Function Of Intelligent Light System - GF82.10-P-3090RDM

Model 172.4 as of model year 2017

with code 640 (High-performance LED)

with code 641 (Headlamps, LED, dynamic, left-side traffic)

with code 642 (Headlamps, LED, dynamic, right-side traffic)

Function requirements for Intelligent Light System function in general

No overvoltage or undervoltage (operating voltage range U ≥ 7 ≤ 17.5 V)
Transport mode not activated
Low beam ON
"Engine running" or "drive train operational" signal on
Function "Intell. Light System": activated in the "Settings", "Lights" menu in the instrument cluster

The CDI control unit (N3/9) (with diesel engine) or ME-SFI [ME] control unit (N3/10) (with gasoline engine) sends the "Engine running" or the "Drivetrain operational" signal over the chassis CAN 1 (CAN E1), front SAM control unit with fuse and relay module (N10/1) and chassis CAN 2 (CAN E2) 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 front SAM control unit reads in the status of the exterior lights switch (S1) directly, and sends the "Low beams ON" request over chassis CAN 2 to the headlamp control units.

Intelligent Light System function in 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.

While the Intelligent Light System function is actuated, the driving lights actuation is active.

The Intelligent Light System function encompasses the following subfunctions:

Cornering lights function sequence
Function sequence, dynamic curve illumination
Function sequence for active light distribution (with CODE 641 (Dynamic left-hand traffic LED headlamp) or CODE 642 (Dynamic right-hand traffic LED headlamp))

Additional function prerequisites for cornering lights

Turn signaling active and speed v < 40 km/h (except code 494 (USA version)) or v < 60 km/h (with code 494 (USA version)) or steering wheel angle recognized and speed v < 70 km/h
Radius of curve r ≤ 80 m

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 wheel angle, recorded by the steering wheel 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

Courtesy of MERCEDES-BENZ USA

The steering column tube module control unit (N80) directly reads in the data of the steering wheel angle sensor and the switch position of the combination switch and sends the data via chassis CAN 1, front SAM control unit and chassis CAN 2 to the left headlamp 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 over the chassis CAN 1, front SAM control unit and chassis CAN 2 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 headlamp control units operate in a master-slave combination whereby the left headlamp control unit acts as the master and synchronizes the right headlamp control unit over chassis CAN 2.

The right headlamp control unit evaluates all the information and, if necessary, actuates the right cornering light (E2e9).

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 wheel angle or in the turn signaling request, both corner-illuminating fog lamps 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 vehicle speed of v = 40 km/h compared with the request by the detection of the steering wheel 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.

The "reverse gear engaged" status is defined as follows.

Vehicles with transmission 711 or 716 (manual transmission):

Engagement of the reverse gear is defined through the status of the backup lamp switch (S16/2), which is read in directly by the front SAM control unit.

Vehicles with transmission 725 (automatic transmission):

The fully integrated transmission control unit (Y3/8n4) sends the status of the reverse gear via drive train CAN (CAN C), CDI control unit or ME-SFI [ME] control unit and chassis CAN 1 to the front SAM control unit. The front SAM control unit sends the "Reverse gear engaged" signal to the left headlamp control unit via chassis CAN 2.

If the cornering lights function is requested by the detected steering wheel angle at the same time as the turn signaling function, the actuation sensitivity is increased. The corresponding cornering light is actuated as soon as a curve radius of r ≤ 450 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 for dynamic curve illumination

Vehicle moving forward
Extended fog light function disabled

Function sequence, dynamic curve illumination

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

A conventional headlamp serves as a basis, the headlamp unit of which is supported in a retaining frame so that it can swivel. When steering into a curve, the headlamp unit on the inside of the curve is swiveled up to α = 15°, the headlamp unit on the outside of the curve up to α = 7.5°.

