The brightness of the LC display fields is controlled by a phototransistor. When the vehicle lights are switched on, the brightness is controlled by way of the phototransistor and the dimmer setting.
The light-check module (LCM ) transfers the dimmer setting for the instrument lights and the indicator lamps in the form of a telegram on the body bus (K-bus ) and via the 58g line as a power signal to the instrument cluster.