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

MODEL 218 

Information on equipment variants 

The following list includes all possible versions of the left front lamp unit (E1) and the right front lamp unit (E2).

To improve the readability of this function description, the following text does not reference the comprehensive equipment codes. Instead, signal words are used that create an association with the equipment cited.

The following variants of the front lamp units are offered, depending on the vehicle equipment:

• Lamp units in xenon version (up to 31.08.2014) 

  (without CODE 621 (Intelligent Light System (left-hand traffic)) and without CODE 622 (Intelligent Light System (right-hand traffic)))

• Lamp units in full LED version (dynamic up to 31.08.2014) 

  (with CODE 621 (Intelligent Light System (left-hand traffic)) or CODE 622 (Intelligent Light System (right-hand traffic)))

• Lamp units in full LED version (static as of 01.09.2014) 

  (with CODE 631 (Full LED headlamp (without ILS), daytime running lamps integrated in headlamp, for left-hand traffic) or CODE 632 (Full LED headlamp (without ILS), daytime running lamps integrated in headlamp, for right-hand traffic))

• Lamp units in full LED version (dynamic as of 01.09.2014) 

  (with CODE 640 (Full LED for U.S.A. incl. ACTIVE MULTIBEAM LED) or CODE 641 (Full LED headlamp incl. ILS and ACTIVE MULTIBEAM LED (USP!) incl. new light design, dynamic LED for left-hand traffic) or CODE 642 (Full LED headlamp incl. ILS and ACTIVE MULTIBEAM LED (USP!) incl. new light design, dynamic LED for right-hand traffic))

Function requirements, general 

• No overvoltage or undervoltage

Driving lights actuation, general 

Driving lights actuation includes all functions which serve the optimum illumination of the road while driving.

Lamp units in xenon version (up to 31.08.2014) 

The light functions of the low beams and high beams are output via xenon bulbs. The control is performed by the left xenon light control unit (E1n1) and the right xenon light control unit (E2n1).

Lamp units in full LED version 

All light functions (low and high beams, cornering and infrared lights (with CODE 610 (Night View Assist)) as well as parking, standing, and turn signal lights) are output via LEDs.

• Lamp units in full LED version (dynamic up to 31.08.2014): 

  The light functions of the low beams and high beams are controlled by the left front actuation module 2 LED exterior lighting (E1n8) and by the right front actuation module 2 LED exterior lighting (E2n8).

  The front SAM control unit with fuse and relay module (N10/1) applies a control voltage to the respective input channel of the front actuation module 2 LED exterior lighting to output the corresponding light function.

• Lamp units in full LED version (static as of 01.09.2014): 

  The light functions of the low beams and high beams are controlled by the front actuation modules 2 LED exterior lighting.

  The front SAM control unit sends the request to output the respective light function via the chassis CAN 2 (CAN E2) to the left headlamp control unit (E1n9) and to the right headlamp control unit (E2n9). The left headlamp control unit sends the request to output the respective light function via the left headlamp LIN (LIN G1) to the left front actuation module 2 LED exterior lighting. The right headlamp control unit sends the request to output the respective light function via the right headlamp LIN (LIN G2) to the right front actuation module 2 LED exterior lighting.

• Lamp units in full LED version (dynamic as of 01.09.2014): 

  The light functions of the low beams and high beams are controlled by the left front lamp unit LED matrix control unit (E1n11) and by the right front lamp unit LED matrix control unit (E2n11).

  The front SAM control unit sends the request to output the respective light function via the chassis CAN 2 to the front lamp unit LED matrix control units.

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

• Function sequence for low beam actuation 
• Function sequence for high beam actuation 
• Function sequence for daytime running lights actuation 
• Function sequence for auto on/off driving lights 
• Function sequence for automatic headlamp range adjustment (HRA [LWR]) 

Additional function requirements for low beams actuation 

• Terminal 15 ON

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 (S1) 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 directly (voltage-coded) and activates the low beams actuation. The front SAM control unit then sends the "Low beams indicator lamp On" request via the interior CAN to the instrument cluster (A1). The instrument cluster then actuates the low beams indicator lamp (A1e67).

