Table of Contents E70 Adaptive Headlight System (AHL) Subject Page Introduction .4 Legal Requirement .5 System Overview .6 System Circuit Diagram .6 System Components.9 Control Units.9 Footwell Module.10 Car Access System 3 .10 Dynamic Stability Control .10 Rain/driving Lights/Solar Sensor .10 Roof Functions Center .10 Vertical Dynamics Management .10 Bi-Xenon Headlight.11 Rain/Driving Lights/Solar Sensor.11 Roof Functions Center .11 Ultrasonic Passenger-Compartment Sensor.11 Advanced Crash Safety Management (ACSM) .11 Swivel Module for Bi-Xenon Headlight.11 Stepper Motor Controller .12 Side Light/Daytime Driving Light.12 Lights Operating Unit.12 Direction Indicator/High Beam Switch.12 Sensors .13 Yaw Rate Sensor.13 Rotation Rate Sensor.13 Steering Angle Sensor .13 Front and Rear Ride-Height Sensors .13 Brake Pedal Switch .13 Bus Systems .14 Chassis CAN .14 BodyCAN .14 LIN-Bus .14 Turn-Off Light.15 Schematic Circuit Diagram - Turn-Off Light.16 Initial Print Date: 10/06 Revision Date: Subject Page Fog Lights.19 Design of Fog Light.19 Turn-Off Light Reflector .19 Check Control M essage .19 Principles of Operation.20 Headlight Swivel Movement.20 Preconditions forthe adaptive headlight .20 Switch-On Conditions.20 Switching On Adaptive Headlight.21 Function Indicator.21 Reference Run .21 Zero Position Sensor.21 Mechanical Stop.22 Differential Angle .22 Optical Axis .22 Swivel Range.22 Swivel Direction .22 Traverse Rate.22 Swivelling .23 Stepper Motor Controller .24 Zero Position of Swivel Module.25 Switch-Off Conditions.25 AfterunningTime .25 Service Information.26 Replacing Components .26 Footwell Module.26 Stepper Motor Controller .26 Bi-Xenon Headlight .26 Diagnosis.27 Malfunction .27 Diagnosis M ode .28 Adaptive Headlight System Model: E70 Production: From Start of Production IBIICT1UIS After completion of this module you will be able to: • Explain the operation of the adaptive headlight system • Know what components contribute to the adaptive headlamp system 3 E70 Adaptive Headlight System Introduction The adaptive headlights (AHL) is available as standard equipment.This system is installed only in connection with the bi-xenon headlight. T he adaptive headlight performs the exterior lighting functions. It also enables the bi-xenon low beam and high beam headlight to move within the driving range while cornering. The AHL feature requires the following: • Rain/driving light/solar sensor • Bi-xenon headlight The swivel range of the bi-xenon low beam and high beam headlight is continuously adapted while cornering. The illuminated area while cornering therefore improves the field of view for the driver. The adaptive illumination while cornering results in: • Safer cornering with faster recognition of obstacles • Improved perception of surroundings • Accident avoidance The electronic module of the adaptive headlight facilitates faster response to the current road situation. The system is controlled by the electronic module and is therefore less susceptible than a pure mechanical systems. In addition, an emergency program can be activated via the electronic module. Note: The adaptive headlight system is derived from the E90.Thefootwell module is therefore the central control unit for the adaptive headlight. The adaptive headlight has been adapted for use in the E70. 4 E70 Adaptive Headlight System Legal Requirement The swivel movement of the adaptive headlight is permitted within certain limits to pro¬ tect oncoming traffic, i.e. to ensure oncoming traffic is not dazzled by the headlights. The vehicle moves on a circular path when the driverturns the steering wheel. The circu¬ lar path is defined by the movement of the wheels and the angle position of the front wheels. In order not to dazzle the oncoming traffic, the salient point of the light/dark limit of the headlight must not be left of the circular path at a distance corresponding to 100 times the installation height of the headlight. This conclusion forthe light/dark limit refers to right-hand drive traffic. The conclusion relating to the light/dark limit applies symmetrically to left-hand drive traffic. Index Explanation 1 Anticipated curve 2 Steering lock 3 Steering lock 5 E70 Adaptive Headlight System System Overview System Circuit Diagram 6 E70 Adaptive Headlight System Index Explanation Index Explanation i—1 Main headlight, left 7 Footwell module FRM 2 Front fog light, left 8 J unction box control unitj B 3 Frontfog light, right F-CAN Chassis CAN 4 M ain headlight, right K-CAN Body CAN 5 Connection, ride-height sensors LIN-Bus Local Interconnect Network bus 6 Lights operating unit KL 30 Terminal 30 Main Headlight - Adaptive Headlight, (1 and 4) • Side light • Low beam headlight • High beam • Direction indicator • Daytime driving lights • High beam shutter, bi-xenon • Stepper motor, headlight vertical aim control • Stepper motor for adaptive headlight Lights operating unit, item number 7 • Light switch • Fog light button • Rearfog light button • Manual headlight vertical aim control Concerning item number 5: On vehicles with vertical dynamics management, the information relating to the vehicle K-CAN signals atfootwell module 7 E70 Adaptive Headlight System K-CAN Signals at the Footwell Module In/out Information Source/sink Function In Road speed Wheel speed sensor> dynamic stability control Calculation of anticipated curve radius in con¬ nection with yaw rate Out Adaptive head¬ light defective Stepper