Circuit Description
WARNING: This page is about a different car, the 2006 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.
This circuit sends a signal to the stereo component amplifier to mute noise. Because of that, the noise produced by changing the sound source ceases.
If there is an open in the circuit, noise can be heard from the speakers when changing the sound source. If there is a short in the circuit, even though the stereo component amplifier is normal, no sound, or only an extremely small sound, can be produced.