Substitute lights and emergency lights actuation, function - GF82.10-P-3080RC
MODEL 171.4 as of model year 09/YoM 08 model refinement package
Function requirements backup/emergency lights actuation in general Circuit 15 On
Backup/emergency lights actuation, general The backup/emergency lights actuation ensures the minimum exterior lighting if the event of failure of individual system components of vehicle exterior illumination.
The backup/emergency lights actuation is comprised of the following subfunctions: Function sequence for substitute lamp actuation; Function sequence, emergency lights actuation.
Function sequence for substitute lamp actuation The function of all the lamps in the vehicle's exterior lights are checked. If certain lamps fail, their function is reproduced through actuation of other lamps with pulse width modulation where applicable. In such an instance, flashing functions have priority over steady light.
An active automatic lamp substitution function is communicated to the instrument cluster (A1) from the driver SAM control unit with fuse and relay module (N10/1) or from the rear SAM control unit with fuse and relay module (N10/2) via the interior CAN. The instrument cluster (A1) shows the "Substitute lights active" message. The scope of the substitute lamp actuation is country-specific.
| Actuation | failure | Replacement | Timing device |
|---|---|---|---|
| Front parking lights actuation | Left standing and parking lights (E1e3) | Left front fog lamp (E5/1) | 100 Hz/25 % |
| Right standing and parking lights (E2e3) | Right front fog lamp (E5/2) | 100 Hz/25 % | |
| Rear standing lights actuation | Left brake light, taillight and parking light (E3e9) | Left rear fog light (E3e5) The right brake light, taillight and parking light E4e9) are also switched off and the right rear fog light (E4e5) is actuated. Right rear fog light |
100 Hz/25 % |
| Right brake light, taillight and parking light | The left brake light, taillight and parking light are also switched off and the left rear fog light is actuated. | 100 Hz/25 % | |
| Rear turn signal/hazard flasher actuation | Left turn signal lights (E3e1) | Left backup lamp (E3e3) | No |
| Right turn signal light (E4e1) | Right backup lamp (E4e3) | No | |
| Brake light actuation | Left brake light, taillight and parking light | Left rear fog light The right brake light, taillight and parking light are also switched off and the right rear fog light is actuated. | No |
| Right brake light, taillight and parking light | Right rear fog light The left brake light, taillight and parking light are also switched off and the left rear fog light is actuated. | No | |
| Rear fog light actuation | Left rear fog light | Left brake light, taillight and parking light (with left-hand drive vehicles) | No |
| Right rear fog light | Right brake light, taillight and parking light (with right-hand drive vehicles) | No |
Function sequence, emergency lights actuation The objective of the emergency lights actuation is to avoid any complete failure of the vehicle's exterior lights in the event of a processor failure or through failure of the interior CAN. To this end, both the driver SAM control unit and the rear SAM control unit have separate hardware, which guarantees the emergency light function.
In the event of a failure of the interior CAN or an SAM control unit, the front standing lights and low beams actuation are activated within a period t < 3 s from the separate hardware in the driver SAM control unit and the standing lights actuation is also activated and - depending on terminal status circuit 54 - the brake light actuation by the separate hardware in the rear SAM control unit.