GM Service Manual Online
For 1990-2009 cars only

Schematic Reference: Radio/Audio System Schematics

Connector End Views Reference: Entertainment Connector End Views

Diagnostic System Check - Vehicle

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

All Speakers on One Channel 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 .

  1. Low level audio signal circuit open or shorted--Test all low level audio signal circuits between the radio and audio amplifier for an open or short. Refer to Circuit Testing and Wiring Repairs .
  2. Right channel inoperative with Bose--Test the right rear door speaker output circuits for a short. Refer to Circuit Testing and Wiring Repairs .
  3. No audio output from the amplifier--Replace the amplifier. Refer to Control Module References .

All Speakers on One Channel Inoperative Only on Digital Radio

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 .

  1. Right or left audio signal circuit open or shorted--Test the appropriate audio signal circuits between the DRR and the radio for an open or short. Refer to Circuit Testing and Wiring Repairs .
  2. No audio output from the digital radio receiver--Replace the digital radio receiver. Refer to Control Module References .

One Speaker Inoperative

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

  1. Speaker output open or shorted--Test the appropriate speaker output circuits from the audio amplifier for an open or short. Refer to Circuit Testing and Wiring Repairs .
  2. No audio output from the amplifier--Test for any AC voltage between the appropriate speaker output circuits at the speaker harness connector, disconnected with the radio volume adjusted to an audible level. If AC voltage is present, replace the speaker. Refer to Speaker Replacement Reference . If no AC voltage is present, replace the amplifier. Refer to Control Module References .
  3. Defective speaker--Replace the inoperative speaker. Refer to Speaker Replacement Reference .