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

Perform the Diagnostic System Check - Vehicle .

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 .

One Speaker Inoperative

  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 Control Module References .

  3. Audio output from the radio is not evident. 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. For the speaker testing location, refer to Speaker Replacement Reference . If AC voltage is not present, replace the radio. Refer to Radio Replacement .

All Speakers Inoperative

  1. Speaker output shorted--Test all speaker outputs for a short. Refer to Circuit Testing and Wiring Repairs .
  2. Antenna enable signal/amplifier control signal open--Refer to Circuit Testing and Wiring Repairs .
  3. Important: The radio must be programmed after replacement. Refer to Control Module References .

  4. Faulty radio--Replace the radio. Refer to Radio Replacement .