(Headlamp Control, Function - GF82.10-P-2009GR)
Model 166
up to Model year 2016
without CODE 615 (Bi-xenon headlamp unit with integrated curve illumination)
without CODE 621 (Intelligent Light System (left-hand traffic))
without CODE 622 (Intelligent Light System (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.
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 headlamp range adjustment (HRA [LWR])
The driving lights are actuated corresponding to the position of the exterior lights switch (S1). The SAM control unit (N10) 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) transmits the status of circuit 15 to the SAM control unit via the interior CAN (CAN B).
The standing lights are active during low beams actuation. The standing lights actuation is described in the separate document "Standing/parking lights actuation function".
Function sequence for low beam actuation
Turning the exterior lights switch to the "Manual driving lights" position requests actuation of the low beams.
The SAM control unit reads in the status of the exterior lights 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).
The SAM control unit also then the request "Low beams indicator lamp On" over interior CAN to the instrument cluster (A1), which then actuates the low beams indicator lamp (A1e67).
Additional function requirements for high beam actuation
- For high beams function: Circuit 15 and low beams On
- For headlamp flasher function: Circuit 15R On
The electronic ignition lock control unit transmits the circuit 15 status via the interior CAN to the SAM control unit.
Function sequence for high beam actuation
The high beams actuation function comprises 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) directly reads in the switch position of the combination switch and sends this via chassis CAN 1 (CAN E1), electronic ignition lock control unit and interior CAN to the SAM control unit.
The front SAM control unit receives the switch position of the combination switch, actuates the left high beam (E1e1) and right high beam (E2e1) directly and sends the status of the high beams via interior CAN to the instrument cluster. The instrument 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".
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
Function sequence for daytime running lights actuation
The instrument cluster transmits the "Daytime running lights ON" request depending on the national coding or manually via 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 1, electronic ignition lock control unit and the interior CAN to the SAM control unit. The vehicle speed is calculated on the basis of the wheel speeds. To do so, the Electronic Stability Program control unit (N30/4) sends corresponding data via chassis CAN 1, electronic ignition lock control unit and chassis CAN 2 (CAN E2) to the instrument cluster. The instrument cluster calculates the vehicle speed and sends this to the SAM control unit over interior CAN.
The SAM control unit reads in all relevant information, evaluates it and actuates the left daytime running light headlamp (E1/3) and right daytime running light headlamp (E2/3) on vehicles except CODE 498 (Japan version). In vehicles with CODE 498 (Japan version), the low beams are actuated to output the daytime running lights function; the daytime running light headlamps are only used as position lamps.
When it is dark, the SAM control unit activates the low beams actuation and in vehicles with CODE 494 (USA version) or CODE 460 (Canada version) actuates the daytime running light headlamps at reduced power. On vehicles except CODE 494 (USA version) and except CODE 460 (Canada version), the SAM control unit switches the daytime running light headlamps off.
The low beams actuation is described in more detail in the chapter "Low beams actuation".
The ambient brightness is recorded by the rain/light sensor (B38/2). The SAM control unit reads in the signals of the rain/light sensor (dimness stage) via the roof LIN (LIN B13).
The daytime running lights actuation is deactivated as soon as the exterior lights switch is turned to the "Standing lights", "Manual driving lights" or "Left parking light" or "Right parking light" position.
On vehicles with CODE 460 (Canada version), the daytime running lights actuation is switched off after t = 3 min with the vehicle at a standstill. When the vehicle then starts to move again, the SAM control unit automatically activates daytime running lights actuation.
The daytime running lights actuation has 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 permissible only when the driving lights are manually switched on via the exterior lights switch (except CODE 460 (Canada version) or except 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
- Rain/light sensor signals "Darkness detected"
The CDI control unit or the ME-SFI [ME] control unit transmits the "Engine running" or "Drivetrain operational" signal via chassis CAN 1, the electronic ignition lock control unit and the interior CAN to the SAM control unit.
The instrument cluster transmits the vehicle speed to the SAM control unit via the interior CAN.
The 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 | ||
| 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 ready" signal set or v > 3 km/h | On | On (high beams permissible) |
| End of trip | Standing lamp | Low beam |
| "Engine running" signal or "Drivetrain ready" 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 windshield wiper activities
Function sequence for auto on/off driving lights over rain/light sensor
The rain/light sensor evaluates the ambient brightness. The SAM control unit reads in the signals of the rain/light sensor via roof LIN and activates the low beams actuation if darkness is recognized.
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 windshield 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 SAM control unit controls the windshield wiper system and evaluates the signals 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 SAM control unit activates low beams 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 for headlamp range adjustment
- Driving lights On (low beam/high beam)
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).
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.
The power supply is provided through the SAM control unit and it is switched through to the headlamp range adjustment actuator motors corresponding to the position of the headlamp range adjuster.
The left headlamp range adjustment actuator motor moves the headlamp unit in the left front lamp unit.
The right headlamp range adjustment actuator motor moves the headlamp unit in the right front lamp unit.
| Electrical function schematic for driving lights actuation | PE82.10-P-2059-97NAA | ||
| Overview of exterior lights system components | GF82.10-P-9998GR |