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Headlamp control, function - GF82.10-P-2009FL

MODEL 212.0 /228.2.13 

except CODE (615) Bi-xenon headlamp unit with integrated curve illumination 

except CODE (616) Bi-xenon headlamp unit with integrated asymmetric curve illumination 

except CODE (621) Intelligent Light System (left-hand traffic) 

except CODE (622) Intelligent Light System (right-hand traffic) 

Function requirements, general 

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 the "Standing/parking lights actuation, function" document.

The driving lights actuation function is comprised of the following subfunctions:

IMPORTANT The driving lights are actuated corresponding to the position of the exterior lights switch (S1). The front SAM control unit with fuse and relay module (N10/1) directly reads in the status of the exterior lights switch for model 212.0 up to 30.11.09 except model 212.077 over the instrument panel LIN (LIN 1) and for model 212.077, 212.2 and model 212.0 as of 1.12.09.

Additional low beams actuation function requirements 

IMPORTANT The electronic ignition lock control unit (N73) sends the status of circuit 15 to the front SAM control unit over the interior CAN (CAN B).

Function sequence for low beam actuation 

Turning the exterior lights switch to the "Manual driving lights" position requests actuation of the low beams. The front SAM control unit reads in the status of the exterior lights switch and actuates the left low beam (E1e2) in the left front lamp unit (E1) and the right low beam (E2e2) in the right front lamp unit (E2). In addition, the front SAM control unit sends the request "Low beams indicator lamp On" via interior CAN to the instrument cluster (A1), which then actuates the low beams indicator lamp (A1e67).

Additional function requirements for high beam actuation 

IMPORTANT The electronic ignition lock control unit sends the status of circuit 15 to the front SAM control unit over the interior CAN.

Function sequence for high beam actuation 

The high beams actuation is comprised of the following subfunctions:

D Function sequence for high beams 

D Function sequence for headlamp flasher 

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", transmits it via interior CAN to the instrument cluster and actuates the left high beams (E1e1) and the right high beams (E2e1). The nstrument cluster actuates the high beams indicator lamp (A1e3).

Function sequence for headlamp flasher 

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. If the combination switch is pulled back and held, the high beam actuation is active for maximum t = 30 s. The permanently present request is then interpreted as a "stuck combination switch".

IMPORTANT In vehicles with code (460) Canada version or 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 last incoming request has priority.

Additional function requirements for daytime running lights actuation 

Daytime running lights actuation function sequence 

The instrument cluster sends the request "Daytime running lights On" depending on the country coding or if the daytime running lights request was manually activated in the menu "Settings", "Light" via interior CAN.

The CDI control unit (N3/9) (with diesel engine) or the ME-SFI [ME] control unit (N3/10) (with gasoline engine) sends the "engine running" or "drivetrain ready" signal over the chassis CAN. The instrument cluster sends the vehicle speed over the interior CAN. The front SAM control unit reads in all of the relevant information, evaluates this and actuates the left daytime running lights headlamp (E1/3) and the right daytime running lights headlamp (E2/3).

In darkness the front SAM control unit also actuates the low beams. The ambient brightness is sensed 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 212.077, 212.2 and model 212.0 as of 1.12.09).

In vehicles with code (460) Canada version, the front SAM control unit terminates the daytime running lights actuation when the vehicle is at a standstill once a period of t = 3 minutes has expired. If the vehicle is moved again, the front SAM control unit automatically activates the daytime running lights actuation.

IMPORTANT The daytime running lights have a higher priority compared to 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 for auto on/off headlamps

Function sequence for auto on/off headlamps 

The auto on/off headlamps function is no more than a comfort function and does not exempt the driver from following the rules in the road traffic regulations.

The CDI control unit or the ME-SFI [ME] control unit sends the "engine running" signal or the "drivetrain operational" signal over the chassis CAN to the front SAM control unit.

The instrument cluster sends the vehicle speed to the front SAM control unit over the interior CAN. The front SAM control unit reads in the status of the exterior lights switch over the instrument panel LIN or directly and the rain/light sensor data over the wiper/inside rearview mirror LIN.

With the auto on/off headlamps, the low beams are automatically switched on or off. This occurs depending on the ambient brightness or depending on the activities of the wiper system:

Function sequence for auto on/off headlamps over rain/light sensor 

Ambient brightness is assessed 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 and activates the low beams actuation if darkness is recognized.

Function sequence for auto on/off headlamps via wiper activities 

If the low beams are switched on or off due to the activities of the wiper system, one refers to wiper, rain or adverse weather light. The front SAM control unit controls the wiper system and evaluates the data of the rain/light sensor or the wipe request via the combination switch for this.

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 beams actuation is deactivated.

IMPORTANT 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 switched on. If the wiper startup suppression function is canceled, the auto on/off headlamps remain active for an additional t = 60 s.

Behavior of exterior lights with active auto on/off headlamps:     
Start of trip  Side lamp  Dipped beam 
Circuit 15C OFF Off Off
Circuit 15C ON Off Off
Circuit 15R ON On Off
Circuit 15 ON On Off
"Engine running" signal or "Drivetrain ready" signal set or v > 3 km/h On On (high beams permissible)
End of trip  Side lamp  Dipped beam 
"Engine running" signal or "Drivetrain ready" signal set or v > 3 km/h On On (high beams permissible)
Circuit 15 ON On Off
Circuit 15R ON On Off
Circuit 15C ON (driver door closed) On Off
Circuit 15C ON (driver door open) Off Off
Circuit 15C OFF Off Off

Additional function requirements for automatic headlamp range adjustment 

Function sequence for headlamp range adjustment (HRA [LWR]) 

The headlamp range adjustment is installed as passive safety equipment in vehicles fitted with halogen headlamps to prevent them from causing glare to oncoming traffic. Depending on the load condition of the vehicle, the incline angle of the driving lights can be corrected by operating the headlamp range controller (S1s8) on the exterior lights switch.

The left headlamp range adjustment actuator motor (E1m1) and the right headlamp range adjustment actuator motor (E2m1) are actuated voltage-coded in accordance with the position of the headlamp range adjuster. These then adjust the headlamp units in the front lamp units.

REFER TO SYSTEM WIRING DIAGRAMS Electrical function schematic for driving lights actuation   PE82.10-P-2059-97DAA
  Overview of exterior lights system components   GF82.10-P-9998FL 
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