Brake light actuation, function - GF82.10-P-3010GM

MODEL 164.1 as of model year 2009/YoM 08 model refinement package 

MODEL 164.8, 251.0/1 as of model year 2009/YoM 08 

Function requirements, brake light actuation, general 

• No overvoltage or undervoltage (operating voltage range U ≥ 7 ≤ 17.5 V)
• Circuit 15 ON

The circuit status is sent by the EZS control unit (N73) to 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, adaptive brake lights 

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) (except model 164.195) or the regenerative braking system control unit (N30/6) (model 164.195) directly reads in the status of the BAS release switch and sends it to the engine compartment CAN (CAN C).

The central gateway control unit (N93) routes this over the interior CAN to the rear SAM control unit (N10/8).

Parallel to this, the "Brake light ON" request (circuit 54) is forwarded from the ESP control unit straight to the rear SAM control unit, to counteract any delay in forwarding the request over the engine compartment CAN and the interior CAN.

The rear SAM control unit actuates the following components:

• Model 164.1 without code (849) Spare wheel holder/spare wheel
  • Left brake light (E3e4)
  • Right brake light (E4e4)
  • Center high-mounted brake lamp (E21)
• Model 164.8 without code (849) Spare wheel holder/spare wheel
  • Left brake light
  • Right brake light
  • Center high-mounted brake lamp
  • Left taillight, side marker lamp, parking light (E3e8)
  • Right taillight, side marker lamp, parking light (E4e8)
• Model 164 with code (849) Spare tire holder/spare tire
  • Left brake light and taillight (E3/5e4)
  • Right brake light and taillight (E4/5e4)
  • Center high-mounted brake lamp
• Model 251 up to 31.7.10
  • Left brake light, taillight, parking light, and side marker lamp (E3e9)
  • Right brake light, taillight, parking light and side marker lamp (E4e9)
  • Center high-mounted brake lamp
• Model 251 as of 1.8.10
  • Left brake light (E3e4)
  • Right brake light (E4e4)
  • Center high-mounted brake lamp
• Brake lights on trailer with code (550) Trailer hitch or code (553) Mechanically folding trailer hitch through trailer hitch socket, 13-pin (X58) (without code (460) Canada version or without code (494) USA version) or the trailer hitch socket, 7-pin (X58/11) (with code (460) Canada version or code (494) USA version)

Additional function requirements, adaptive brake lights 

• 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, adaptive brake lights 

The vehicle speed and deceleration are determined by the ESP control unit. In the event of danger braking the ESP control unit places a corresponding signal on the engine compartment CAN.

The central gateway control unit routes this signal over the interior CAN to the rear SAM control unit. The rear SAM control unit actuates the brake lights, the center high-mounted brake lamp and, if necessary, the brake lights on the trailer (with code (550) Trailer hitch or code (553) Mechanically folding trailer hitch) for the duration of the signal (at least t = 1 s) at a frequency of f = 7 Hz (with light-emitting diodes (LED) design) or f = 4 Hz (for bulb design).

If the vehicle comes to a standstill following emergency braking, the hazard warning flasher function is always automatically activated if braking occurred from a speed of v > 70 km/h.

The danger braking signal is reset if one of the following preconditions is met:

• Vehicle speed v < 5 km/h
• Vehicle deceleration a < 6.5 m/s2 for t = 150 ms

	Electrical function schematic for brake light actuation	Model 164	PE82.10-P-2057-97MAA
		Model 251	PE82.10-P-2057-97RAA
	Component description for rear SAM control unit	N10/8	GF54.21-P-7030GM
	Component description for regenerative braking system control unit	N30/6 On model 164.195 * for USA only	GF42.22-P-1100GQH
	Component description for ESP control unit	N47-5 Model 251, model 164 (except 164.195)	GF42.45-P-5118GM
	EZS control unit, component description	N73 Model 251, model 164 (except 164.195)	GF80.57-P-6003GM
		Model 164.195 * for USA only	GF80.57-P-6003GQH
	Component description for central gateway control unit	N93	GF54.21-P-4170GM