Circuit/System Description
The instrument panel module (IPM) supplies voltage to the multiple momentary contact switches and monitors the return signal. Each switch is associated to a set resistance value, when pressed a specific voltage drops across the resistors unique to the switch. The IPM identifies the selection, then sends a serial data message to the component controlled by the switch. If equipped with adaptive cruise control the Gap+/Gap- switches are in place of the mute/source switches and are in the same resistor ladder circuit.