Brake Lamp: Description and Operation

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

Component Identification:

Basic requirements:
^ Circuit 15 ON

Function sequence
The ESP brake pressure sensor (B34) detects the brakes actuation and relays this information to the ESP and BAS control unit (N47-5).

The ESP and BAS control unit (N47-5) sends the "stop lamps ON" message via the class C (engine compartment) Controller Area Network Bus (CAN-C) to the EIS control unit (N73), which generates a class B (interior) Controller Area Network Bus (CAN-B) message from it and relays it to the rear SAM control unit with fuse and relay module (N10/2) via the CAN-B.

The rear SAM control unit with fuse and relay module actuates the left stop lamp (E3e4) in the left taillamp (E3) and the right stop lamp (E4e4) in the right taillamp (E4) and the center high-mounted stop lamp (E21) an.

At the same time the EPS and BAS control unit (N47-5) sends the stop lamp signal "circuit 54" via a discrete line to the front SAM control unit with fuse and relay module (N10/1) which relays it to the rear SAM control unit with fuse and relay module (N10/2).

Direct actuation by way of a discrete line is intended to compensate for any time delay in forwarding the stop lamp signal via the data busses.

In vehicles with code (550 Trailer hitch, the "stop lamp ON" message is transmitted by the rear SAM control unit with fuse and relay module (N10/2) to the trailer recognition control unit (N28/1) (via CAN-B and discretely), which actuates the 13-pin trailer hitch socket (X58).