Lamp units in xenon version (up to 31.08.2014): 

The front SAM control unit applies a control voltage (circuit 56b) to the respective input channel of the xenon light control unit. The left xenon light control unit actuates the left xenon bulb with integrated ignition module (E1e10). The right xenon light control unit actuates the right xenon bulb with integrated ignition module (E2e10).

Lamp units in full LED version: 

• Lamp units in full LED version (dynamic up to 31.08.2014): 

  The front SAM control unit applies a control voltage (circuit 56b) to the corresponding input channel of the respective front actuation module 2 LED exterior lighting. The left front actuation module 2 LED exterior lighting then actuates the left low beam (short range) (E1e15) and the left low beam (long range) (E1e16). The right front actuation module 2 LED exterior lighting actuates the right low beam (short range) (E2e15) and the right low beam (long range) (E2e16).

• Lamp units in full LED version (static as of 01.09.2014): 

  The front SAM control unit sends the "Low beams On" request via the chassis CAN 2 to the headlamp control units. The left headlamp control unit sends the "Low beams On" request via the left headlamp LIN to the left front actuation module 2 LED exterior lighting. The left front actuation module 2 LED exterior lighting then actuates the left low beam (short range) and the left low beam (long range).

  The right headlamp control unit sends the "Low beams On" request via the right headlamp LIN to the right front actuation module 2 LED exterior lighting. The right front actuation module 2 LED exterior lighting then actuates the right low beam (short range) and the right low beam (long range).

• Lamp units in full LED version (dynamic as of 01.09.2014): 

  The front SAM control unit sends the "Low beams On" request via the chassis CAN 2 to the front lamp unit LED matrix control units. The left front lamp unit LED matrix control unit then actuates the left low beam (short range) and the left low beam (long range). The right front lamp unit LED matrix control unit then actuates the right low beam (short range) and the right low beam (long range).

Additional function requirements for high beam actuation 

• For the manual high beams function: Circuit 15 and low beams on and adaptive high beams function (with CODE 608 (Adaptive Highbeam Assist) or CODE 628 (AUTOMATIC HIGH BEAM CONTROL PLUS (IHC+))) switched off

  When the adaptive high beams function is active, the high beams are automatically switched on if no other road users are detected in front or behind who could be dazzled.

• For headlamp flasher function: Circuit 15R On

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:

• Function sequence for high beams (manual) 
• Function sequence for headlamp flasher 

Function sequence for high beams (manual) 

High beam actuation is requested by pushing the combination switch (S4) forward.

The steering column tube module control unit (N80) reads in the switch position of the combination switch directly and sends this via chassis CAN (CAN E) (up to 28.02.2013) or chassis CAN 1 (CAN E1) (as of 01.03.2013) to the front SAM control unit. The front SAM control unit receives the switch position of the combination switch and uses this to generate the request "High beams On". The front SAM control unit then sends the "High beams On" status via the interior CAN to the instrument cluster. The instrument cluster receives this and actuates the high beams indicator lamp (A1e3).

Lamp units in xenon version (up to 31.08.2014): 

The front SAM control unit applies a control voltage (circuit 56a) to the respective input channel of the xenon light control unit. The left xenon light control unit then actuates the left high beam solenoid (E1l1). The right xenon light control unit actuates the right high beam solenoid (E2l1).

The panels which partially cover up the light cones of the xenon bulbs are folded away, thereby releasing the entire light beam to illuminate the roadway.

Lamp units in full LED version: 

• Lamp units in full LED version (dynamic up to 31.08.2014): 

  The front SAM control unit applies a control voltage (circuit 56a) to the corresponding input channel of the respective front actuation module 2 LED exterior lighting.

  The left front actuation module 2 LED exterior lighting then actuates the left high beam (E1e1). The right front actuation module 2 LED exterior lighting actuates the right high beam (E2e1).

• Lamp units in full LED version (static as of 01.09.2014): 

  The front SAM control unit sends the "High beams On" request via the chassis CAN 2 to the headlamp control units. The headlamp control units send the "High beams On" request via the headlamp LIN to the front actuation modules 2 LED exterior lighting. The left front actuation module 2 LED exterior lighting then actuates the left high beam. The right front actuation module 2 LED exterior lighting actuates the right high beam.

• Lamp units in full LED version (dynamic as of 01.09.2014): 

  The front SAM control unit sends the "High beams On" request via the chassis CAN 2 to the headlamp control units and to the front lamp unit LED matrix control units.

