GF82.10-P-2009GMB Headlamp Control, Function
GF82.10-P-2009GMB Headlamp Control, Function
- with CODE (615) Bi-xenon headlamp unit with integrated curve illumination
- with CODE (616) Bi-xenon headlamp unit with integrated asymmetrical curve
- with CODE (621) Intelligent Light System (left-hand traffic)
- with CODE (622) Intelligent Light System (right-hand traffic)
Function requirements, driving lights actuation, general
^ No overvoltage or undervoltage (operating voltage range U ≥7 ≤17.5 V)
driving lights actuation, general
driving lights actuation includes all functions which serve the optimum illumination of the road while driving.
During driving light actuation, the standing/parking lights actuation is active, this 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
^ Headlamp range adjustment function sequence (HRA [LWR])
Additional low beams actuation function requirements
^ Circuit 15 On
Low beam actuation function sequence
Turning the rotary light switch (S1) to the "manual driving lights" switch request actuation of the low beams.
The status of circuit 15 is provided by the EIS [EZS] control unit (N73) on the interior CAN (CAN B).
The upper control panel control unit (N72/1) reads in the status of the rotary light switch via the instrument panel LIN (LIN 1) and transmits it via the interior CAN to the front SAM control unit (N10). The front SAM control unit sends the "Switch low beams on" request by transmitting a voltage signal directly to the xenon headlamp control unit (E1n1) at the left front lamp unit (E1) and the xenon headlamp control unit (E2n1) at the right front lamp unit (E2). The xenon headlamp control unit at the left front lamp unit then actuates the left bi-xenon light with integrated ignition module (E1e10).
The xenon headlamp control unit at the right front lamp unit then actuates the right bi-xenon light with integrated ignition module (E2e10).
Additional function requirements, high beam actuation
^ For high beams function: circuit 15 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 made available on the engine compartment CAN (CAN-C).
The central gateway control unit (N93) forwards this via the interior CAN to the front SAM control unit.
The front SAM control unit receives all of the relevant information and actuates the left high beam (E1e1) and the right high beam (E2e1), and in vehicles with code (615) Bi-xenon headlamp unit with integral curve illumination or code (616) Bi-xenon headlamp unit with integral asymmetrical curve illumination, the left high beam solenoid (E1l1) and the right high beam solenoid (E2l1).
With model 164.8 as of 1.7.09 with code (621) Intelligent Light System (left-hand traffic) or code (622) Intelligent Light System (right-hand traffic) the central gateway control unit relays all of the relevant information via the engine compartment CAN to the xenon headlamp control units.
The xenon headlamp control unit at the left front lamp unit actuates the left light distribution cylinder motor (E1m3) and the xenon headlamp control unit at the right front lamp unit actuates the right light distribution cylinder motor (E2m3) via the relevant headlamp-internal local interconnect network (LIN).
The panels which partially cover up the bi-xenon light cone, are folded away thereby releasing the entire light beam to illuminate the traffic lane.
The front SAM control unit then sends the "High beam actuation active" status via the interior CAN to the instrument cluster (A1). This then actuates the high beam indicator lamp (A1e3).
Headlamp flasher function sequence
The function sequence and signal path for the headlamp flasher function correspond to that of the high beam function.
However, to request the headlamp flasher, the combination switch must be pulled backward.
The high beams actuation remains active for as long as the combination switch is held in this position. In vehicles with code (615) Bi-xenon headlamp unit with integral curve illumination or code (616) Bi-xenon headlamp unit with integral asymmetrical curve illumination, if low beam actuation is not active only the high beams are actuated, since it would take too long to ignite the bi- xenon lights and ramp up to full brightness.
In vehicles with Code (460) Canada version or code (494) USA version the high beams must not be actuated at the same time as the left front fog lamp (E5/1) (with model 164.1, model 164.8 up to 30.6.09) and the right front fog lamp (E5/2) (with model 164.1, model 164.8 up to 30.6.09).
The current incoming request has priority.
Additional function requirements, daytime running lights actuation
^ Engine running (circuit 61 On) n > 300 rpm or vehicle speed v > 3 km/h
^ Function activated via the instrument cluster (only countries without legal daytime running lights specification)
^ Rotary light switch in position:
- Exterior lights OFF "0"
- Auto on/off headlamps "AUTO"
- "Left parking light" or "Right parking light" (can be coded)
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 is provided on the engine compartment CAN by the CDI control unit (N3/9) (with diesel engine) or by the ME-SFI [ME] control unit (N3/10) (with gasoline engine) and forwarded by the central gateway control unit via the interior CAN to the front SAM control unit.
Information about the vehicle speed is made available by the instrument cluster on the interior CAN.
Model 164.1, model 164.8 up to 30.6.09:
The front SAM control unit reads in all of the relevant information, evaluates it and outputs the request "Switch on low beams" via a voltage signal directly to the xenon headlamp control units. The xenon headlamp control units then actuate the bi-xenon lamps.
In vehicles with code (460) Canada version or code (494) USA version, low beam actuation is activated in accordance with the ambient brightness. This is detected by the rain/light sensor (B38/2). The information from the rain/light sensor is read in by the overhead control panel control unit (N70) and transmitted via the interior CAN to the front SAM control unit. If it is dark, the front SAM control unit activates both low beam actuation and standing lights actuation. Only low beam actuation takes place during daylight.
