Actuation Module, LED Exterior Lighting, Front, Component Description - GF82.10-P-2160RDM
Model 172.4 as of model year 2017
with code 640 (High-performance LED)
with code 641 (Headlamps, LED, dynamic, left-side traffic)
with code 642 (Headlamps, LED, dynamic, right-side traffic)
Shown on model 172.4
Location
The left front exterior lights LED actuation module is mounted to the rear of the left front lamp unit. The right front exterior lights LED actuation module is mounted to the rear of the right front lamp unit.
Tasks
The front LED exterior lights actuation modules are responsible for the following tasks:
- Provision and monitoring of on-board electrical system voltage and operating current of the actuated LEDs
- Thermal management (temperature monitoring and fan control)
- Actuation of the LEDs in the corresponding front lamp unit to output the following light functions:
- Short range low beam
- Long range low beam
- High beam
The front LED exterior lights actuation modules actuate the LEDs located in the front lamp unit to implement the individual light functions.
In addition, the front LED exterior lights actuation modules actuate the following components:
- Left low beams (short range) (E1e15) or right low beams (short range) (E2e15)
- Left low beams (long range) and high beams (E1e16) and right low beams (long range) and high beams (E2e16)
The front actuation modules, LED exterior lighting are powered by the front SAM control unit with fuse and relay module (N10/1) (circuit 30L). The left front LED exterior lights actuation module communicates via left headlamp LIN (LIN G1) with the left headlamp control unit (E1n9). The right front LED exterior lights actuation module communicates via right headlamp LIN (LIN G2) with the right headlamp control unit (E2n9).
Identified malfunctions of individual components are stored in a non-volatile memory. The front LED exterior lights actuation modules can be diagnosed using the corresponding headlamp control unit.
The front actuation modules, LED exterior lighting are bolted to the front lamp unit housings. The front actuation modules, LED exterior lighting are connected to the vehicle-side wiring harness through the electrical connector on each front lamp unit.
Thermal management
The front lamp units are each equipped with a temperature sensor for each light function, which records heat development in the area of the actuated LEDs. The front LED exterior lights actuation modules evaluate the signals of two temperature sensors each.
If the LEDs or the plastic housings of the front lamp units threaten to overheat (as a consequence of excessively high outside temperatures or high actuation currents) the front actuation modules, LED exterior lighting reduce the actuation currents of the LEDs and therefore reduce the heat development.
Furthermore, the front actuation modules, LED exterior lighting actuate the following components to additionally cool the LEDs or plastic housings of the front lamp units:
- Left front lamp unit fan motor (E1m4) and right front lamp unit fan motor (E2m4)
The fan motors are either actuated immediately or with a time delay.
The actuation depends on which light function is active.
The active ventilation by means of actuation of the fan motors is used simultaneously for de-icing the front lamp units at low outside temperatures.
| Exterior lights wiring diagram | PE82.10-P-2000-97TAC |