  The left headlamp control unit actuates the left light distribution actuator motor (E1m3). The right headlamp control unit actuates the right light distribution actuator motor (E2m3). The entire light beam of the low beams (long distance) is then released for illuminating the roadway.

  The left front lamp unit LED matrix control unit subsequently actuates the left front adaptive high beam (E1e24). The right front LED matrix lamp unit control unit actuates the right front adaptive high beam (E2e24).

  The adaptive high beams are equipped with 24 LEDs each, which can be actuated independently of each other. The formation and intensity of the light cone can be influenced depending on which LEDs are actuated.

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".

On vehicles with lamp units in xenon version (up to 31.08.2014), the low beam actuation must be activated as no separate high beams are installed to implement the headlamp flashing function.

Additional function requirements for 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" or "Drivetrain ready" signal set or vehicle speed v > 3 km/h
• Exterior lights switch in "Auto" position

The instrument cluster sends the "Daytime running lights ON" request (depending on the national coding or manually activated in the "Settings", "Lights" menu) via the interior CAN to the front SAM control unit.

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 operational" signal over the chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013) to the front SAM control unit.

The instrument cluster sends the vehicle speed via the chassis CAN (up to 28.02.2013) or chassis CAN 2 (as of 01.03.2013) to the front SAM control unit.

The front SAM control unit reads in the status of the exterior lights switch directly.

Function sequence for daytime running lights actuation 

Daytime running lights actuation can be switched on and off manually or is hard-coded, depending on the national version.

• Vehicles up to 31.08.2014: 

  The front SAM control unit evaluates all relevant information and actuates the left daytime running lights headlamp (E1/3) and the right daytime running lights headlamp (E2/3).

• Lamp units in full LED version (static as of 01.09.2014): 

  The front SAM control unit evaluates all relevant information and sends the "Daytime running lights On" request via the chassis CAN 2 to the headlamp control unit.

  The left headlamp control unit actuates the left daytime running light (E1e20) and the left front standing light and parking light (E1e3). The right headlamp control unit actuates the right daytime running light (E2e20) and the right front standing light and parking light (E2e3).

• Lamp units in full LED version (dynamic as of 01.09.2014): 

  The front SAM control unit evaluates all relevant information and sends the "Daytime running lights On" request via the chassis CAN 2 to the headlamp control unit.

  The left headlamp control unit actuates the daytime running light in the left position light, daytime running light, and turn signal light (E1e25) (not Economic Commission for Europe (ECE) vehicles) or the daytime running light in the left position light, daytime running light, turn signal light, and ambient light (E1e26) (ECE vehicles only).

  The right headlamp control unit actuates the daytime running light in the right position light, daytime running light, and turn signal light (E2e25) (not ECE vehicles) or the daytime running light in the right position light, daytime running light, turn signal light, and ambient light (E2e26) (ECE vehicles only).

  If the turn signal is activated during daytime running lights actuation on ECE vehicles, the daytime running lights are dimmed to position light level (approximately 10 percent). The turn signal light and daytime running light are actuated in alternate fashion.

  On vehicles with CODE 460 (Canada version) or CODE 494 (USA version), if the turn signal is activated during daytime running lights actuation, the daytime running lights actuation is suspended and only the turn signal light is actuated.

When it is dark, the daytime running lights actuation is actuated with reduced power (night design circuit) and the low beams actuation is activated.

The ambient brightness is recorded by the rain/light sensor (B38/2). The rain/light sensor sends the "Switch on low beams" request via the wiper/inside rearview mirror LIN (LIN 2) to the front SAM control unit.

In vehicles with CODE 498 (Japan version) or with the Korea national version, the daytime running lights actuation is always activated together with the low beams actuation.

The daytime running lights actuation is deactivated as soon as the exterior lights switch is turned to the standing lights, manual driving lights, left parking light, or right parking light position (except for vehicles with CODE 460 (Canada version)).

In 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 compared to the auto on/off driving lights. 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 are manually switched on via the exterior lights switch (without CODE 460 (Canada version) or without CODE 494 (USA version)).

