Headlamp Control Unit, Component Description - GF82.10-P-2020LFM

Model 222 as of model year 2018 with code 640 (SAE dynamic LED headlamps, right-hand traffic) 

Model 222 as of model year 2018 with code 641 (Dynamic LED headlamps, left-hand traffic) 

Model 222 as of model year 2018 with code 642 (Dynamic LED headlamps, right-hand traffic) 

Location 

The headlamp control units are located on the reverse side of the respective front lamp units.

The headlamp control units are tightly screwed to the housing of the respective front lamp units. The headlamp control units are connected to the vehicle-side wiring harness via the front lamp units.

Tasks 

The headlamp control units work in a master/slave combination and communicate with each other via the periphery CAN (CAN PER). As the master, the left headlamp control unit synchronizes the right headlamp control unit.

The headlamp control units have the following tasks:

• Read in sensors and signals 
• Evaluation of input factors 
• Controlling functions 
• Actuation of components 

Read in sensors and signals 

The input factors are read in via the following connections:

• Direct line 
• Peripherals CAN 

Direct line 

The left headlamp control unit reads in the signals of the following components via direct lines:

• Temperature sensors in left front lamp unit

The right headlamp control unit reads in the signals of the following components via direct lines:

• Temperature sensors in right front lamp unit

Peripherals CAN 

The headlamp control units read in the following function-relevant information via the periphery CAN, among other things:

• Variant coding
• Terminal status of terminal 15
• Signal engine running
• Drivetrain operational signal
• Light function request
• Vehicle level (only left headlamp control unit)
• Ambient data for Adaptive High Beam Assist

The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).

Evaluation of input factors 

The input factors that have been read in are evaluated by the integrated microprocessor and the relevant components are then actuated.

Controlling functions 

The headlamp control units actuate the following functions:

• Position lights
• Turn signal lamp
• High beams and headlamp flasher output
• Automatic headlamp range adjustment (HRA) (only left headlamp control unit)
• Cornering illumination
• Active curve illumination
• Active light distribution
• Thermal management (temperature monitoring)

The front lamp units have temperature sensors that are used to sense the heat development in the areas actuated by the LEDs. The headlamp control units evaluate the signals from the temperature sensors. If the LEDs or the plastic housings of the front lamp units threaten to overheat as a consequence of high outside temperatures or high actuation currents, the headlamp control units reduce the LED actuation currents and thereby the level of heat development. The front lamp units are also ventilated. The active ventilation is also used at the same time for thawing or deicing at low outside temperatures.

Actuation of components 

The actuation of the components takes place via the following connections:

• Direct line 
• Peripherals CAN 

Direct line 

The left headlamp control unit actuates the following components via direct lines:

• Left front turn signal lamp (E1e5)
• Left front side marker light (E1e6) (with CODE 460 (Canada version) or CODE 494 (USA version))
• Left cornering light (E1e9)
• Left infrared light (E1e11) (with code 610 (Night View Assist))
• Left front ambient light (E1e23) (only Economic Commission for Europe (ECE) vehicles)
• Left position light and daytime running light (E1e27)
• Left headlamp range adjustment actuator motor (E1m1)
• Fan motor 1 for left front lamp unit (E1 m4)

The right headlamp control unit actuates the following components via direct lines:

• Right front turn signal lights (E2e5)
• Right front side marker light (E2e6) (with CODE 460 (Canada version) or CODE 494 (USA version))
• Right cornering light (E2e9)
• Right infrared light (E2e11) (with code 610 (Night View Assist))
• Right front ambient light (E2e23) (only Economic Commission for Europe (ECE) vehicles)
• Right position light and daytime running light (E2e27)
• Right headlamp range adjustment actuator motor (E2m1)
• Fan motor 1 for right front lamp unit (E2m4)

Peripherals CAN 

The left headlamp control unit sends requests for high beam light distribution via the periphery CAN to the left front lamp unit LED matrix control unit (E1n11) and to the right front lamp unit LED matrix control unit (E2n11).

The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).

	Exterior lights wiring diagram	Headlamp unit E1	PE82.10-P-2000-97SEH
	Exterior lights wiring diagram	Headlamp unit E2	PE82.10-P-2000-97SEI