Function Description

Function Description

The following control modules have a wire leading to the brake lamp switch (F):

• Engine Control Module

• Towing Recognition Control Module (J345)

• Comfort System Central Control Module (J393)

The brake lamp switch is now switched by the pedal bracket. The connected control modules read the switch condition. The engine control module is the master of this function and sends the brake lamp on command to the CAN data bus.

Braking also takes place via brake pressure sensor 1 (G201). When the brake pedal is pressed, brake pressure sensor 1 will transmit the brake pressure to the ABS control module (J104). The engine control module imports the information via the data bus and then transmits this brake lamp on command to all the other control modules via the data bus.

The control modules switch on the brake lamps as soon as the wire or the CAN data bus transmits the brake lamp on command. This assures that the brake lamps will function even if there is an interruption in the wires.

• The brake lamps are controlled by the comfort system central control module (J393).

• The brake lamps on a trailer are controlled by the towing recognition control module (J345). The trailer control module provide the voltage to the trailer socket for the brake lamps.