GF82.10-P-2009CAA Headlamp Control, Function
GF82.10-P-2009CAA 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 illumination
- 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 lights actuation, the standing lights actuation is active; this is described in a separate document.
The driving lights actuation comprises 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
^ Function sequence for automatic headlamp range adjustment (HRA [LWR])
The driving lights are actuated corresponding to the position of the exterior lights switch (S1). The status of the exterior lights switch is read by the front SAM control unit with fuse and relay module (N10/1) in model 207.3 up to 31.5.10 via instrument panel LIN (LIN 1) and in model 207.3 as of 1.6.10, model 207.4 (voltage coded) directly.
Additional low beams actuation function requirements
^ Circuit 15 ON
Low beam actuation function sequence
Turning the exterior lights switch to the "Manual driving lights" position requests actuation of the low beams.
The electronic ignition lock control unit (N73) transmits the circuit status of circuit 15 to the front SAM control unit via the interior CAN (CAN B).
The front SAM control unit reads in the status of the exterior lights switch and directly outputs the request via a voltage signal to the left xenon light control unit (E1n1) and to the right xenon light control unit (E2n1).
It additionally transmits the request "Low beams indicator lamp On" via interior CAN to the instrument cluster (A1), which then actuates the low beams indicator lamp (A1e67).
The left xenon light control unit 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).
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
High beam actuation is requested by pushing the combination switch (S4) forward.
The steering column tube module control unit (N80) directly reads in the position of the combination switch and transmits it to the front SAM control unit via the chassis CAN (CAN E).
The front SAM control unit receives the switch position of the combination switch, uses it to generate the request "High beams On", and transmits it via interior CAN to the instrument cluster and via front end CAN (CAN G) to the xenon light control units. The instrument cluster then actuates the high beam indicator lamp (A1e3). The left xenon light control unit actuates the left light distribution actuator motor (E1m3) and the right xenon light control unit actuates the right light distribution actuator motor (E2m3) via the relevant headlamp-internal Local Interconnect Network (LIN). The rollers which partially cover up the xenon bulb's light cone, are turned away thereby releasing the entire light beam to illuminate the traffic lane.
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 function, the combination switch must be pulled backward. However, if the combination switch is pulled back permanently, the high beams actuation remains active for a maximum of t = 30 s. The permanently present request is then interpreted as a "stuck combination switch".
Since no separate high beams are installed to implement the headlamp flasher function, the xenon bulbs must be illuminated when low beams actuation is not active.
In vehicles with code (460) Canada version or code (494) USA version, the high beams function must not be used if left front fog lamp (E5/1) and right front fog lamp (E5/2) actuation is active. The currently present request has priority.
Additional function requirements, daytime running lights actuation
^ "Daytime running lights:" function activated in "Settings", "Light" menu in instrument cluster (except vehicles with code (460) Canada version)
Engine running (n > 300 rpm) or circuit 61 On or vehicle speed v > 3 km/h
Exterior lights switch in position:
- Exterior lights Off "0" or
- "Left parking lights" or "Right parking lights" (model 207.3 up to 31.5.10) (can be coded) or
- Auto on/off headlamps "AUTO"
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.
Status of circuit 61 and the engine speed are transmitted by the CDI control unit (N3/9) (with diesel engine) or the ME-SFI [ME] control unit (N3/10) (with gasoline engine) via chassis CAN.
The instrument cluster transmits the vehicle speed via interior CAN.
The front SAM control unit reads in all relevant information, evaluates it and actuates the left daytime running light (E1/3) and right daytime running light (E2/3) on vehicles without code (498) Japan version.
On vehicles with code (498) Japan version, the daytime running light function is output by the low beam actuation, because daytime running lights are not installed.
When dark, the front SAM control unit actuates the daytime running light headlamps with reduced power and also activates the low beam actuation.
The ambient brightness is recorded by the rain/light sensor (B38/2). The front SAM control unit reads in the data of the rain/ light sensor via wiper/inside rearview mirror LIN (LIN 2).
The daytime running lights actuation is deactivated as soon as the exterior lights switch is turned to position "Standing lights", "Manual driving lights" or "Left parking light" or "Right parking light" (model 207.3 as of 1.6.10, model 207.4).
On vehicles with code (460) Canada version, the daytime running light actuation is switched off after expiration of a time interval of t = 3 min when the vehicle is standing still.
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 permissible only when the high beams are manually switched on via the exterior lights switch (without code (460) Canada version and without code (494) USA version).
Additional function requirements, auto on/off headlamps
^ Engine running (n > 300 rpm) or circuit 61 On or vehicle speed v > 3 km/h
^ Exterior lights switch in position "AUTO" or "0" (model 207.3 up to 31.5.10) (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 automatic on/off headlamps can be switched on or off via the light sensor or rain/light sensor as well as by activating 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
- Engine is running or standing lights/low beams ON
Circuit 61 On or (high beams permissible)
v > 3 km/h
End of journey:
- Engine is running or standing lights/low beams ON
Circuit 61 On or (high beams permissible)
v > 3 km/h
- 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 CDI control unit or the ME-SFI [ME] control unit transmits the circuit 61 status and the engine speed via chassis CAN. The instrument cluster transmits the vehicle speed via interior CAN.
The ambient brightness is recorded by the rain/light sensor. The front SAM control unit reads in the data of the rain/light sensor via wiper/inside rearview mirror LIN.
If darkness is recognized the front SAM control unit actuates the low beams.
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 t ≥60 s, low beam actuation is deactivated.
Additional automatic headlamp range adjustment function requirements
^ Engine is running (n > 300 rpm) or circuit 61 On
^ 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 circuit status of circuit 61 is provided by the CDI control unit or the ME-SFI [ME] control unit on the chassis CAN.
In order to determine the current vehicle level in vehicles without code (483) ADVANCED AGILITY package, the voltage signals of the left rear level sensor (B22/7) and left front level sensor (B22/8) are read in directly by the left xenon light control unit.
On vehicles with code (483) ADVANCED AGILITY package, the voltage signals of the following sensors are recorded by the adaptive damping system control unit (N51/5) and provided on the chassis CAN:
- Left rear level sensor
- Left front level sensor
- Right front level sensor (B22/9)
- Right rear level sensor (B22/10)
Zero point programming is performed at the end of the line to compensate vehicle tolerances.
Successful programming is confirmed by visual feedback by the motion sequence of the headlamps "Middle down, Up middle".
If the vehicle is moving at a constant speed, the automatic headlamp range adjustment system operates in "static mode" at a slow adjustment rate.
When the vehicle is accelerated, the "dynamic mode" is activated by highly reducing the reaction time of the system. The "dynamic mode" is activated depending on the speed change and additional signals from the brake pedal and the accelerator pedal positions.
When the vehicle is standing automatic headlamp range adjustment is accomplished in the "dynamic mode".
Information on wheel speed and wheel rotation direction, as an indicator for the vehicle speed, are provided by the Electronic Stability Program control unit (N30/4) (without code (233) DISTRONIC PLUS) or by the Electronic Stability Program Premium control unit (N30/7) (with code (233) DISTRONIC PLUS) on the chassis CAN and forwarded by the front SAM control unit via front end CAN to the xenon light control units.
Both xenon light control units receive this information and communicate with each other via front end CAN.
The xenon light control units operate in a master/slave combination, whereby the left xenon light control unit acts as the master and synchronizes 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) accordingly; in each case, this is done via the Local Interconnect Network (LIN) (headlamp-internal).
