GM Service Manual Online
For 1990-2009 cars only

Schematic Reference: Radio/Audio System Schematics

Connector End View Reference: Entertainment Connector End Views

Diagnostic System Check - Vehicle

Always perform the Diagnostic System Check - Vehicle before proceeding with these diagnostic procedures. Refer to Diagnostic System Check - Vehicle in Vehicle DTC Information

All Speakers Inoperative

Important: The following information lists the most probable cause of the concern to the least probable cause followed by the appropriate test for that condition. If the list leads to the replacement of a component, always inspect for a poor connection before proceeding with the replacement. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

All Radios

  1. Speaker output shorted--Test all speaker outputs for a short. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
  2. Defective radio--Replace the radio. Refer to Control Module References in Computer/Integrating Systems.

Important: The following procedure assumes all speakers are operative for all modes of operation except digital radio.

With RPO U2K

  1. Audio signal circuit shorted--Test the audio signal circuits for a short. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
  2. No audio output from the digital radio receiver--Replace the digital radio receiver. Refer to Control Module References in Computer/Integrating Systems.
  3. No digital radio audio output from the radio--Replace the radio. Refer to Control Module References in Computer/Integrating Systems.