Brake Light Actuation, Function - GF82.10-P-3010GN
Model 166
as of Model year 2016
Model 292
Function requirements, general
- No overvoltage or undervoltage (operating voltage range U ≥ 8 ≤ 17.5 V)
- Circuit 15 ON
The electronic ignition lock control unit (N73) sends the status of circuit 15 over 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 vehicles are actuated to flash on and off.
Brake light actuation function sequence
When the brake 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 receives this and 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 receives the status of the service brake and actuates the trailer brake lights via the trailer socket (X58) (without CODE 460 (Canada version) and without 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.
On vehicles with CODE 550 (Trailer hitch), a direct connection (circuit 54) also exists between 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) at a frequency of f = 3 to 5 Hz and, on vehicles with CODE 550 (Trailer hitch), transmits a corresponding signal that defines the period for the configured dark phase via 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, depending on the light sources used on the trailer:
- For bulbs, f = 3 Hz
- For LEDs 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 braking 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-2057-97NBA | ||
| Overview of exterior lights system components | GF82.10-P-9998GN |