GM Service Manual Online
For 1990-2009 cars only

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

  1. Perform the Diagnostic System Check - Vehicle before using the Symptom Tables in order to verify that all of the following are true:
  2. • No DTCs are set.
    • The ability of the control module to communicate through serial data circuit
  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 could affect the operation of the radio. Refer to Checking Aftermarket Accessories .
    • Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent Conditions

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:

    •  Audio System Troubleshooting Hints
    •  Radio Poor Reception
    •  Noise Compensated Volume Inoperative
    •  Audio Distortion - One or More Speakers
    •  Noise Compensated Volume Inoperative
    •  Reduced Volume - One or More Speakers
    •  Speakers Inoperative - One or More
    •  Speakers Inoperative - All

For navigation related symptoms, refer to Symptoms - Navigation Systems .