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Headlamp control, function - GF82.10-P-2009TMA

MODEL 211.0 /2 as of 1.6.06 except CODE (494) USA version except CODE (498) Japan version with CODE (614) Bi-xenon headlamp unit with CODE (618) Bi-xenon headlamps with CODE (621) Intelligent Light System (left-hand traffic) with CODE (622) Intelligent Light System (right-hand traffic) 

MODEL 211.0 /2 as of 1.7.06 with CODE (494) USA version with CODE (614) Bi-xenon headlamp unit with CODE (622) Intelligent Light System (right-hand traffic) 

MODEL 211.0 /2 as of 1.7.06 with CODE (498) Japan version with CODE (614) Bi-xenon headlamp unit with CODE (618) Bi-xenon headlamps with CODE (621) Intelligent Light System (left-hand traffic) 

Fig 1: Networking Of Headlamp Control Components
G07504482Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Low beam, high beam, daytime running lamps, automatic headlamps actuation 

Low beam actuation 

Function requirements 

Function 

The driver-side SAM control unit reads in the rotary light switch position, places the request on CAN-B and simultaneously forwards it to the xenon headlamp control unit on the left front lamp unit (E1).

The front passenger-side SAM control unit detects the request over CAN-B and forwards it to the xenon headlamp control unit on the right front lamp unit (E2).

The xenon headlamp control units then actuate the respective bi-xenon lamp.

IMPORTANT The standing lamps remain actuated when the low beam is switched on. If the transmitter key (A8/1) is removed and the driver door opened, a lights-on warning is issued by the instrument cluster.

High-beams actuation 

Function requirements 

High beam function 

Headlamps actuation is requested by pressing the combination switch forwards.

The steering column module detects the position of the combination switch and places the request on the CAN-B. Detected by the driver-side SAM control unit, it is then sent over CAN-B to the central gateway control unit. From there, the request is placed on the CAN-D and thus made available to the Xenon headlamp control units. These in turn actuate over LIN the light distribution cylinder motors in the front lamp units, whereby the entire light beam is released for illumination of the road.

Additionally, the left high beam is actuated by the driver-side SAM control unit and the right high beam by the front passenger-side SAM control unit. The instrument cluster receives the "headlamps actuation active" status message over CAN-B and actuates the blue high beam indicator lamp.

Headlamp flasher function 

In contrast to the high beam function request, the combination switch is pulled backwards and held in this position. The function sequence and signal path for the headlamp flasher function are identical to the high beam function.

The high beam actuation remains active for as long as the combination switch is held in the headlamp flasher position.

IMPORTANT When the low-beam function is switched off, only the left high beam and right high beam are switched on; it would take too long to switch on the bi-xenon lamps.

Daytime running lamps actuation 

Function requirements 

Function 

The instrument cluster sends the status of the daytime running lamps function over CAN-B to the following control units:

IMPORTANT The daytime running lamps have a higher priority than the automatic headlamps actuation.

In countries with statutory daytime running lamp regulations, only the headlamp flasher is permitted in daytime running lamp mode, but not the high beam. High beam is only permissible if the headlamps have been manually switched on using the rotary light switch.

Actuations 

Automatic headlamp actuation 

Function requirements 

Function as at start of journey: 

Function as at end of journey: 

Function while driving 

The overhead control panel control unit evaluates the rain/light sensor signals. If darkness is detected, the request is sent over CAN-B to the driver-side SAM control unit and forwarded from there to the front passenger-side SAM control unit, the rear SAM control unit and, with model 211.2, to the rear-end door control unit.

On vehicles with code (550) Trailer hitch, the request is additionally detected by the trailer connection unit [AAG] control unit over CAN-B.

Function during wiper startup 

Upon activation of the windshield wiper system for min. 20 s with a wipe cycle period of less than 6 s, the headlamps are switched on.

If there are no wipe cycles for min. 20 s, the headlamps are switched off.

Actuations 

Automatic headlight range adjustment (HRA [LWR]) 

Function requirements 

Function 

The automatic headlamp range adjustment enables the light range of the vehicle headlamps to be corrected as a function of the load or the vehicle's driving dynamics-related pitch motions.

On vehicles without code (489) Airmatic (semi-active air suspension), the data of the front axle level sensor (B22/2) and rear axle level sensor (B22/3) are read in directly by the xenon headlamp control unit on the left front lamp unit.

On vehicles with code (489) Airmatic (semi-active air suspension), the data of the left front level sensor (B22/8), of the right front level sensor (B22/9) and of the rear axle level sensor are read in by the Airmatic with ADS control unit (N51), then evaluated and made available on CAN-C.

The central gateway control unit detects the data and places them on the CAN-D. From there, the data are called up by the xenon headlamp control unit on the left front lamp unit and then forwarded to the xenon headlamp control unit on the right front lamp unit.

The ESP control unit (N47-5) places information on the vehicle speed on CAN-C, from where it is made available to the xenon headlamp control units by the central gateway control unit over CAN-D.

The xenon headlamp control units process all the data and actuate the left headlamp range adjustment motor (E1m1) and the right headlamp range adjustment motor (E2m1) accordingly over LIN.

IMPORTANT Both xenon headlamp control units operate as a master-slave combination, whereby the xenon headlamp control unit on the left front lamp unit assumes the role of the master control unit.

Instrument cluster, component description A1 GF54.30-P-6000TM
Rain/light sensor location/task/function B38/2 GF54.21-P-4123Q
Xenon headlamp control unit, component description E1n1, E2n1 GF82.10-P-2114TM 
Driver-side SAM control unit with fuse and relay module, location/task/design N10/1 GF54.21-P-4109T
Rear SAM control unit with fuse and relay module, location/task N10/2  
Model 211.0 GF54.21-P-4130T
Model 211.2 GF54.21-P-4130TA
Front passenger-side SAM control unit with fuse and relay module, location/task/design N10/11 GF54.21-P-4111T
Trailer recognition control unit, location/task N28/1
With code (550) Trailer hitch
GF82.10-P-2106T 
Overhead control panel control unit, location/task/design N70 GF82.20-P-4110T 
Electronic ignition switch control unit, location/task N73 GF80.57-P-4120T
Steering column module, location/task N80 GF54.21-P-4125T
Rear-end door control unit, location/task N111
Model 211.2
GF68.80-P-4002TA
Rotary light switch module, location/task/design S1 GF82.10-P-4104T