Hazard Warning Lamps: Description and Operation

GF82.10-P-3080TM Substitute/emergency Light Actuation, Function

Substitute lamp actuation

Function
The lamps of the exterior lights are continuously monitored for short circuits and open circuits.
If faulty, others are actuated as a replacement, if necessary by pulse width modulation.
The scope of the substitute lamp actuation depends on the national version.

Flashing functions have priority over continuous light.
An active automatic lamp substitution function is notified to the instrument cluster (A1) by the driver-side SAM control unit with fuse and relay module (N10/1), by the passenger-side SAM control unit (N10/11) or the rear SAM control unit with fuse and relay module (N10/2).

With model 211.2, the corresponding substitute lamp in the area of the rear-end door is actuated by the rear-end door control unit (N111).
The rear SAM control unit forwards the request to the rear-end door control unit.
If activation is successful, the rear-end door control unit forwards the "Substitute lights active" message to the instrument cluster.

Lamp failure indicator
A faulty bulb is indicated as text in the multifunction display (A1p13) of the instrument cluster.







Emergency lamp actuation
Function requirements:
^ Circuit 15 ON

Function
The emergency lamp actuation is intended to prevent any complete failure of the exterior lights by a fault, e.g. failure of a processor.
In case of failure of the Controller Area Network bus class B (interior) (CAN-B) fails or of an SAM control unit or of the trailer connection unit [AAG] control unit (N28/1) on vehicles with code (550) Trailer hitch, the following functions are activated within 3 s:
^ by the driver-side SAM control unit
- Left front standing lamp actuation
- Left front low beam actuation

^ by the passenger-side SAM control unit
- Right front standing lamp actuation
- Right front low beam actuation

^ by the rear SAM control unit (with model 211.0)
- Taillamp actuation at rear
- License plate illumination actuation

^ by the rear SAM control unit (with model 211.2)
- Taillamp actuation at rear by the rear-end door control unit (with model 211.2)
- License plate illumination actuation

^ by the trailer connection unit [AAG] control unit (with code (550) Trailer hitch)
- Trailer taillamp actuation