GF82.10-P-2009CWA Headlamp Control, Function
GF82.10-P-2009CWA Headlamp Control, Function
- with CODE (614) Bi-xenon headlamp unit
- with CODE (622) Intelligent Light System (right-hand traffic)
General driving light actuation function sequence
The driving light actuation consists of several subfunctions. These are:
^ Low beam actuation
^ High-beams actuation
^ Daytime running lamps actuation
^ Automatic driving lights on
^ Automatic headlamp range adjustment
^ Turning lamps
Low beam actuation
Function requirements
^ Circuit 30
^ Exterior lights switch (S1) to manual driving lights position (third notch to right)
Low beam actuation function sequence
The position of the exterior lights switch is read in via the instrument panel LIN by the front SAM control unit with fuse and relay module (N10/1).
The front SAM control unit forwards the request via the front end CAN to the left xenon light control unit (E1n1) and the right xenon light control unit (E2n1).
The left xenon light control unit then actuates the left xenon bulb with integral ignition module (E1e10) and the right xenon light control unit actuates the right xenon bulb with integral ignition module (E2e10).
When the low beam is switched on, the light cone is partially covered by the cover that is actuated by the left high beam solenoid (E1l1) and the right high beam solenoid (E2l1).
High-beams actuation
Function requirements
^ for high beam function, circuit 15R and low beam On
^ for headlamp flasher function, circuit 15R On
High beam actuation function sequence
High beam actuation is requested by pushing the combination switch (S4) forward.
The steering column tube module control unit (N80) detects the position of the combination switch and transmits the request to the front SAM control unit via the chassis CAN.
The front SAM control unit receives the request and forwards it to the left xenon light control unit and the right xenon light control unit via the front end CAN.
The left xenon light control unit actuates the left high beam solenoid and the right xenon light control unit actuates the right high beam solenoid, which causes the covers that are partially covering the xenon lamp light cones to be swiveled away.
The left high beam (E1e1) and the right high beam (E2e1) are also directly actuated by the SAM control unit.
Headlamp flasher function sequence
The combination switch must be pulled backwards to activate the headlamp flasher. The high beam is actuated for as long as the combination switch is held in position.
The function sequence and signal path for the headlamp flasher function is the same as for the high beam function.
Feedback
Active high beam/headlamp flasher actuation is transmitted to the instrument cluster (A1) by the front SAM control unit via the interior CAN.
This then actuates the high beam indicator lamp (A1e3).
With the low beam function switched off, only the high beam is switched on when the headlamp flasher is switched on, since the xenon bulbs with integral ignition module would take too long to ignite.
Daytime running lamps actuation
Function requirements
^ Function activated via the instrument cluster (country specific)
^ Circuit 61 ON
Daytime running lights actuation function sequence
The daytime running lamps function is activated by the front SAM control unit. The front SAM control unit then actuates the xenon bulbs via the xenon light control units.
In countries with statutory daytime running lamp regulations, only the headlamp flasher is permitted in daytime running lamp mode, but not the high beam.
Automatic headlamp actuation
Function requirements
^ Exterior lights switch in "Auto" position
^ Light sensor (B38/1) (without code (345) Rain sensor) or rain/light sensor (B38/2) (with code (345) Rain sensor) signaling darkness
Auto on/off headlamps function sequence
Function at start of journey (in darkness)
The standing lights are activated as of circuit 15R On. The low beams are also activated with circuit 61 On. It is possible then to switch on the high beams.
Function at end of journey (in darkness)
The low beams (high beams, if necessary) are deactivated when the engine is switched off. The standing lights are not switched off until the transmitter key (A8/1) is removed from the electronic ignition lock control unit (N73).
Function while driving
The light sensor or the rain/light sensor detects the ambient brightness. When darkness is detected, the relevant request is forwarded to the front SAM control unit via the wiper/inside rearview mirror LIN.
Function at wiper startup:
When the wiper system is actuated for t = 20 s with a wipe cycle period of t < 6 s, the front SAM control unit actuates the left and right low beams.
If there is no wipe cycle for t = 60 s, the driving lights are switched off.
Automatic headlamp range adjustment
Function requirements
^ Circ. 15 ON
^ Driving lights On (low beam/high beam)
Automatic headlight range adjustment function sequence
The automatic headlamp range adjustment serves to correct the headlamp range of the vehicle headlamps as a function of the load or the vehicle pitch motions induced by the vehicle dynamics. In vehicles (without code (483) ADVANCED AGILITY package) the left xenon light control unit reads in the left rear level sensor (B22/7) and the left front level sensor (B22/8).
In vehicles (with CODE (483) ADVANCED AGILITY package) the level sensor data is sent to the chassis CAN by the adaptive damping system control unit (N51/5), received by the front SAM control unit and transmitted to the left xenon light control unit via the front end CAN.
Both xenon light control units operate in a master/slave combination, whereby the left xenon light control unit acts as the master control unit.
The left xenon light control unit processes all of the information and forwards appropriate correction data to the right xenon light control unit.
The left xenon light control unit actuates the left headlamp range adjustment actuator motor (E1m1) and the right xenon light control unit actuates the right headlamp range adjustment actuator motor (E2m1).
Cornering illumination
Function requirements
^ Engine running (circuit 61 ON)
^ Low beam on and light sensor or rain/light sensor signaling darkness
^ Turn signaling active and speed v < 40 km/h (not United States or America) or v < 60 km/h (with United States Of America) or steering angle detected and speed v < 70 km/h
Cornering illumination function sequence
The cornering illumination function makes it possible to provide better road illumination in the cornering direction, and is implemented using the left front fog lamp (E5/1) and the right front fog lamp (E5/2).
Only one front fog lamp is actuated, the inside corner lamp during forward travel and the outside corner lamp when reversing. It is always switched on and off with dimming.
The front SAM control unit is responsible for evaluating all relevant information and the resulting actuation.
The cornering direction is defined by the turn signaling function or the steering angle, as detected by the steering angle sensor (N49), and is transmitted to the front SAM control unit by the steering column tube module control unit via the chassis CAN. The front SAM control unit receives the request and actuates the relevant front fog lamp. If the request is suddenly canceled, the cornering illumination function remains active for a minimum switch-on time of approx. t = 5 s.
At a speed of v < 40 km/h, the turn signaling request has priority over the steering angle request.
