Brake Light Actuation, Function - GF82.10-S-3010TRA
Model 447.6/7/8
except code XM0 (Facelift)
Model 448.7/8
Function requirements, general
- No overvoltage or undervoltage (operating voltage range from 8 to 17.5 V)
- "Circuit 15 ON"
The circuit 15 status is sent by the electronic ignition lock control unit (EZS) (N73) over the interior CAN (CAN B) to the signal acquisition and actuation module (SAM) control unit (N10/1).
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 service brake is operated, the status of the brake lights switch (S9/3) is read in directly by the Electronic Stability Program (ESP) control unit (N30/4).
If the brake lights switch is defective, braking is detected by the Electronic Stability Program (ESP) control unit through the brake pressure.
The Electronic Stability Program (ESP) control unit sends the brake lights request over the chassis CAN (CAN E), electronic ignition lock control unit (EZS) and the interior CAN to the signal acquisition and actuation module (SAM) control unit.
Brake light actuation on vehicles without CODE LG4 (LED taillights, brake lights and turn signal lights):
The signal acquisition and actuation module (SAM) control unit sends the brake lights actuation directly to the:
- The left rear lamp unit (E3), which then actuates the left taillight and left brake light (E3e4) directly.
- The right rear lamp unit (E4), which then actuates the right taillight and right brake light (E4e4) directly.
Brake light actuation on vehicles with CODE LG4 (LED taillights, brake lights and turn signal lights):
The signal acquisition and actuation module (SAM) control unit sends the brake lights actuation directly to the:
- The left rear LED lamp unit (E3/1), which then actuates the left brake light (E3/1e4) directly.
- The right rear LED lamp unit (E4/1), which then actuates the right brake light (E4/1e4) directly.
Center high-mounted brake lamp brake light actuation:
The signal acquisition and actuation module (SAM) control unit sends the brake lights actuation directly to the:
- Liftgate center high-mounted brake lamp (E21/2) (with code W65 (Liftgate))
- Center high-mounted brake lamp with rear window to be opened separately (E21/3) (model 447.8, model 448.8 with code W64 (Liftgate with big flip window))
- Rear-end door center high-mounted brake lamp (E21/1) (model 447.6/7 with code W50 (Two-wing rear-end door, 180 degrees without window) or code W54 (Two-wing rear-end door, 270 degrees))
If the parking brake and thus the electric parking brake indicator switch (S12/1) (model 447.8, model 448.8) or the parking brake indicator switch (S12) (model 447.6/7, model 448.7) is actuated while driving, all brake lights are actuated from a certain delay on.
The Electronic Stability Program control unit (ESP) reads in the status of the electric parking brake indicator switch or the parking brake indicator switch directly and sends this status via the chassis CAN, electronic ignition lock (EZS) control unit and interior CAN to the signal acquisition and actuation module (SAM) control unit.
On vehicles with CODE Q50 (Trailer hitch with removable ball head) or CODE Q22 (Trailer hitch with non-removable ball head):
The signal acquisition and actuation module (SAM) control unit forwards the brake light request to the trailer recognition (AAG) control unit (N28/1), which actuates the brake lights of the trailer via the 13-pin trailer socket (X58).
Function sequence for emergency braking
On model 447.8, model 448.8 with code ET4 (DISTRONIC PLUS):
If, at a vehicle speed of > 50 km/h, emergency braking (Brake Assist active) is initiated, all brake lights are actuated to flash on and off.
On model 447, model 448 without code ET4 (DISTRONIC PLUS):
If, at a vehicle speed of > 50 km/h, emergency braking (vehicle deceleration > 7.5 m/s2 ) is initiated, all brake lights are actuated to flash on and off.
The Electronic Stability Program (ESP) control unit sends the "Emergency braking" signal via the chassis CAN, electronic ignition lock (EZS) control unit, and interior CAN to the signal acquisition and actuation module (SAM) control unit. The signal acquisition and actuation module (SAM) control unit actuates the brake lights with a clock frequency of 3 or 5 Hz.
The following clock frequencies are output, depending on the light sources used:
- For bulbs 3 Hz
- For LEDs 5 Hz
On vehicles with code Q50 (Trailer hitch with removable ball head) or code Q22 (Trailer hitch with non-removable ball head), the signal acquisition and actuation module (SAM) control unit sends a signal via interior CAN to the trailer recognition (AAG) control unit (N28/1), which actuates the brake lights of the trailer via the 13-pin trailer socket.
The following clock frequencies are output, depending on the light sources used on the trailer:
- For bulbs 3 Hz
- For LEDs 5 Hz
If the vehicle comes to a standstill from a speed of > 70 km/h after emergency braking, the hazard warning flasher function is automatically activated.
The emergency braking signal is reset if one of the following preconditions is met:
- Vehicle speed = 0 km/h
- Vehicle deceleration < 6.5 m/s2
| Electrical function schematic for brake light actuation | Model 448.7/8 | PE82.10-S-2057-97VDA | |
| Model 447.6/7/8 except code XM0 (Facelift) | PE82.10-S-2057-97TRA | ||
| Overview of exterior lights system components | GF82.10-S-9998TRA |