(Brake Light Actuation, Function - GF82.10-P-3010GR)
Model 166
up to Model year 2016
Function requirements, general
- No overvoltage or undervoltage
- Terminal 15 ON
The electronic ignition lock control unit (N73) transmits the status of circuit 15 via the interior CAN (CAN B) to the SAM control unit (N10).
Brake light actuation, general
The brake light actuation design can be adapted. In the event of emergency braking, the brake lights on the vehicle are actuated to flash on and off.
Brake light actuation function sequence
When the brake pedal is operated, the brake light switch (S9/1) is actuated.
The Electronic Stability Program control unit (N30/4) reads in the status of the brake light switch directly, uses it to generate a "Brake" request, implements this and transmits the status of the service brake via chassis CAN 1 (CAN E1), the electronic ignition lock control unit and the interior CAN to the SAM control unit and, in vehicles with CODE 550 (Trailer hitch), also to the trailer recognition control unit (N28/1).
The SAM control unit actuates the following components:
- Left brake light (E3e4) in the left rear lamp unit (E3)
- Right brake light (E4e4) in right rear lamp unit (E4)
- Center brake lamp (E21)
The trailer recognition control unit actuates the brake lights of the trailer via the trailer socket (X58) (except CODE 460 (Canada version) and except CODE 494 (USA version)) or via the 7-pin trailer socket (X58/11) (with CODE 460 (Canada version) or CODE 494 (USA version)).
In addition, the Electronic Stability Program control unit actuates the SAM control unit via a direct line (circuit 54) in order to counteract any delay in receiving the status of the service brake via the two data buses.
Model 166
up to Model year 2016
with CODE 550 (Trailer coupling)
There is also a direct connection (circuit 54) from the SAM control unit to the trailer recognition control unit.
The brake lights and center brake lamp are also actuated if the electric parking brake switch (S76/15) is pressed while driving.
The electric parking brake control unit (N128) reads in the status of the electric parking brake switch directly, and transmits the "Brake light On" request via chassis CAN 1, the electronic ignition lock control unit and the interior CAN to the SAM control unit, and in vehicles with CODE 550 (Trailer hitch), also to the trailer recognition control unit.
If, at a vehicle speed of v > 50 km/h, emergency braking (BAS active or vehicle deceleration a > 7.5 m/s2 ) is initiated, then the brake lights and the center brake lamp are actuated to flash on and off. The instrument cluster (A1) transmits the vehicle speed via the interior CAN to the SAM control unit. The Electronic Stability Program control unit sends the signal "Emergency braking" via chassis CAN 1, electronic ignition lock control unit and interior CAN to the SAM control unit and, on vehicles with CODE 550 (Trailer hitch), also to the trailer recognition control unit. The SAM control unit receives the "Emergency braking" signal, actuates the brake lights and the center brake lamp for the duration of the signal (t ≥ 1 s) with a frequency of f = 3 to 5 Hz and, in vehicles with CODE 550 (Trailer hitch), it then transmits an appropriate signal that defines the period for the configured dark phase via the interior CAN to the trailer recognition control unit. The trailer recognition control unit then actuates the trailer brake lights through the trailer socket.
The following frequencies are output according to the light sources used on the trailer:
- For bulbs, f = 3 Hz
- For light-emitting diodes, f = 5 Hz
If the vehicle comes to a standstill following emergency braking, the hazard warning flasher function is automatically activated if braking occurred from a speed of v > 70 km/h.
The CAN signal is reset if one of the following preconditions is met:
- Vehicle speed v < 10 km/h
- Vehicle deceleration a < 6.5 m/s2
| Electrical function schematic for brake light actuation | PE82.10-P-2057-97NAA | ||
| Overview of exterior lights system components | GF82.10-P-9998GR |