Brake Lamp: Description and Operation

GF82.10-P-3010SK Stop Lamp Control, Function

Function requirements:
^ Circuit 15 ON
^ BAS release switch (A7/7s1) is operated

The transmitter key (A8/1) in the EIS control unit (N73) is in position "circuit 15 ON" and the service brake is operated. The BAS release switch (A7/7s1) is used to read in the stop light signal from the ESP and BAS control unit (N47-5).

The ESP and BAS control unit (N47-5) transmits the "stop lamps ON" message to the central gateway control unit (N93) via the Controller Area Network Bus Class C (engine compartment) (CAN-C), which forwards the message via the Controller Area Network Bus Class B (interior) (CAN-B) to the rear SAM control unit with fuse and relay module (N10/2).

At the same time the ESP and BAS control unit (N47-5) transmits the "stop lamps ON" message via a discrete line to the driver-side SAM control unit with fuse and relay module (N10/1) and 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) actuates the left stop lamp, taillamp and parking lamp (E3e9), the right stop lamp, taillamp and parking lamp (E4e9), and the center high-mounted stop lamp (E21) via a discrete line.

The discrete line from the ESP and BAS control unit (N47-5) to the rear SAM control unit with fuse and relay module (10/2) renders a fast transmission of the "stop lamps ON" message possible in comparison to a transmission via CAN-B.

The "stop lamps ON" message is, in addition to its actual task (stop lamps actuation), of significance for other functional ranges of the vehicle. Consequently, the "stop lamps ON" message is supplied by the central gateway control unit (N93) on the CAN-B.