GM Service Manual Online
For 1990-2009 cars only

Important: The following steps must be completed before using the symptom tables.

  1. Before using the symptom diagnostic table, perform the Diagnostic Trouble Code (DTC) List - Vehicle in order to verify the following conditions:
  2. • There are no DTCs set.
    • The module can communicate via the GM LAN.
  3. Review the system operation in order to understand the system functions. Refer to Cruise Control Description and Operation.

Visual/Physical Inspection

    • Inspect for aftermarket devices which can affect the operation of the Cruise Control System. Refer to Checking Aftermarket Accessories.
    • Inspect the accessible system components or the visible system components for obvious damage or for obvious conditions which can 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.

Symptom List

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

    •  Cruise Control Malfunction.
    •  Cruise Control Switch Indicator Inoperative