Reduced Volume - One or More Speakers for Pontiac Grand Am 2005

Schematic Reference: Radio/Audio System Schematics

Connector End View Reference: Entertainment Connector End Views

Always perform the Diagnostic System Check - Vehicle before proceeding with these diagnostic procedures. Refer to Diagnostic System Check - Vehicle in Vehicle DTC 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 Connector Repairs in Wiring Systems.

With RPO UQ2

1. Speaker output circuit high resistance--Test the appropriate speaker output circuits for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
2. Defective speaker--Replace the appropriate speaker. Refer to Speaker Replacement Reference .

With RPO U85

1. Speaker output circuit high resistance--Test the appropriate speaker output circuits for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
2. Gain control signal circuit short to ground--Test the gain control signal circuit for a short ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
3. Low level audio circuit open--Test the appropriate low level audio circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
4. Defective speaker--Replace the appropriate speaker. Refer to Speaker Replacement Reference .

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

With RPO U2K or U2L

1. Audio common circuit open or short to battery positive voltage--Test the audio common circuit for an open or short to battery positive voltage. 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 Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
3. No digital radio audio output from the radio--Replace the radio. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.