The steering wheel control switches duplicate the function of the primary controls of the associated component through a network of momentary contact switches. The body control module (BCM) supplies voltage to the audio steering wheel control momentary contact switches and monitors the return signal. Each switch is associated to a set resistance value. When a switch is pressed a specific voltage drops accross the resistor unique to the switch. The BCM identifies the selection and sends a serial data message to the component controlled by the switch, activating the switch selection

This section is intended to diagnosis the circuits between the BCM and the steering wheel control switches. If the primary control for the device is inoperative, refer to the appropriate section for the component.