Schematic of light distribution for active dynamic curve illumination function

Courtesy of MERCEDES-BENZ USA

The dynamic curve light actuation function depends on the following control variables:

Steering wheel angle
Vehicle speed
Vehicle yaw behavior (vehicle movement)

The direct input factor is the steering wheel angle, the vehicle speed influences the function's control response (gear ratio of steering wheel angle to 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. To compensate for the natural oscillating movement of the vehicle when driving straight ahead, an area with lower sensitivity and enhanced damping has been provided (approx. ± 6° steering wheel angle).

The steering column tube module control unit directly reads in the data of the steering wheel angle sensor and sends it via chassis CAN 1, front SAM control unit and chassis CAN 2 to the left headlamp control unit.

The vehicle speed is calculated on the basis of the wheel speeds. To do so, the Electronic Stability Program control unit sends corresponding data over the chassis CAN 1, front SAM control unit and chassis CAN 2 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 the vehicle dynamics CAN (CAN H), Electronic Stability Program control unit, chassis CAN 1, front SAM control unit and chassis CAN 2 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 over chassis CAN 2. The right headlamp control unit then actuates, if necessary, the right active curve lights actuator motor (E2m2).

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.

If the curve illumination actuation is defective, the headlamp units 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 left-hand traffic LED headlamp) or CODE 642 (Dynamic right-hand traffic LED headlamp))

Vehicle moving forward

Function sequence for active light distribution

The active light distribution encompasses the following subfunctions:

Function sequence for motorway lights
Function sequence for extended fog light

Additional function requirements, freeway lights

Extended fog light function disabled
Radius of curve r ≥ 800 m

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 achieved by means of vertically deflecting the light cone and increasing the light output.

The motorway lights are activated at vehicle speeds Modelical for the freeway or expressway.

The motorway lights function is deactivated when it is raining. Rain is detected by evaluating the "Windshield wiper out of park position" signal by the front SAM control unit. If the windshield wiper is in the park position less than t = 0.6 s, this is evaluated as continuous wipe. Rain is detected if the continuous wipe function is active for t > 2 min.

Schematic of light distribution for active freeway lights function

Courtesy of MERCEDES-BENZ USA

The motorway lights function depends on the following control factors:

Steering wheel angle
Vehicle speed
Vehicle yaw behavior (vehicle movement)

The left headlamp control unit evaluates all relevant information and actuates the left low beam (short range) (E1e15) as well as the left low beam (long range) and high beam (E1e16) via the left headlamp LIN (LIN G1) and the left front actuation module, LED exterior lighting (E1n7).

The left headlamp control unit synchronizes the right headlamp control unit via chassis CAN 2. The right headlamp control unit then actuates the right low beam (short range) (E2e15) as well as the right low beam (long range) and high beam (E2e16) via the right headlamp LIN (LIN G2) and the right front actuation module, LED exterior lighting (E2n7).

From a vehicle speed of v = 90 km/h onwards and a radius of curve of r ≥ 800 m for a driving distance of more than s = 2.5 km, the light output of the corresponding actuation module, LED exterior lighting is increased linearly to P = 38 W.

The left headlamp control unit as from a vehicle 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

Rear fog lights actuation active

The front SAM control unit reads in the status of the rear fog light button (S1s10) directly and sends this over CAN 2 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 light cone of the front lamp unit facing the inside of the road is raised and steered outwards at vehicle speeds below v = 70 km/h.

Schematic of light distribution for active extended fog light function

Courtesy of MERCEDES-BENZ USA

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 headlamp unit of the left front 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 following applies for left-hand drive vehicles: 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.

The following applies to right-hand drive vehicles: The current position of the right active curve light actuator motor is detected by the right active curve light position sensor and the position of the right light distribution actuator motor is detected by the right light distribution position sensor (E2b2). The signals of the position sensors are evaluated by the right headlamp control unit.

If the extended fog light function is active, the dynamic curve illumination 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.

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:

Failure of a lamp unit (low beam)
Actuator motor malfunction

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

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