GF82.10-P-2009TMA Headlamp Control, Function
GF82.10-P-2009TMA Headlamp Control, Function
- 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)
Component Identification:
Low beam actuation
Function requirements
^ Circuit 30
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 bixenon lamp.
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
^ for high beam, circuit 15R and low beam On function
^ for headlamp flasher circuit 15R On function
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.
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 activated via instrument cluster
^ Terminal 61 ON
Function
The instrument cluster sends the status of the daytime running lamps function over CAN-B to the following control units:
^ Driver-side SAM control unit
^ Front passenger-side SAM control unit
^ Rear SAM control unit
^ Trailer connection unit [AAG] control unit
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
^ The driver-side SAM control unit actuates the left standing lamp and the left front side-marker lamp (United States Of America) (E6/1) as well as the right front side-marker lamp (United States Of America) (E6/2). At the same time, the request is forwarded directly to the corresponding xenon headlamp control unit, which then actuates the left bi-xenon lamp.
^ The front passenger-side SAM control unit actuates the left standing lamp and forwards the request directly to the corresponding xenon headlamp control unit, which then actuates the right bi-xenon lamp.
^ With model 211.0, the rear SAM control unit actuates the taillamps and the license plate lamps.
^ With model 211.2, the rear SAM control unit actuates the taillamps only.
^ With model 211.2, the rear-end door control unit actuates the license plate lamps.
^ With code (550) Trailer hitch, the trailer connection unit [AAG] control unit actuates the AHV socket accordingly.
Automatic headlamp actuation
Function requirements
^ Rotary light switch in "AUTO" position
^ Rain/light sensor signals darkness
Function as at start of journey:
^ Transmitter key disconnected Exterior lights Off
^ Circuit 15C Exterior lights Off
^ Circuit 15R Standing lamps ON
^ Circuit 15 Standing lamps ON
^ Terminal 61 Standing lamp/low beam On (high beam permissible)
Function as at end of journey:
^ Terminal 61 Standing lamp/low beam On (high beam permissible)
^ Circuit 15 Standing lamp/low beam On (high beam permissible)
^ Circuit 15R Standing lamps ON
^ Circuit 15C Standing lamps ON
^ Transmitter key disconnected Exterior lights Off
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
^ The driver-side SAM control unit actuates the left standing lamp and the front side-marker lamps (United States of America). At the same time, the request is forwarded directly to the corresponding xenon headlamp control unit, which then actuates the left bi-xenon lamp.
^ The front passenger-side SAM control unit actuates the right standing lamp and forwards the request directly to the corresponding xenon headlamp control unit, which then actuates the right bi-xenon lamp.
^ With model 211.0,the rear SAM control unit actuates the taillamps and the license plate lamps.
^ With model 211.2,the rear SAM control unit actuates the taillamps only.
^ With model 211.2,the rear-end door control unit actuates the license plate lamps.
^ With code (550) Trailer hitch, the trailer connection unit [AAG] control unit actuates the AHV socket.
Automatic headlight range adjustment (HRA [LWR])
Function requirements
^ Circuit 15 ON
^ Headlamps On (low beam or high beam)
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.
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.
