GM Service Manual Online
For 1990-2009 cars only

Schematic Reference: Radio/Navigation System Schematics

Connector End View Reference: Entertainment/Communication Connector End Views

Preliminary Information

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 to Connector Repairs .

Perform the Diagnostic System Check - Vehicle .

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 Circuit Testing and Wiring Repairs .

With RPO UQ7

  1. Battery positive voltage circuit to the amplifier open. Test the battery positive voltage circuit to the amplifier for an open. Refer to Circuit Testing and Wiring Repairs .
  2. Ground circuit to the amplifier open. Test the ground circuit to the amplifier for an open. Refer to Circuit Testing and Wiring Repairs .
  3. Important: With RPO Y91, Bose amplifier, perform the setup procedure for the amplifier. Refer to Audio Amplifier Setup .

  4. No audio output from the amplifier. Replace the amplifier. Refer to Radio Speaker Amplifier Replacement .

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 Circuit Testing and Wiring Repairs .

Without RPO UQ7

  1. Speaker output open. Test the appropriate speaker output circuits for an open. Refer to Circuit Testing and Wiring Repairs .
  2. Important: The radio must be programmed after replacement. Refer to Radio Setup .

  3. No audio output from the radio. Test for any AC voltage between the appropriate speaker output circuits at the speaker harness connector, disconnected with the radio volume adjusted to 50 percent. If AC voltage is present, replace the speaker. Refer to Speaker Replacement Reference . If no AC voltage is present, replace the radio. Refer to Control Module References .

With RPO UQ7

  1. Speaker output circuit from amplifier open. Test the appropriate speaker output circuits for an open. Refer to Circuit Testing and Wiring Repairs .
  2. Important: With RPO Y91, Bose amplifier, perform the setup procedure for the amplifier. Refer to Audio Amplifier Setup .

  3. 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 50 percent. 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 .

Speakers - One Channel 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 Circuit Testing and Wiring Repairs .

With RPO UQ7

    Important: With RPO Y91, Bose amplifier, perform the setup procedure for the amplifier. Refer to Audio Amplifier Setup .

  1. Speaker output circuit from amplifier shorted. Test the appropriate speaker output circuits for a short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs .
  2. Replace the amplifier. Refer to Radio Speaker Amplifier Replacement .

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

With RPO U2K

  1. Audio signal circuit open. Test the appropriate audio signal for an open. Refer to Circuit Testing and Wiring Repairs .
  2. No audio output from the digital radio receiver. Replace the digital radio receiver. Refer to Digital Radio Receiver Replacement and Digital Radio Receiver Setup .
  3. No digital output from the radio. Replace the radio. Refer to Control Module References .