Steering Wheel Switch-Message Center

Message center functions are controlled through the up, down, back, settings and DISP buttons in the RH steering wheel switch. The RH steering wheel switch uses different resistance values associated with each specific button (up, down, back, OK, DISP and settings). The SCCM sends out a reference voltage to the RH steering wheel switch on the input circuit and monitors the voltage drops. The voltage drop varies depending upon the resistance of the specific button pressed, providing indication to the SCCM which button is pressed.