Steering Wheel Switch - Message Center

The message center switch is part of the RH steering wheel switch and comprised of an upper switch (up and down toggle, return and OK) and lower switch (includes the HUD display control). The message center switch uses different resistance values associated with each button. 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 on the resistance of the specific button pressed, providing indication to the SCCM which button is pressed.