Additional function requirements for auto on/off driving lights 

• "Engine running" or "Drivetrain ready" signal set or vehicle speed v > 3 km/h
• Exterior lights switch in "Auto" position

The CDI control unit or the ME-SFI [ME] control unit sends the "Engine running" or the "Drivetrain operational" signal over the chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013) to the front SAM control unit.

The instrument cluster sends the vehicle speed via the chassis CAN (up to 28.02.2013) or chassis CAN 2 (as of 01.03.2013) to the front SAM control unit.

The front SAM control unit directly reads in the status of the exterior lights switch (voltage-coded).

Function sequence for auto on/off driving lights 

With the auto on/off driving lights, the low beams are automatically switched on and off.

The auto on/off driving lights are purely a comfort function and do not relieve the driver of the need to follow the operating instructions as prescribed by the road traffic regulations.

Behavior of exterior lights when auto on/off driving lights activated
Start of trip	Standing lamp	Low beam
Circuit 15C OFF	Off	Off
Circuit 15C ON	Off	Off
Circuit 15R ON	On	Off
Terminal 15 ON	On	Off
"Engine running" signal or "Drivetrain operational" signal set or v > 3 km/h	On	On (high beams permissible)
End of trip  At the end of a trip, overlaps may occur between the auto on/off driving lights and the headlamp switch-off delay.	Standing lamp	Low beam
"Engine running" signal or "Drivetrain operational" signal set or v > 3 km/h	On	On (high beams permissible)
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

The low beams are switched on or off depending on the ambient brightness or depending on the activities of the windshield wiper system:

• Function sequence for auto on/off driving lights over rain/light sensor 
• Function sequence for auto on/off driving lights over wiper activities 

Function sequence for auto on/off driving lights over rain/light sensor 

Ambient brightness is assessed by the rain/light sensor. The rain/light sensor sends the "Switch on low beams" request via the wiper/inside rearview mirror LIN to the front SAM control unit. The front SAM control unit evaluates this request and activates the low beams actuation.

Detailed information about low beams actuation is given in the chapter "Low beams actuation".

Function sequence for auto on/off driving lights over wiper activities 

If the low beams are switched on or off due to the activities of the windshield wiper system, one refers to wiper, rain or adverse weather light.

The front SAM control unit controls the windshield wiper system and evaluates the data of the rain/light sensor or the wipe request via the combination switch for this purpose.

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.

In the event of any rain/light sensor failure, the auto on/off driving lights 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 driving lights function remains switched on. If the wiper startup suppression function is canceled, the auto on/off driving lights remain active for an additional t = 60 s.

Detailed information about low beams actuation is given in the chapter "Low beams actuation".

Additional function requirements for automatic headlamp range adjustment 

• "Engine running" or "drive train operational" signal on
• Driving lights On (low beam/high beam)

The CDI control unit or the ME-SFI [ME] control unit sends the "Engine running" or "Drivetrain operational" signal as set via the chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013), front SAM control unit, and front end CAN to the xenon light control units (lamp units in xenon version (up to 31.08.2014)) or to the headlamp control units (lamp units in full LED version).

Function sequence for automatic HRA [LWR] 

The automatic HRA [LWR] permits the correction of the headlamp range of the front lamp units as a function of the load or the vehicle pitch motions induced by the vehicle dynamics.

The current vehicle level is recorded for this.

Vehicles without CODE 488 (Steel/air suspension) and without CODE 489 (AIRMATIC (Air suspension with continuously adjustable damping): 

Up to 31.08.2014: 

The left xenon light control unit (lamp units in xenon version) or the left headlamp control unit (lamp units in full LED version (dynamic)) directly reads in the signals from the left rear level sensor (B22/7) and the left front level sensor (B22/8).

As of 01.09.2014: 

The left headlamp control unit (lamp units in full LED version (static)) directly reads in the signal from the left rear level sensor.

The left headlamp control unit (lamp units in full LED version (dynamic)) directly reads in the signals from the left rear level sensor and the left front level sensor.

