GF82.10-P-2009RC Headlamp Control, Function
GF82.10-P-2009RC Headlamp Control, Function
- except CODE (614) Bi-xenon headlamp unit
- except CODE (618) Bi-xenon headlamps
driving lights actuation, general
The driving lights actuation includes all functions which serve the optimum illumination of the road while driving.
The standing lights/parking lights actuation is active during driving lights actuation.
The standing lights/parking lights actuation is described in a separate document.
The driving lights actuation function is comprised of the following subfunctions:
^ Low beam actuation function sequence
^ High beam actuation function sequence
^ Daytime running lights actuation function sequence
^ Auto on/off headlamps function sequence (with code (345) Rain sensor)
^ Headlamp range adjustment function sequence (HRA LWR])
Additional low beams actuation function requirements
^ Rotary light switch (S1) in manual driving lights position
Low beam actuation function sequence
The driver-side SAM control unit with fuse and relay module (N10/1) reads in the status of the rotary light switch directly and actuates the left low beams (E1e2) and the right low beams (E2e2).
Additional high beams actuation function requirements
^ For high beams function: circuit 15R and low beams On
^ For headlamp flasher function: circuit 15R On
High beam actuation function sequence
The high beams actuation is comprised of the following subfunctions:
^ Function sequence for high beams
^ Headlamp flasher function sequence
Function sequence for high beams
The high beams actuation is requested by pressing the combination switch (S4) forward. The switch position of the combination switch is read in by the steering column tube module (N80) and transmitted via the interior CAN to the driver-side SAM control unit. The EIS [EZS] control unit (N73) provides the status of circuit 15 on the interior CAN. The driver-side SAM control unit reads in all of the relevant information, actuates the left high beams (E1e1) as well as the right high beams (E2e1) and transmits the status message "High beams actuation active" via the interior CAN to the instrument cluster (A1). The instrument cluster then actuates the high beam indicator lamp (A1e3).
Headlamp flasher function sequence
The function sequence and the signal flow of the headlamp flasher function are identical to that of the high beams function. To request the headlamp flasher function, the combination switch must be pulled backwards. The high beams actuation remains active for as long as the combination switch is held in this position.
In vehicles with code (494) USA version, the high beams may not be actuated at the same time as the left front fog lamp (E5/1) and the right front fog lamp (E5/2).
The current incoming request has priority.
Additional function requirements, daytime running lights actuation
^ Function activated via the instrument cluster
(only countries without legal daytime running lights specification)
^ Engine running (circuit 61 ON) n > 300 rpm
Daytime running lights actuation function sequence
The request for the daytime running lights function is output depending on the country coding or activated manually by the instrument cluster on the interior CAN.
The circuit status of circuit 61 in vehicles with engine 113 or 271 is defined by the driver-side SAM control unit.
In vehicles with engine 272, the circuit status of circuit 61 is provided by the ME-SFI [ME] control unit (N3/10) on the engine compartment CAN and relayed by the central gateway control unit (N93) to the interior CAN. The driver-side SAM control unit reads in all of the relevant information, evaluates it, and actuates the low beams.
The daytime running lights have a higher priority than the auto on/off headlamps. In countries with legal requirements, only the headlamp flasher is permissible but not the high beams. The high beams are only permissible, when the driving lights are switched on manually via the rotary light switch (in vehicles without code (494) USA version).
Additional function requirements, auto on/off headlamps
^ Engine running (circuit 61 ON) n > 300 rpm
^ Rotary light switch in auto on/off headlamps position
^ Rain/light sensor (B38/2) (with code (345) Rain sensor) signals darkness
Auto on/off headlamps function sequence
Journey commencement:
- Transmitter key (A8/1) removed Exterior lights OFF
- Circuit 15C ON Exterior lights OFF
- Circuit 15R ON standing lights ON
- Circ. 15 ON standing lights ON
- Terminal 61 ON standing lights/low beams ON (high beams permissible)
End of journey:
- Terminal 61 ON standing lights/low beams ON (high beams permissible)
- Circuit 15R ON standing lights ON
- Circuit 15C ON standing lights ON
- Transmitter key disconnected Exterior lights OFF
When the driver door is opened while circuit 15C is On, the standing lights are switched off.
The ambient brightness is recorded by the rain/light sensor. The status of the rain/light sensor is read in by the overhead control panel control unit (N70) and provided on the interior CAN. If darkness is recognized, the driver-side SAM control unit actuates the low beams.
When the windshield wiper system is activated for t ≥20 s with a wipe cycle of t < 6 s, the low beams are switched on. If the wipe cycles remain off for t ≥60 s, the low beams are switched off.
Headlamp range adjustment (HRA [LWR]) function sequence
The headlamp range adjustment is installed as passive safety equipment in vehicles fitted with halogen headlamps to prevent them from dazzling oncoming traffic. The headlamp range adjustment keeps the incline angle of the driving lights within the legally prescribed limits dependent on the position of the headlamp range adjustment selector wheel, which is located on the rotary light switch.
The left headlamp range adjustment motor (E1m1) and the right headlamp range adjustment motor (E2m1) are actuated via the headlamp range adjustment selector wheel.