Model 164.8 as of 1.7.09 without code (498) Japan version: The front SAM control unit reads in all of the relevant information and actuates the left daytime running lights headlamp (E1/3) or the right daytime running lights headlamp (E2/3).
When it is dark and the rotary light switch is in the "AUTO" position, the front SAM control unit actuates the daytime running lights headlamp at reduced power and activates the low beam actuation.
In vehicles with code (460) Canada version or with code (494) USA version, the low beams are always activated as well.
Daytime running lights actuation is deactivated as soon as the rotary light switch is moved to the "Standing lights" position or the "Manual driving lights" position.
In vehicles with code (460) Canada version or code (494) USA version, daytime running lights actuation is switched off when the vehicle is stationary after a time interval of t = 3 min. When the vehicle then starts to move again, the front SAM control unit automatically activates daytime running lights actuation.
The daytime running lights have a higher priority than the auto on/off headlamps.
In countries with legal daytime running light requirements, only the headlamp flasher is permissible but not the high beams. The high beams are only permissible if the driving lights have been switched on manually via the rotary light switch (without code (460) Canada version or without code (494) USA version).
Additional function requirements, auto on/off headlamps
^ Engine running (circuit 61 On) n > 300 rpm or vehicle speed v > 3 km/h
^ Rotary light switch in position "AUTO" or "0" (can be coded)
^ Rain/light sensor signals "Darkness detected"
Auto on/off headlamps function sequence
The auto on/off headlamps function is no more than a convenience system and does not exempt the driver from following the operating instructions in the road traffic regulations. With auto on/off headlamps, low beam actuation is switched on or off depending on the ambient brightness. The auto on/off headlamps function can be switched on or off via the rain/light sensor or the activities of the wiper system.
Journey commencement:
- Transmitter key Standing lights/low beams OFF
(A8/1) removed
- Circuit 15C ON Standing lights/low beams OFF
- Circuit 15R ON Standing lights ON
- Circuit 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 Standing lights/low beams OFF
disconnected
The standing lights are switched off, as soon as the driver door is opened with the transmitter key (circuit 15C) inserted.
The circuit status of circuit 61 is provided on the engine compartment CAN by the CDI control unit or by the ME-SFI [ME] control unit and forwarded by the central gateway control unit via the interior CAN to the front SAM control unit.
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 and transmitted via the interior CAN to the front SAM control unit.
If darkness is recognized, the front SAM control unit forwards the "Switch on low beams" request by means of a voltage signal straight to the xenon headlamp control units, which then actuate the bi-xenon lights.
If the windshield wiper system is activated for t = ≥20 s with a wipe cycle time of t < 6 s, the front SAM control unit activates low beam actuation. If there are no wipe cycles for ≥20 s, low beam actuation is deactivated.
Auto on/off headlamps switch-off conditions:
In the event of rain/light sensor failure, the auto on/off headlamps are not deactivated until the engine is switched off. When the vehicle is being driven through a tunnel and if the wiper start suppression function is active, the auto on/off headlamps function remains active. If the wiper start suppression function is canceled, the auto on/off headlamps function remains active for an additional t = 20 s.
Additional function requirements, automatic HRA [LWR]
^ Engine running (circuit 61 ON) n > 300 rpm
^ Driving lights On (low beam/high beam)
Function sequence for automatic HRA [LWR]
The automatic HRA [LWR] permits the correction of the headlamp range of the vehicle headlamps as a function of the load or the vehicle pitch motions induced by the vehicle dynamics.
The following information that describes the driving status is included into the computation of the correction values:
- Body pitch angle from the axis positions
- Vehicle speed in order to calculate the operating mode
In vehicles without code (489) AIRmatic (air suspension with level adjustment and adaptive damping system ADS), the xenon headlamp control unit at the left front lamp unit reads in the signals of the right front level sensor (B22/9) and the right rear level sensor (B22/10) and uses them to calculate the vehicle level.
The xenon headlamp control unit at the left front lamp unit transmits corresponding correction values via the engine compartment CAN to the xenon headlamp control unit at the right front lamp unit.
In vehicles with code (489) AIRmatic (air suspension with level adjustment and adaptive damping system ADS), the information about the vehicle level is provided by the AIRMATIC control unit (N51) on the engine compartment CAN.
Information on wheel speeds and wheel rotation directions as an indicator for the vehicle speed is provided by the ESP control unit (N47-5) on the engine compartment CAN.
This information is required to regulate the adjustment rate of the automatic headlamp range adjustment.
If the vehicle is moving at a constant speed, the automatic headlamp range adjustment system operates in "static mode" at a slow adjustment rate.
In the event of acceleration, the "dynamic mode" is activated with a high adjustment rate.
The xenon headlamp control unit at the left front lamp unit reads in all of the relevant information, evaluates it, and as master synchronizes the xenon headlamp control unit at the right front lamp unit.
The xenon headlamp control unit on the left front lamp unit correspondingly actuates the left headlamp range adjustment motor (E1m1), and the xenon headlamp control unit on the right front lamp unit actuates the right headlamp range adjustment motor (E2m1).
With model 164.8 as of 1.7.09 with code (621) Intelligent Light System (left-hand traffic) or code (622) Intelligent Light System (right-hand traffic) the headlamp range adjustment motors are actuated via the respective headlamp-internal local interconnect network (LIN).
