GM Service Manual Online
For 1990-2009 cars only

Important: 

  1. Perform the Diagnostic System Check - Vehicle before using the Symptom Tables in order to verify that all of the following are true:
  2.    • There are no DTCs set.
       • The control modules 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 could affect the operation of the Entertainment System. Refer to Checking Aftermarket Accessories.
    • Inspect for 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.

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
    •  Digital Radio Poor or No Reception
    •  Radio Displays LOC, LOCKED, or CODE
    •  Radio Displays CLN or CLEAN
    •  Radio Displays CAL or CAL ERR
    •  Speed Compensated Volume
    •  Steering Wheel Controls Inoperative
    •  Reduced Volume - One or More Speakers
    •  Speakers Inoperative - One or More
    •  Radio Audio Inoperative at Rear Seat Audio (RSA) Control