Headlamp Control, Function - GF82.10-S-2009TRD
Model 447.6/7
except code LG2 (LED Intelligent Light System)
except code XM0 (Facelift)
Model 448.7
except code LG2 (LED Intelligent Light System)
Function requirements, general
- No overvoltage or undervoltage (operating voltage range from 11.0 to 15.5 V)
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:
- 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 headlamp range adjustment (HRA [LWR])
The electronic ignition lock (EZS) control unit (N73) sends the status of circuit 15 via interior CAN (CAN B) to the signal acquisition and actuation module (SAM) control unit (N10/1).
The driving lights are actuated corresponding to the position of the illumination switch (S1). The signal acquisition and actuation module (SAM) control unit directly reads in the status of the illumination switch.
Additional function requirements for low beams actuation
- Circuit 15 ON
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 illumination switch into the "low beams" position requests actuation of the low beams.
The signal acquisition and actuation module (SAM) control unit reads in the status of the illumination switch directly 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) directly.
The signal acquisition and actuation module (SAM) control unit also sends the "Low beams indicator lamp" request via interior CAN to the instrument cluster (IC [KI]) control unit (A1/1), which then actuates the low beams indicator lamp (A1/1e67).
Additional function requirements, high beam actuation
- For high beams function: circuit 15 ON and low beams ON
- For headlamp flasher function: Circuit 15R On
Function sequence for high beam actuation
The high beams actuation 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 (MRM) control unit (N80) directly reads in the switch position of the combination switch and sends this via the chassis CAN (CAN E), electronic ignition lock (EZS) control unit, and interior CAN to the signal acquisition and actuation module (SAM) control unit.
The signal acquisition and actuation module (SAM) control unit receives the switch position of the combination switch and actuates the left high beam (E1e1) and the high beam (E2e1) directly.
The signal acquisition and actuation module (SAM) control unit also sends the "High beams, actuation" status via interior CAN to the instrument cluster (IC [KI]) control unit, which then actuates the high beams indicator lamp (A1/1e3).
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 30 s. Then the pending request is interpreted as a "stuck combination switch" and the actuation of the high beams is terminated.
Additional function requirements for daytime running lights actuation
- "Daytime running lights" function activated in "Settings", "Light" menu in instrument cluster (IC) control unit
- "Engine running" signal
- Illumination switch in "AUTO" position
The instrument cluster (IC [KI]) control unit sends the "Daytime running lights ON" request to the signal acquisition and actuation module (SAM) control unit via interior CAN.
The CDI control unit (N3/33) (with engine 651) or the ME-SFI [ME] control unit (N3/34) (with engine 274) or the CDI control unit (N3/36) (with engine 622) transmits the "Engine running" signal via the chassis CAN, the electronic ignition lock (EZS) control unit and the interior CAN to the signal acquisition and actuation module (SAM) control unit.
The signal acquisition and actuation module (SAM) control unit directly reads in the status of the illumination switch.
Function sequence for daytime running lights actuation
The signal acquisition and actuation module (SAM) control unit reads in all relevant information, evaluates it and actuates the left daytime running light (E1e7) in the left front lamp unit and the right daytime running light (E2e7) in the right front lamp unit directly.
The daytime running lights actuation is deactivated as soon as the illumination switch is turned to the standing light, manual driving lights, left parking light or right parking light position.
Additional function requirements for auto on/off driving lights
- "Engine running" signal
- Illumination switch in "AUTO" position
The CDI control unit or ME-SFI [ME] control unit transmits the "Engine running" signal via the chassis CAN, the electronic ignition lock (EZS) control unit and the interior CAN to the signal acquisition and actuation module (SAM) control unit.
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 merely 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 in daylight | |||
|---|---|---|---|
| Start of trip | Standing lamp | Daytime running lamps | Low beam |
| Circuit 15C OFF | OFF | OFF | OFF |
| Circuit 15C ON | OFF | OFF | OFF |
| Circuit 15R ON | OFF | OFF | OFF |
| Circuit 15 ON | OFF | OFF | OFF |
| "Engine running" signal | OFF | ON | OFF |
| End of trip | Standing lamp | Daytime running lamps | Low beam |
| "Engine running" signal | OFF | ON | OFF |
| Circuit 15R ON | OFF | OFF | OFF |
| Circuit 15C ON (driver door closed) | OFF | OFF | OFF |
| Circuit 15C ON (driver door open) | OFF | OFF | OFF |
| Circuit 15C OFF | OFF | OFF | OFF |
| 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 |
| Circuit 15 ON | ON | OFF |
| "Engine running" signal | 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 | 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 humidity and light sensor (B38) (with code LA2 (Headlamp Assist)) or via humidity sensor/light sensor/rain sensor (B38/2) (with code JF1 (Rain sensor)) or via humidity sensor/light sensor/rain sensor/sun sensor (B38/3) (with code HH4 (THERMOTRONIC automatic air conditioning))
- Function sequence for auto on/off driving lights over wiper activities
Function sequence for auto on/off driving lights via humidity and light sensor (B38) (with code LA2 (Headlamp Assist)) or via humidity sensor/light sensor/rain sensor (B38/2) (with code JF1 (Rain sensor)) or via humidity sensor/light sensor/rain sensor/sun sensor (B38/3) (with code HH4 (THERMOTRONIC automatic air conditioning))
The ambient brightness is detected by the humidity and light sensor or the humidity sensor/light sensor/rain sensor or humidity sensor/light sensor/rain sensor/sun sensor. This sensor reads in the signals, evaluates them and sends a signal via the roof LIN (LIN B13) to the signal acquisition and actuation module (SAM) control unit. The signal acquisition and actuation module (SAM) control unit evaluates this signal and activates the low beams actuation.
In the event of failure of the humidity and light sensor or the humidity sensor/light sensor/rain sensor or the humidity sensor/light sensor/rain sensor/sun sensor, 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 signal acquisition and actuation module (SAM) control unit controls the windshield wiper system.
If the windshield wiper system is activated for more than 20 s with a wipe cycle time of less than 6 s, the signal acquisition and actuation module (SAM) control unit activates the low beams actuation. If there are no wipe cycles for 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 60 s.
Detailed information on the wiper startup suppression function can be found in the document "Windshield wipe, function".
Additional function requirements for headlamp range adjustment (HRA [LWR])
- Driving lights ON (low beam or high beam)
Function sequence for headlamp range adjustment (HRA [LWR])
The HRA [LWR] is installed as an item of passive safety equipment to prevent oncoming traffic from being dazzled.
The incline angle of the driving lights can be corrected by operating the headlamp range controller (S1s8).
The signal acquisition and actuation module (SAM) control unit directly actuates the left headlamp range adjustment actuator motor (E1m1) and the right headlamp range adjustment actuator motor (E2m1).
The left headlamp range adjustment actuator motor adjusts the headlamp unit in the left front lamp unit.
The right headlamp range adjustment actuator motor adjusts the headlamp unit in the right front lamp unit.
| Electrical function schematic for driving lights actuation | Model 448.7 except code LG2 (LED Intelligent Light System) | PE82.10-S-2059-97VDD | |
| Model 447.6/7 except code LG2 (LED Intelligent Light System) except code XM0 (Facelift) | PE82.10-S-2059-97TRD | ||
| Overview of exterior lights system components | GF82.10-S-9998TRA |