Vehicles with CODE 488 (Steel/air suspension) or CODE 489 (AIRMATIC (air suspension with continuous adjustment damping)): 

The AIRMATIC control unit (N51/3) directly reads in the signals from the following sensors:

• Left rear level sensor
• Left front level sensor
• Right front level sensor (B22/9)
• Right rear level sensor (B22/10)

The AIRMATIC control unit then sends these signals for evaluation of the vehicle level via the chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013), front SAM control unit, and front end CAN (up to 28.02.2013) or chassis CAN 2 (as of 01.03.2013) to the left xenon light control unit (lamp units in xenon version (up to 31.08.2014)) or to the left headlamp control unit (lamp units in full LED version).

Zero-point programming is performed at the end of the line to compensate vehicle tolerances. With successful programming, visual feedback occurs through the movement of the headlamp units "center-down-up-center".

If the vehicle is moving at a constant speed, the automatic headlamp range adjustment system operates in "static mode" at a slow adjustment rate.

During vehicle acceleration (speed change and additional signals such as brake pedal and accelerator pedal position), "dynamic mode" (except for lamp units in full LED version (static as of 01.09.2014)) is activated in which the reaction time of the automatic HRA is significantly reduced.

When the vehicle is at a standstill, automatic HRA [LWR] is in "dynamic mode".

Vehicles up to 28.02.2013: 

Information about the wheel speeds as indicators of the vehicle speed is sent by the Electronic Stability Program control unit (N30/4) (without CODE 233 (DISTRONIC PLUS) or without engine 157) or the Premium Electronic Stability Program control unit (N30/7) (with CODE 233 (DISTRONIC PLUS) or with engine 157) via the chassis CAN, front SAM control unit, and front end CAN to the left xenon light control unit (lamp units in xenon version) or to the left headlamp control unit (lamp units in full LED version (dynamic)).

The instrument cluster also sends the vehicle speed via the chassis CAN, front SAM control unit, and front end CAN to the xenon light control units (lamp units in xenon version) or to the headlamp control units (lamp units in full LED version (dynamic)).

Both xenon light control units (lamp units in xenon version) or headlamp control units (lamp units in full LED version (dynamic)) operate in a master-slave combination, whereby the respective left control unit functions as the master and synchronizes the right control unit via the front end CAN.

The left xenon light control unit (lamp units in xenon version) or the left headlamp control unit (lamp units in full LED version (dynamic)) actuates the left headlamp range adjustment actuator motor (E1m1). The right xenon light control unit (lamp units in xenon version) or the right headlamp control unit (lamp units in full LED version (dynamic)) actuates the right headlamp range adjustment actuator motor (E2m1).

Vehicles as of 01.03.2013: 

Information on the wheel speeds as indicators of the vehicle speed is sent by the Electronic Stability Program control unit via the chassis CAN 1, front SAM control unit, and chassis CAN 2 to the following control unit:

• Left xenon light control unit (lamp units in xenon version (up to 31.08.2014))
• Left headlamp control unit (lamp units in full LED version)

The instrument cluster also sends the vehicle speed via the chassis CAN 2 to the following control units:

• Xenon light control units (lamp units in xenon version (up to 31.08.2014))
• Headlamp control units (lamp units in full LED version)

Both xenon light control units (lamp units in xenon version (up to 31.08.2014)) or headlamp control units (lamp units in full LED version) operate in a master-slave combination, whereby the respective left control unit functions as the master and synchronizes the right control unit via the chassis CAN 2.

The left xenon light control unit (lamp units in xenon version (up to 31.08.2014)) or the left headlamp control unit (lamps units in full LED version) actuates the left headlamp range adjustment actuator motor. The right xenon light control unit (lamp units in xenon version (up to 31.08.2014)) or the right headlamp control unit (lamp units in full LED version) actuates the right headlamp range adjustment actuator motor.

Electrical function schematic for driving lights actuation	MODEL 218 up to model year 2015 without CODE 621 (Intelligent Light System (left-hand traffic)) without CODE 622 (Intelligent Light System (right-hand traffic))	PE82.10-P-2059-97XAA
Electrical function schematic for driving lights actuation	MODEL 218 up to model year 2015 with CODE 621 (Intelligent Light System (left-hand traffic)) MODEL 218 up to model year 2015 with CODE 622 (Intelligent Light System (right-hand traffic))	PE82.10-P-2059-97XAB
Electrical function schematic for driving lights actuation	MODEL 218 as of model year 2015	PE82.10-P-2059-97XAC
Overview of exterior lights system components		GF82.10-P-9998FQ