GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Reference Information

Schematic Reference

Radio/Navigation System Schematics

Connector End View Reference

Entertainment/Communication Connector End Views

Description and Operation

Radio/Audio System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Special Tools

J 39916-A CD and Cassette Diagnostic Audio Kit.

Circuit/System Verification

  1. Tune to a strong AM or FM station and verify each speaker is producing clear and even sound, with no distortion.
  2. ⇒If any speaker is not producing sound or the sound produced is distorted, refer to Speakers Inoperative - One or More.
  3. Clean the tape head path using J 39916-A CD and Cassette Diagnostic Audio Kit.
  4. Play a cassette and verify the radio does not display CLN or CLEAN.
  5. ⇒If the radio displays CLN or CLEAN, replace the radio.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for Radio replacement, setup, and programming