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Intelligent Light System, Function - GF82.10-P-3090LF

Model 217 

Model 222 up to model year 2018 with code 640 (SAE dynamic LED headlamps, right-hand traffic) 

Model 222 up to model year 2018 with code 641 (Dynamic LED headlamps, left-hand traffic) 

Model 222 up to model year 2018 with code 642 (Dynamic LED headlamps, right-hand traffic) 

Function requirements, general 

IMPORTANT Detailed information on transport mode is available in a function description.

The "Engine running" or "Drivetrain operational" status is sent by the CDI control unit (N3/9) (with diesel engine) or the ME-SFI [ME] control unit (N3/10) (with gasoline engine) via drive train CAN (CAN C1), powertrain control unit (N127), chassis FlexRay (Flex E), electronic ignition lock control unit (N73) and periphery CAN (CAN PER) 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 front SAM control unit (N10/6) reads in the status of the exterior lights switch (S1) directly and sends the "Low beams ON" request via interior CAN (CAN B), electronic ignition lock control unit and periphery CAN to the headlamp control units. The left headlamp control unit actuates the left low beam (short range) (E1e15) and the left low beam (long range) (E1e16) via left headlamp LIN (LIN G1) and the left front actuation module, LED exterior lighting (E1n7). The right headlamp control unit actuates the right low beam (short range) (E2e15) and the right low beam (long range) (E2e16) via right headlamp LIN (LIN G2) and the right front actuation module, LED exterior lighting (E2n7). The "Intelligent Light System" function is selected and switched on or off manually via the instrument cluster's control level. The instrument cluster sends the corresponding status via user interface CAN (CAN HMI), electronic ignition switch control unit and periphery CAN to the headlamp control units.

Intelligent Light System, general 

The Intelligent Light System function enables optimum illumination of the road to be achieved during different driving situations and weather conditions. This is achieved by increasing light output and through targeted actuation of additional light sources along with various actuators in the front lamp units.

During actuation of the Intelligent Light System function, the driving lights actuation described in the "Driving lights actuation function" is active.

The Intelligent Light System function encompasses the following subfunctions:

Additional function prerequisites for cornering lights 

Cornering lights function sequence 

The cornering lights improve the illumination of the edge of the road on the inside of the curve.

The direct input factors of the cornering lights actuation are the steering angle, recorded by the steering angle sensor (N49), and the turn signaling function, defined by the switch position of the combination switch (S4), since they describe the driver's required direction.

The vehicle speed influences the actuation characteristic for cornering lights actuation. At slow speed, a lower switch-on point is required to ensure that the cornering lights can be activated early in urban traffic.

Schematic of light distribution for active cornering lights actuation 

G15301081Courtesy of MERCEDES-BENZ USA

The steering column tube module control unit (N80) directly reads in the signals of the steering wheel angle sensor and the switch position of the combination switch and sends information on the steering angle and the switch position of the combination switch via chassis FlexRay, electronic ignition lock control unit and periphery CAN to the left headlamp control unit.

The vehicle speed is calculated on the basis of the wheel speeds. To this end, the Electronic Stability Program control unit (N30/4) sends the wheel speed signals via chassis FlexRay, electronic ignition switch control unit and periphery CAN to the left headlamp control unit. The left headlamp control unit evaluates all the information and, if necessary, actuates the left cornering light (E1e9). The right headlamp control unit actuates the right cornering light (E2e9), if necessary.

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 via periphery CAN. Only one cornering light is actuated: the light on the inside of the curve during forward travel and the light on the outside of the curve during reverse travel. If there is a rapid change in the steering angle or in the turn signaling request, both cornering lights may illuminate briefly. The corresponding cornering light is switched on and off with dimming.

The request by the turn signaling function has a higher priority below a speed of v = 40 km/h compared with the request by the detection of the steering angle in order to ensure the illumination of the edge of the road on the inside of the curve when the steering wheel is turned and turning in the opposite direction (situation at traffic circles). When the reverse gear is engaged, only the data of the steering wheel angle sensor is evaluated.

Gear range "R" is engaged by the fully integrated transmission control unit (Y3/8n4). The fully integrated transmission control unit sends the "Gear range R engaged" status to the electronic ignition lock control unit via drive train CAN, powertrain control unit and the chassis FlexRay.

