Substitute Lights And Emergency Lights Actuation, Function - GF82.10-P-3080RD
Model 172.4 up to model year 2017
Function requirements, general
- Terminal 15 ON
The electronic ignition switch control unit (N73) transmits the circuit status c. 15 via the interior CAN (CAN B).
Substitute lamp actuation/emergency light actuation, general
The substitute lamp actuation/emergency light actuation ensures operation of the minimum exterior lighting in the event of failure of individual system components for the vehicle's exterior lights.
The substitute lamp actuation/emergency light actuation consists of the following subfunctions:
- Function sequence for backup actuation (not on vehicles with code 498 (Japan version) or code 625 (Australia version) or code 830 (Additional parts for China vehicles))
- Function sequence for emergency light actuation
Function sequence for backup actuation (not on vehicles with code 498 (Japan version) or code 625 (Australia version) or code 830 (Additional parts for China vehicles))
The function of all lamps from the vehicle exterior lighting is checked. When the left rear turn signal light (E3e1) in the left rear lamp unit (E3) or the right rear turn signal light (E4e1) in the right rear lamp unit (E4) fails, its function is simulated by actuation of the outer left brake light and taillight (E3e11) or the outer right brake light and taillight (E4e11). With active backup actuation, the message "Substitute lights active" is shown in the multifunction display (A1p13) of the instrument cluster (A1). The corresponding request for this is sent by the rear SAM control unit with fuse and relay module (N10/2) via interior CAN to the instrument cluster.
| Actuation | failure | REPLACEMENT | Timing device |
|---|---|---|---|
| Rear turn signal and hazard warning flasher actuation | Left rear turn signal lights (E3e1) | Outer left brake light and taillight (E3e11) | No |
| Right rear turn signal lights (E4e1) | Outer right brake light and taillight (E4e11) | No |
Function sequence for emergency light actuation
The aim of the emergency lights actuation is to prevent a complete failure of the vehicle outside lights due to a processor failure or due to the failure of the interior CAN. For this reason, both the front SAM control unit with fuse and relay module (N10/1) and the rear SAM control unit have separate hardware which guarantees the emergency light function.
If the interior CAN, the front SAM control unit or the rear SAM control unit fails, the separate hardware in the front SAM control unit activates the front standing lights actuation and low beam actuation within t < 3 s. The separate hardware in the rear SAM control unit activates the rear standing lights actuation and, depending on the status of circuit 54, the brake light actuation.
| Overview of exterior lights system components | GF82.10-P-9998RD |