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 .

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 in Wiring Systems.

  1. Speaker output open or shorted. Test the appropriate speaker output circuits for an open or short. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
  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 Radio Speaker Amplifier Replacement .
  3. Defective speaker. Replace the inoperative speaker. Refer to Speaker Replacement Reference .

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 in Wiring Systems.

  1. Low level audio signal circuit open or shorted. Test all low level audio signal circuits for an open or short. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
  2. No audio output from the CD changer. Test for AC voltage between the appropriate low level audio circuits at the amplifier connector, disconnected with the radio volume adjusted to an audible level. If AC voltage is present, replace the amplifier. Refer to Radio Speaker Amplifier Replacement . If no AC voltage is present, replace the CD changer. Refer to Remote CD Changer Replacement .

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 in Wiring Systems.

  1. Right or left audio signal circuit open or shorted. Test right and left audio signal circuits for an open or 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 Digital Radio Receiver Replacement .