

Important: Perform the Diagnostic System Check - Cruise Control Before using the symptom diagnostic table in order to verify that all of the following are true:

   • There are no DTCs set.
   • The control modules can communicate via the serial data link.
Review the system description and operation in order to familiarize yourself with the system functions. Refer to Cruise Control Description and Operation .

Visual/Physical Inspection

    • Inspect for aftermarket devices which could affect the operation of the Cruise Control System. Refer to Checking Aftermarket Accessories in Wiring Systems.
    • Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

    •  Cruise Control Indicator Inoperative
    •  Cruise Control Indicator Always On
    •  Cruise Control Inoperative/Malfunctioning