Brake Lamp: Description and Operation

GF82.10-P-3010TM Stop Lamp Actuation, Function

Component Identification:

Requirements for operation:
^ Circuit 15 ON

Function
The transmitter key (A8/1) is in the EIS [EZS] control unit (N73) in position "2" (circuit 15 On) and the service brake is engaged. The switching contacts in the stop lamp switch (S9/1) are used to apply a voltage to the SBC control unit (A7/3n1), which then transmits a signal to the ESP control unit (N47-5) via the CAN bus for the brake system.
The ESP control unit (N47-5) signals "stop lamp On" by way of CAN class C to the central gateway control unit (N93). This signal is forwarded by CAN class B to the driver-side SAM control unit with fuse and relay module (N10/1) and rear SAM control unit wit fuse and relay module (N10/2).
At the same time, the SBC control unit (A7/3n1) routes the voltage signal via Circuit 54 straight on to the rear SAM control unit with fuse and relay module (N10/2).

The rear SAM control unit with fuse and relay module (N10/2) is connected via a discrete line to the SBC control unit (A7/3n1) and direct actuation should counteract any delayed forwarding of the stop light signal over the three CAN data buses. The rear SAM control unit with fuse and relay module (N10/2) actuates the left stop lamp (E3e4) and right stop lamp (E4e4) as well as the center high-mounted stop lamp (E21).
Next to its actual specified task, the actuation of the stop lamps, the stop lamp signal is also of significance for other functional areas in the vehicle. The stop light signal is therefore placed by the central gateway control unit (N93) onto CAN class B and CAN class C.
In vehicles with code (954) Avantgarde, an LED light source with 24 LEDs each is used for the brake lights. The center high-mounted stop lamp (E21) is always an LED light source in all models.

For vehicles with code (550) Trailer hitch, the signal "stop lamp On" is transmitted by the driver-side SAM control unit with fuse and relay module (N10/1) to the trailer connection unit [AAG] control unit (N28/1), which applies the signal "stop lamp On" to the trailer hitch socket (13-pin) (X58).