Steering Wheel Controls Description and Operation

Steering Wheel Controls Description and Operation
The audio steering wheel control switches duplicate the function of the primary controls of the associated component, through a network of multiple momentary contact switches and a series of resistors. The radio supplies voltage to the switches and monitors the return signal for a specific voltage drop to occur unique to the one pressed. The radio identifies the switch selected to activate the feature, otherwise sends a serial data message that is received by the component controlled, activating the feature. The temperature up/down switch is part of this circuit, if equipped.

This information is intended to diagnosis the circuits between the radio and the audio steering wheel control switches. If the primary control for the device is inoperative, refer to the appropriate information for the component the steering wheel control switch is functioning.