Operation CHARM: Car repair manuals for everyone.

Light Switch Center

Light switch center
The light switch centre controls the entire exterior lighting system. The following components are integrated in the light switch centre, depending on equipment level.
^ Light switch
^ Switch for fog lamps
^ Dimmer control for dashboard, instrument cluster and locator lighting (terminal 58)
^ Photocell for detecting ambient light conditions





The light switch centre has the capability of adjusting the effective voltage at all outputs by means of pulse width modulation. With the exception of those for the bixenon headlights and their beam pattern screens, all output voltages are pulse width modulated.
Control of the effective voltage levels by pulse width modulation allows brightness fluctuations due to variations in the load on the vehicles electrical system to be evened out. The electrical system voltage has to be higher than the desired effective voltage.