Circuit/System Testing: Notes
WARNING: This page is about a different car, the 2007 Saturn Outlook. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT:
The DTC can be set by either the radio or the amplifier. If the DTC was set by the radio, diagnose suspect audio input circuits to the speakers or the amplifier (if equipped). Diagnose audio input signals to the speakers from the amplifier if the DTC was set by the amplifier.