The microprocessor for controlling the central gateway functions in the electronic ignition lock control unit uses the incoming information to generate the signal "Reverse gear engaged" and sends this via periphery CAN to the left headlamp control unit.

If the cornering lights function is requested simultaneously by the detected steering angle and the turn signaling function, the actuation sensitivity is increased. The corresponding cornering light is actuated as soon as a curve radius of r < 500 m is detected.

When the function request suddenly no longer exists, the corresponding cornering light remains switched on for a holding time of approx. t = 2 s and is switched off within t = 2 s with dimming.

Additional function requirements, active curve illumination 

Active curve lights, function sequence 

Active curve illumination improves the road illumination when cornering. For this the low beam cone is swiveled horizontally towards the center point of the curve.

The low beams (long range) are designed as spotlights and loosely mounted in the low beam modules. The light cone of the low beams (long range) can be swiveled both horizontally and vertically.

When steering into a curve, the low beam (long range) on the inside of the curve is swiveled up to a = 15° and the low beam (long range) on the outside of the curve up to a = 7.5°.

The position of the low beams (short range) remains unchanged.

Schematic diagram of light distruction for active function of active curve lights 

G15301082Courtesy of MERCEDES-BENZ USA

The active curve lights function is carried out depending on the following set variables:

The direct input factor is the steering angle, the vehicle speed influences the control response of the function (transformation of steering angle into swivel angle).

At a low vehicle speed, a smaller conversion is required so that the light pattern does not behave in a jumpy manner (e.g. in urban traffic). At medium vehicle speeds an immediate response is given to relatively minor changes in the steering angle and at higher vehicle speeds the responses are dampened again to a greater extent. A range with lower sensitivity and greater damping is provided (approx. ± 6° steering angle) to compensate for the natural weaving of the vehicle when traveling straight ahead.

The steering column tube module control unit reads in the signals of the steering wheel angle sensor directly and sends information on the steering angle via chassis FlexRay, electronic ignition lock control unit and periphery CAN to the left headlamp control unit.

The vehicle speed is calculated on the basis of the wheel speeds. To this end, the Electronic Stability Program control unit sends the wheel speed signals via chassis FlexRay, electronic ignition switch control unit and periphery CAN to the left headlamp control unit.

The yaw behavior of the vehicle is detected by the turn rate sensor for lateral and longitudinal acceleration (B24/15). This sends corresponding information over via dynamics CAN (CAN H), Electronic Stability Program control unit, chassis FlexRay, electronic ignition lock control unit and periphery CAN to the left headlamp control unit.

The left headlamp control unit evaluates all relevant information and, if necessary, actuates the left active curve lights actuator motor (E1m2). The left headlamp control unit synchronizes the right headlamp control unit via periphery CAN. The right headlamp control unit actuates the right active curve light actuator motor (E2m2), if necessary.

The current position of the left active curve light actuator motor is detected by the left active curve light position sensor (E1b1) and the position of the right active curve light actuator motor is detected by the right active curve light position sensor (E2b1). The signals of the active curve lights position sensors are evaluated by the respective headlamp control unit.

IMPORTANT If the curve illumination actuation is defective, the low beams modules are, if possible, swiveled into the central position. If an active curve lights actuator motor malfunctions, the left light distribution actuator motor (E1m3) or the right light distribution actuator motor (E2m3) is actuated to cover up the rising part of the light-dark boundary and thereby reduce the glare for oncoming traffic.

Additional function requirement for active light distribution (with CODE 641 (Dynamic headlamp LED for left-hand traffic) or CODE 642 (Dynamic headlamp LED for right-hand traffic)) 

Function sequence for active light distribution 

The active light distribution encompasses the following subfunctions:

IMPORTANT Vehicles with code 610 (Night View Assist)

The spotlight function can also influence the active light distribution if, for example, a person is detected in the dark by the Night View Assist function. Further information here can be found in a separate function description.

Additional function requirements, freeway lights 

Function sequence for motorway lights 

The freeway lights improve the illumination of the road by increasing the range of the low beams without blinding the preceding traffic.

This function is implemented by means of vertically deflecting the light cone and increasing the light output.

The freeway lights are activated at speeds typical for the freeway or expressway.

