The steering wheel control switches control the following radio features:

Voltage is supplied to the RH steering wheel controls through the STG WHL CNTRL Fuse 3, circuit 243, the SIR coil assembly when the ignition switch is in ACCY, RUN or the RAP mode is active. The switches are a ladder network consisting of the switches and a series of resistors. The ladder network allows each switch to have a different resistance. The different resistances allow a different voltage output to the radio for each switch pressed.

Voltage is supplied to both steering wheel controls through the STG WHL CNTRL Fuse 13, circuit 1458, through the SIR coil assembly. Ground is supplied to both steering wheel controls from G200, circuit 650 through the SIR coil assembly. The steering wheel control (SWC) switches use incandescent backlighting. The illumination signal circuit 1458 is a pulse width modulated (PWM) signal from the headlight switch. The bulbs are serviceable.

The SIR Coil Assembly contains 6 wires, four of which are used by the SWC. The SWC allows voltage to be sent from the steering wheel switches to the radio while the steering wheel is being turned.