LEMON Manuals: Even more car manuals for everyone
Home >> Mercedes Benz >> 2021 >> C300 Base, 2D Convertible >> Repair and Diagnosis >> Accessories & Equipment >> Interior/Illumination Lights >> Electrical System - Body - 205 Chassis 1 Of 6 >> Basic Knowledge >> Headlamp Control, Function >> Headlamp Control, Function - GF82.10-P-2009RFM

Headlamp Control, Function - GF82.10-P-2009RFM

Model 205 

as of model year 2019 

with code 631 (Static LED headlamps, left-hand traffic) 

Model 205 

as of model year 2019 

with code 632 (Headlamps, LED, static, right-side traffic) 

Model 205 

as of model year 2019 

with code 640 (High-performance LED) 

Model 205 

as of model year 2019 

with code 641 (Dynamic LED headlamps, left-hand traffic) 

Model 205 

as of model year 2019 

with code 642 (Dynamic LED headlamps, right-hand traffic) 

Model 253 (except 253.99) 

as of model year 2020 

with code 631 (Static LED headlamps, left-hand traffic) 

Model 253 (except 253.99) 

as of model year 2020 

with code 632 (Headlamps, LED, static, right-side traffic) 

Model 253 (except 253.99) 

as of model year 2020 

with code 640 (High-performance LED) 

Model 253 (except 253.99) 

as of model year 2020 

with code 641 (Dynamic LED headlamps, left-hand traffic) 

Model 253 (except 253.99) 

as of model year 2020 

with code 642 (Dynamic LED headlamps, right-hand traffic) 

Model 253.99 

with code 631 (Static LED headlamps, left-hand traffic) 

Model 253.99 

with code 632 (Headlamps, LED, static, right-side traffic) 

Function requirements, general 

Driving lights actuation, general 

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

The driving lights actuation encompasses the following subfunctions:

IMPORTANT The driving lights are actuated corresponding to the position of the exterior lights switch (S1). The front SAM control unit (N10/6) reads in the status of the exterior lights switch directly.

Additional function requirements for low beams actuation 

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).

IMPORTANT The standing lights are active during low beams actuation.

Function sequence for low beam actuation 

Turning the exterior lights switch into the "low beams" position requests actuation of the low beams.

The front SAM control unit reads in the status of the exterior lights switch directly, evaluates this and transmits the "Low beams indicator lamp ON" request via the interior CAN, the electronic ignition lock control unit and the user interface CAN (CAN HMI) to the instrument cluster (A1), which then actuates the low beams indicator lamp.

IMPORTANT The active exterior lights function is displayed via an appropriate indicator lamp in the instrument cluster.

If the standing lights are active, for example, the instrument cluster actuates the standing lights indicator lamp. If low beams actuation is now activated, the instrument cluster switches the standing lights indicator lamp off and actuates the low beams indicator lamp.

Vehicles with CODE 631 (Static left-hand traffic LED headlamp) or CODE 632 (Static right-hand traffic LED headlamp) 

The front SAM control unit sends the request "Low beams on" via interior CAN, electronic ignition lock control unit and peripherals CAN (CAN PER) to the left headlamp control unit (E1n9) on the left front lamp unit (E1) and to the right headlamp control unit (E2n9) on the right front lamp unit (E2).

The left headlamp control unit directly actuates the left low beam (E1e2). The right headlamp control unit directly actuates the right low beam (E2e2).

Vehicles with CODE 640 (High Performance LED) or CODE 641 (DYNAMIC LEFT-HAND TRAFFIC LED HEADLAMP) or CODE 642 (DYNAMIC RIGHT-HAND TRAFFIC LED HEADLAMP) 

The front SAM control unit transmits the "low beams ON" request via the interior CAN, the electronic ignition lock control unit and the peripherals CAN to the left front lamp unit LED matrix control unit (E1n11) and the right front lamp unit LED matrix control unit (E2n11). The left front lamp unit LED matrix control unit then actuates the left low beams. The right front lamp unit LED matrix control unit actuates the right low beams.

Additional function requirements, high beam actuation 

IMPORTANT The electronic ignition lock control unit sends the status of circuit 15 to the front SAM control unit via 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) 

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

The steering column tube module control unit (N80) directly reads in the switch position of the combination switch and sends it to the front SAM control unit via the chassis FlexRay (Flex E), electronic ignition lock control unit and interior CAN.

The front SAM control unit evaluates the incoming information and transmits the "High beams ON" status via the interior CAN, the electronic ignition lock control unit and the user interface CAN to the instrument cluster, which then actuates the high beams indicator lamp.

IMPORTANT Vehicles with code 464 (Digital instrument cluster full display) If high beams actuation is activated, the instrument cluster switches off the low beams control message and actuates the high beams control message.

Vehicles with CODE 631 (Static left-hand traffic LED headlamp) or CODE 632 (Static right-hand traffic LED headlamp) 

The front SAM control unit sends the "High beams ON" request via interior CAN, electronic ignition lock control unit and peripherals CAN to the headlamp control units. The left headlamp control unit directly actuates the left high beam (E1e1). The right headlamp control unit directly actuates the right high beam (E2e1).

