Speaker Circuit: Description
WARNING: This page is about a different car, the 2007 Lexus ES 350. However, it is still accessible from the selected car via links, so may be relevant.
The sound signal that has been amplified by the stereo component amplifier is sent to the speakers from the stereo component amplifier through this circuit.
If there is a short in this circuit, the stereo component amplifier detects it and stops output to the speakers. Thus, sound cannot be heard from the speakers even if there is no malfunction in the stereo component amplifier or speakers.