Circuit/System Description
WARNING: This page is about a different car, the 2008 Buick Lucerne. However, it is still accessible from the selected car via links, so may be relevant.
The radio provides a radio audio mute signal circuit to control overall muting of remote non-serial data amplifiers. The amplifier receives PWM signals on the circuit at varying duty cycle percentages for controlling the muted and unmuted functions of the amplifier. A diagnostic sense circuit internal to the radio monitors the remote amp mute circuit for faults and sets the appropriate DTC when detected. The radio outputs a low duty cycle signal to produce an unmuted condition at the amplifier. The radio outputs a high duty cycle signal to produce a muted condition at the amplifier.