Mute Signal Circuit between Radio Receiver and Multi-media Interface ECU (FROM 12/2010): Description
WARNING: This page is about a different car, the 2011 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
The multi-media interface ECU sends a mute signal to the radio receiver assembly.
The radio receiver assembly controls the volume according to the mute signal from the multi-media interface ECU.
The mute signal is sent to reduce noise and popping sounds generated when switching modes.
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 radio receiver assembly is functioning, no sound, or only an extremely faint sound, can be heard.