For 1990-2009 cars only
Schematic Reference: Radio/Navigation System Schematics
Diagnostic System Check - Entertainment System
Always perform the Vehicle Diagnostic System Check before proceeding with these diagnostic procedures. Refer to Diagnostic System Check - Vehicle .
Speaker(s) - Reduced Volume/Audio Distortion
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 .
With RPO U1C
| • | Speaker output circuit high resistance or shorted to ground--Test the speaker output circuits for high resistance or short to ground. Refer to Circuit Testing and Wiring Repairs . |
| • | 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
| • | Audio common circuit open--Test the audio common circuit for an open. Refer to Circuit Testing and Wiring Repairs . |
| • | Speaker output circuit high resistance or shorted to ground--Test the speaker output circuits for high resistance or short to ground. Refer to Circuit Testing and Wiring Repairs . |
| • | No audio output from the digital radio receiver--Replace the digital radio receiver. Refer to Digital Radio Receiver Replacement and Digital Radio Receiver Setup . |
| • | No digital radio audio output from the radio--Replace the radio. Refer to Radio Replacement . |
