GM Service Manual Online
For 1990-2009 cars only

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

  1. Perform Diagnostic System Check - Vehicle in Vehicle DTC Information before using the Symptom Tables in order to verify that all of the following conditions are true:
  2.    • There are no DTCs set.
       • The control module(s) can communicate via the serial data link.
  3. Review the system operation in order to familiarize yourself with the system functions. Refer to Radio/Audio System Description and Operation .

Visual/Physical Inspection

    • Inspect for aftermarket devices which may affect the operation of the Radio/Audio System. Refer to Checking Aftermarket Accessories in Wiring Systems.
    • Inspect for easily accessible or visible system components for obvious damage or conditions which may 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:

    •  Radio Poor Reception
    •  Digital Radio Poor or No Reception
    •  Audio Distortion - One or More Speakers
    •  Steering Wheel Controls Inoperative
    •  Speakers Inoperative - One or More
    •  Speakers Inoperative - All