Brake light actuation, function - GF82.10-P-3010LE
MODEL 216.3, 221.0/1 as of model year 2009/YoM 08
Function requirements, brake light actuation, general
- Circuit 15 On
The circuit status of circuit 15 is provided by the EIS [EZS] control unit (N73) on the interior CAN (CAN-B).
Brake light actuation, general
Corresponding to the request the brake light actuation realizes a static or flashing actuation of the brake lights on the vehicle.
Brake light actuation is comprised of the following subfunctions:
- Function sequence, static brake lights
- Function sequence for adaptive brake lights (without code (494) USA version)
Function sequence, static brake lights
Actuation of the service brake is detected by the BAS release switch (A7/7s1) in the BAS brake booster (A7/7).
The ESP control unit (N47-5) (without model 221.095/195) or the regenerative braking system control unit (N30/6) (model 221.095/195) reads in the status of the BAS cancel switch directly and places it on the chassis CAN (CAN E).
The central gateway control unit (N93) routes this signal via the interior CAN to the rear SAM control unit with fuse and relay module (N10/2) and forwards it, for vehicles with code (550) Trailer hitch, to the trailer recognition control unit (N28/1).
At the same time the "brake light ON" (circuit 54) request is forwarded by the ESP or regenerative braking system control unit directly to the front SAM control unit with fuse and relay module (N10/1). Once there however, it is only looped through to the rear SAM control unit.
The rear SAM control unit routes the request straight to the trailer recognition control unit.
Direct actuation should counteract any delay in forwarding the "brake lights On" request via the chassis CAN and the interior CAN.
The rear SAM control unit actuates the following components:
- Left brake light, taillight and parking light (E3e9)
- Right brake light, taillight and parking light (E4e9)
- Center high-mounted stop lamp (E21)
The stop lamps and the center high-mounted stop lamp are also actuated if the electric parking brake switch (S76/15) is operated while driving.
The trailer recognition control unit actuates the corresponding components for the lighting system on the trailer through the trailer hitch socket, 13-pin (X58).
Additional function prerequisites for adaptive brake lights (without code (494) USA version)
- Brake operated
- Vehicle speed v > 50 km/h
- Brake Assist system active or vehicle deceleration a > 7.5 m/s2
- Manual hazard warning flashing inactive
Function sequence for adaptive brake lights (without code (494) USA version)
Information on vehicle speed is made available by the instrument cluster (A1) on the central CAN (CAN F).
In the event of hazard braking, the ESP control unit or regenerative braking system control unit sends a corresponding signal via the chassis CAN. The central gateway control unit routes all relevant information over the interior CAN to the rear SAM control unit and as of 1.6.09, forwards it to the trailer recognition control unit.
The rear SAM control unit actuates the brake lights and center high-mounted brake lamp for the duration of the signal (t 1 s) at a frequency of f = 5 to 7 Hz and also sends a corresponding signal via the interior CAN to the trailer recognition control unit, which defines the duration of the set dark phase.
The following frequencies are output on the trailer corresponding to the bulbs used:
- for incandescent bulbs, f = 3 Hz
- for LEDs, f = 5 Hz
The hazard warning flasher function is activated automatically when the vehicle finally comes to a stop.
The brake light and center high-mounted brake lamp are again actuated continuously.
The emergency braking signal is reset if one of the following conditions is complied with:
- Brake not operated
- Vehicle speed v < 10 km/h
- Brake Assist inactive and vehicle deceleration a < 6.5 m/s2 for at least t = 150 ms
| Electrical function schematic for brake light actuation | Model 216 | PE82.10-P-2057-97CAA | |
| Model 221 | PE82.10-P-2057-97SAA | ||
| Instrument cluster, component description | A1 Model 216.3, 221.0/1 except 221.095/195 |
GF54.30-P-6000LE | |
| Model 221.095/195 | GF54.30-P-6000LEH | ||
| Front SAM control unit with fuse and relay module, component description | N10/1 | GF54.21-P-6070LE | |
| Rear SAM control unit with fuse and relay module, component description | N10/2 | GF54.21-P-6030LE | |
| Trailer recognition control unit component description | N28/1 For model 221 with code (550) Trailer hitch |
GF31.19-P-4050LE | |
| Component description for regenerative braking system control unit | N30/6 On model 221.095/195 |
GF42.22-P-1100LEH | |
| ESP control unit, component description | N47-5 Except model 221.095/195 |
GF42.45-P-5118LE | |
| Component description for EIS [EZS] control unit | N73 | GF80.57-P-6003LE | |
| Central gateway control unit, component description | N93 | GF54.21-P-4170LE |