Vehicles with CODE 640 (High Performance LED) or CODE 641 (DYNAMIC LEFT-HAND TRAFFIC LED HEADLAMP) or CODE 642 (DYNAMIC RIGHT-HAND TRAFFIC LED HEADLAMP) 

The front SAM control unit transmits the "High beams ON" request via the interior CAN, the electronic ignition lock control unit and the peripherals CAN to the front lamp unit LED matrix control units. 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 84 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.

IMPORTANT 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".

Additional function requirements for daytime running lights actuation 

IMPORTANT Model 205 as of model year 2019, model 253 (except for model 253.99) as of model year 2020, with LED headlamp (dynamic), with code 498 (Japan version) or code 494 (USA version)

The head unit transmits the "Switch on daytime running lights" request via the user interface CAN, the electronic ignition lock control unit and the interior CAN to the front SAM control unit.

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

The CDI control unit (N3/9) (diesel engine) or the ME-SFI [ME] control unit (N3/10) (gasoline engine) transmits the "Engine running" or "Drivetrain operational" signal via the drive train CAN (CAN C1), the powertrain control unit (N127), the chassis FlexRay, the electronic ignition lock control unit and the interior CAN to the front SAM control unit.

The electronic stability program control unit (N30/4) sends the "standstill" signal via the chassis FlexRay, electronic ignition lock control unit and interior CAN 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 

The front SAM control unit reads in all the relevant information, evaluates it and sends the "Daytime running lights ON" request for vehicles except CODE 498 (Japan version) via interior CAN, electronic ignition lock control unit and the periphery CAN to the headlamp control units.

The left headlamp control unit directly actuates the daytime running lamps in the position light and the left daytime running light (E1e27). The right headlamp control unit actuates the daytime running light in the position light and the right daytime running light (E2e27).

IMPORTANT Model 205 as of model year 2019, model 253 (except for model 253.99) as of model year 2020, with LED headlamp (dynamic), with code 498 (Japan version)

Instead of the daytime running lights, the standing lights actuation is activated.

Depending on the ambient light situation, taillight actuation (without license plate illumination) is activated in twilight a well as daytime running lights actuation. The low beams actuation is activated as it gets darker.

The daytime running lights actuation function is not available in the following countries:

Additional function requirements for auto on/off driving lights 

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

The "Engine running" or "Drivetrain operational" signal is sent by the CDI control unit or the ME-SFI [ME] control unit to the front SAM control unit via drivetrain CAN, powertrain control unit, chassis FlexRay, electronic ignition lock control unit and interior CAN.

The electronic stability program control unit sends the "standstill" signal via the chassis FlexRay, electronic ignition lock control unit and interior CAN to the front SAM control unit.

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

Function sequence for auto on/off driving lights 

In the auto on/off driving lights, the low beams are automatically switched on or 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 at night
Start of trip Standing lamp Low beam
Transmitter key (A8/1) not in the vehicle interior Off Off
Transmitter key in the vehicle interior Off Off
Circuit 15R ON On Off
Terminal 15 ON On after t = 2 s Off
"Engine running" signal or "Drivetrain ready" signal set or "Standstill" signal not set 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 ready" signal set or "Standstill" signal not set On On (high beams permissible)
Circuit 15R ON On after t = 2 s Off
Transmitter key in the vehicle interior (driver door closed) On Off
Transmitter key in the vehicle interior (driver door open) Off Off
Transmitter key not in the vehicle interior Off Off

The low beams are automatically 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 light sensor in rain/light sensor with additional functions 

The light sensor records the ambient brightness. The rain/light sensor with additional functions reads in the signals of the light sensor directly evaluates them and transmits the "Low beams ON" request via the rain/light sensor LIN (LIN B16) to the front SAM control unit. The front SAM control unit then activates the low beams actuation.

IMPORTANT In the event of light sensor failure, the front SAM control unit activates the low beams actuation 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.

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, this is referred to as "Adverse weather light". The front SAM control unit actuates the windshield wiper system.

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

Additional function requirements, automatic HRA [LWR] 

Function sequence for automatic HRA [LWR] 

The automatic HRA [LWR] corrects the headlamp range of the vehicle headlamps in accordance with the load or the vehicle pitch motions induced by the vehicle dynamics.

Determining vehicle level on model 205: 

Vehicles without code 459 (DYNAMIC BODY CONTROL suspension with adjustable damping) and without code 483 (ADVANCED AGILITY package) and without code 489 (AIRMATIC) 

The left headlamp control unit reads in the signals of the following sensors directly for evaluating the vehicle level:

Vehicles with code 459 (DYNAMIC BODY CONTROL suspension with adjustable damping) 

The adaptive damping system control unit (N51/5) reads in the signals from the following sensors and evaluates them:

scientia non olet · About LEMON Manuals