Circuit Description
WARNING: This page is about a different car, the 2004 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.
This circuit sends the signal to the stereo component amplifier to mute the noise. Because of that, the noise produced by changing the sound source ceases.
In addition, this circuit is used to mute the sound when the navigation system performs voice guide.
If there is an open in the circuit, noise can be heard from the speaker when changing the sound source.
When the vehicle is equipped with the navigation system, audio sound keeps coming out from the speaker on the driver's side while the voice navigation is in operation.
If there is a short in the circuit, even though the stereo component amplifier assy is normal, no sound or only extremely small sound can be produced.