For 1990-2009 cars

Schematic Reference: Radio/Audio System Schematics

Connector End View Reference: Entertainment/Communication 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.

### All Seat 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.

Seat speaker outputs from Amplifier shorted--Test the seat speaker outputs for a short to ground or to voltage. Refer to Circuit Testing and Wiring Repairs.

### Left and Right I/P Speakers Inoperative

Front speaker outputs from the Amplifier shorted--Test the Left and Right Front Speaker Output circuits for a short to ground or to voltage. Refer to Circuit Testing and Wiring Repairs.

### 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 the 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 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. 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.