Headlamp Control, Function - GF82.10-P-2009RR
Model 190
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.
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])
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) reads in the status of the exterior lights switch directly.
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).
During low beams actuation, the standing light actuation is active, this is described in the "Standing/parking lights actuation function" document.
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 directly reads in the status of the exterior lights switch and sends the "Low beams On" request via the chassis CAN 2 (CAN E2) to the left headlamp control unit (E1n9) at the left front lamp unit (E1) and to the right headlamp control unit (E2n9) at 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).
The front SAM control unit also sends the "Low beams indicator lamp On" request via the interior CAN, AMG gateway control unit (N93/9), and user interface CAN (CAN HMI) to the instrument cluster (A1), which then actuates the low beams indicator lamp (A1e67).
Additional function requirements, high beam actuation
- For high beams function: Circuit 15 and low beams On
- For headlamp flasher function: Terminal 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 partial function is comprised of the following subfunctions:
- Function sequence for high beams
- 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) reads in the switch position of the combination switch directly and sends this via chassis CAN 1 (CAN E1) to the front SAM control unit.
The front SAM control unit sends the "High beams On" request via the chassis CAN 2 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).
The front SAM control unit also sends the "High beams ON" status via the interior CAN, AMG gateway control unit, and user interface CAN to the instrument cluster, which then 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".
Additional function requirements for daytime running lights actuation
- "Daytime running lights" function in the "Settings", "Light" menu is activated in the instrument cluster (except vehicles with CODE 460 (Canada version))
- "Engine running" or "Drive train ready" signal set or vehicle speed v > 3 km/h
Function sequence for daytime running lights actuation
The front SAM control unit reads in all relevant information, evaluates it, and sends the "Daytime running lights On" request on vehicles except CODE 498 (Japan version) via the chassis CAN 2 to the headlamp control units.
- Exterior lights switch in auto on/off driving lights position (on vehicles except CODE 460 (Canada version)) or exterior lights switch in left parking light or right parking light position (on vehicles with CODE 460 (Canada version))
The instrument cluster sends the "Daytime running lights ON" request depending on the country coding or activated manually via the "Settings", "Light" menu via the user interface CAN, AMG gateway control unit, and interior CAN to the front SAM control unit.
The ME-SFI [ME] control unit (N3/10) sends the "Engine running" or "Drivetrain operational" signal via the drive train CAN (CAN C1), powertrain control unit (N127), and chassis CAN 1 to the front SAM control unit.
The instrument cluster sends the vehicle speed via the user interface CAN, AMG gateway 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.
MODEL 190
with CODE 498 (Japanese version)
Instead of the daytime running lights, the low beams actuation is activated.
The left headlamp control unit directly actuates the daytime running lamps in the left parking light and daytime running light (E1e13).
The right headlamp control unit directly actuates the daytime running lamps in the right parking light and daytime running light (E2e13).
MODEL 190
with CODE 460 (Canada version)
When the vehicle is stationary, the daytime running lights actuation is switched off after a time interval of t = 3 minutes has lapsed. When the vehicle then starts to move again, the front SAM control unit automatically activates daytime running lights actuation.
Additional function requirements for auto on/off driving lights
- "Engine running" or "Drive train ready" signal set or vehicle speed v > 3 km/h
- Exterior lights switch in auto on/off driving lights position
The ME-SFI [ME] control unit sends the "Engine running" or "Drivetrain operational" signal via the drive train CAN, powertrain control unit, and chassis
CAN 1 to the front SAM control unit.
The instrument cluster sends the vehicle speed via the user interface CAN, AMG gateway 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 |
| Circuit 15C OFF | Off | Off |
| Circuit 15C ON | Off | Off |
| Circuit 15R ON | On | Off |
| Terminal 15 ON | On | Off |
| "Engine running" or "drive train operational" signal set or vehicle speed 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" or "drive train operational" signal set or vehicle speed 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 via rain/light sensor (B38/2)
- Function sequence for auto on/off driving lights over wiper activities
Function sequence for auto on/off driving lights over rain/light sensor
The ambient brightness is sensed by the rain and light sensor.
The rain/light sensor sends information on the ambient brightness (twilight level) via the wiper/inside rearview mirror LIN (LIN 2) to the front SAM control unit.
The front SAM control unit activates low beam actuation when it is dark.
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.
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 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.
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]
- Driving lights On (low beam/high beam)
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.
The left headlamp control unit directly reads in the signal from the left rear level sensor (B22/7) and left front level sensor (B22/8).
Zero-point programming is performed at the end of production to compensate for suspension 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.
When the vehicle is accelerated, the "dynamic mode" is activated and the reaction time of the automatic headlamp range adjustment is significantly reduced.
The "dynamic mode" is activated depending on the speed change and additional signals from the brake and accelerator pedal positions.
When the vehicle is standing automatic headlamp range adjustment is accomplished in the "dynamic mode".
The headlamp control units operate in a in master-slave combination, whereby the left headlamp control unit acts as the master and synchronizes the right headlamp control unit.
The left headlamp control unit actuates the left headlamp range adjustment actuator motor (E1m1) directly.
The right headlamp control unit actuates the right headlamp range adjustment actuator motor (E2m1) directly.
| Electrical function schematic for driving lights actuation | PE82.10-P-2059-97HBA | ||
| Overview of exterior lights system components | GF82.10-P-9998RR |