IMPORTANT Hi The motorway lights function is deactivated when it is raining. Rain is detected by evaluating the "Windshield wiper out of park position" signal. If the windshield wiper is in the park position for less than t = 600 ms, this is evaluated as continuous wipe. Rain is detected if the continuous wipe function is active for t > 2 min. The front SAM control unit actuates the windshield wiper system.

Schematic of light distribution for active freeway lights function 

G15301083Courtesy of MERCEDES-BENZ USA

The motorway lights function is carried out depending on the following set variables:

The steering column tube module control unit reads in the signals of the steering wheel angle sensor directly and sends information on the steering angle via chassis FlexRay, electronic ignition lock control unit and periphery CAN to the left headlamp control unit.

The vehicle speed is calculated on the basis of the wheel speeds. To this end, the Electronic Stability Program control unit sends the wheel speed signals via chassis FlexRay, electronic ignition switch control unit and periphery CAN to the left headlamp control unit.

The yaw behavior of the vehicle is detected by the turn rate, lateral acceleration and longitudinal acceleration sensor. This sends corresponding information via vehicle dynamics CAN, Electronic Stability Program control unit, chassis FlexRay, electronic ignition lock control unit and periphery CAN to the left headlamp control unit.

The left headlamp control unit evaluates all relevant information and actuates the left low beam (short range) and the left low beam (long range) via the left headlamp LIN and the left front actuation module, LED exterior lighting.

The left headlamp control unit synchronizes the right headlamp control unit via periphery CAN. The right headlamp control unit then actuates the right low beam (short range) and the right low beam (long range) via the right headlamp LIN and the right front actuation module, LED exterior lighting.

As of a vehicle speed of v = 90 km/h and a curve radius of r > 800 m for a driving distance greater than s = 2.5 km, the light output of the low beams (long range) is increased. The light output of the low beams (short range) remains unchanged. To do so, the respective headlamp control unit sends the request for "Increase light output" via headlamp LIN to the respective front actuation module, LED exterior lighting, which then actuates the low beams (long range) with higher output.

The left headlamp control unit as from a speed of v = 110 km/h and a curve radius of r > 800 m for more than s = 1 km driving distance, actuates the left headlamp range adjustment actuator motor (E1m1). The headlamp unit of the left front lamp unit is raised. The range of the low beams is thus increased. The maximum lift is reached at v = 130 km/h. If the vehicle speed drops down to below v = 80 km/h, the "motorway lights" function is disabled.

Additional function requirements for extended fog light function 

IMPORTANT The front SAM control unit reads in the status of the rear fog light button (S1s10) directly and sends the status "Rear fog light ON" via interior CAN, electronic ignition lock control unit and periphery CAN to the left headlamp control unit.

Function sequence for extended fog light 

The extended fog light function improves the illumination of the edges of the road and reduces the internal dazzling.

The low beams module in the front lamp unit facing the inside of the road is raised and swiveled outwards at speeds below v = 70 km/h.

Schematic of light distribution for active extended fog light function 

G15301084Courtesy of MERCEDES-BENZ USA

The vehicle speed is calculated on the basis of the wheel speeds. To this end, the Electronic Stability Program control unit sends the wheel speed signals via chassis FlexRay, electronic ignition switch control unit and periphery CAN to the left headlamp control unit.

The left headlamp control unit evaluates all of the relevant information and actuates the left light distribution actuator motor and the left active curve lights actuator motor. The low beam module in the front left lamp unit is swiveled outwards by α = 8° and the part of the light-dark boundary that slopes upward to the right is covered. Internal dazzling is reduced and illumination of the road surface at the side is improved.

The current position of the left active curve light actuator motor is detected by the left active curve light position sensor and the position of the left light distribution actuator motor is detected by the left light distribution position sensor (E1b2). The signals of the position sensors are evaluated by the left headlamp control unit.

IMPORTANT If the extended fog light function is active, the active curve lights function is deactivated.

If the high beams function is requested while the "Extended fog light function" is active, the position of the headlamp unit is retained.

IMPORTANT The daytime running lamps are switched off because of the possible dazzling effect involved.

The extended fog light function is deactivated under the following conditions:

IMPORTANT When testing and adjusting the front lamp unit, ensure that the extended fog light function is not active.

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