motor controller > footwell module Check control message in instrument cluster Out Fault - adaptive headlight Footwell module Check control message in instrument cluster F-CAN signals at the Footwell Module In/out Information Source/sink Function In Steering angle Steering angle sensor > steering column switch cluster Swivel movement of adaptive headlight In Yaw rate Yaw rate sensor > dynamic stability control Calculation of anticipated curve radius in con¬ nection with vehicle speed In Vehicle level VDM sensors > vertical dynamics management FIeadlight vertical aim control 8 E70 Adaptive Headlight System System Components Depending on the equipment configuration of the vehicle, the following system compo¬ nents may be installed forthe adaptive headlight function. • Control units - Footwell module - Car Access System 3 - Dynamic stability control - Rain/driving lights/solar sensor - Rooffunctions center - Vertical dynamics management • Bi-xenon headlight • Lights operating unit • Direction indicator/high beam switch • Sensor systems - Yaw rate sensor, steering angle sensor - Front and rear ride-height sensors - Brake pedal switch Control Units The footwell module is the central control unit forthe entire exterior lighting system and therefore also forthe adaptive headlight. The other control units such as the dynamic stability control provide input signals. Control Unit Signal Car Access System 3 Wake-up Dynamic stability control Vehicle speed and yaw rate Rain/driving lights/solar sensor Switch on lights when dark Rooffunctions center Transfer of RLSS signal to K-CAN Vertical dynamics management Vehicle level 9 E70 Adaptive Headlight System Footwell Module The control forthe adaptive headlight is located in the footwell module. The footwell module is connected to three bus systems, The bus systems are: • K-CAN • F-CAN, e.g. if vertical dynamics management is installed • LIN-bus Data from the vertical dynamics management system are received via the F-CAN. The footwell module receives and sends data via the K-CAN and LIN-bus. Note: The footwell module has no gateway forthe F-CAN, however, it does have the gateway between K-CAN and LIN-bus. Car Access System 3 The Car Access System 3 sends the wake-up signal to the control unit in the vehicle. The steering column switch cluster is connected directly to the wake-up line. Dynamic Stability Control The dynamic stability control sends signals relating to the yaw rate and vehicle speed to the adaptive headlight. Rain/driving Lights/Solar Sensor The rain/driving lights/solar sensor sends the requestto switch on the low beam head¬ lights as soon as it detects low light levels (darkness). The light switch must be set to automatic high beam control forthis purpose. Roof Functions Center The roof functions center receives the signals from the rain/driving light/solar sensor. The roof functions center makes the signals available on the K-CAN. Vertical Dynamics Management Vertical dynamics management makes available the values for the dynamic headlight ver¬ tical aim control to the footwell module. The footwell module receives these values via the F-CAN. In this way the headlight range can be adapted to the different driving situations, e.g. laden/unladen. 10 E70 Adaptive Headlight System Bi-Xenon Headlight Each bi-xenon headlight contains following components: • Swivel module for bi-xenon headlight • Stepper motor controller • Stepper motorfor headlight vertical aim control • Side light corona/daytime driving light corona • Direction indicator • Bi-xenon control unit Rain/Driving Lights/Solar Sensor The rain/driving lights/solar sensor is fitted in the mirror base. The signals from the rain/driving lights/solar sensor are used to switch on the automatic driving lights. Roof Functions Center The rooffunctions centeris the gateway forthe rain/driving lights/solar sensor. It transfers the LIN-bus signal of the rain/driving lights/solar sensor to the K-CAN. Ultrasonic Passenger-Compartment Sensor The ultrasonic passenger compartment sensor signals the visual alarm of the anti-theft alarm system via the K-CAN.The visual alarm depends on the country-specific version. Note: The ultrasonic passenger compartment sensor is integrated in the roof functions center. Advanced Crash Safety Management(ACSM) The advanced crash safety management sends signals in the event of an accident. This allows the footwell module to triggerthe visual signalling (e.g. hazard warning lights ON). Swivel Module for Bi-Xenon Headlight Among otherthings, the swivel module contains following components: • Bi-xenon lamp • Hall sensorforzero position • Stepper motor 11 E70 Adaptive Headlight System The bi-xenon headlight control unit is mounted on the bi-xenon headlight. It supplies the power and ignition voltage for the bi-xenon light bulb. The bi-xenon light bulb is integrated in the swivel section of the adaptive headlight. The zero position Hall sensor registers the zero position of the swivel module. The stepper motor provides the swivel movement of the swivel module. A separate step¬ per motor is installed for the headlight vertical aim control. Stepper Motor Controller The stepper motor controller is mounted on the side of the bi-xenon headlight. The stepper motor controller controls and monitors the movement of the stepper motors for the adaptive headlight and the vertical aim control system. Side Light/Daytime Driving Light The side light/daytime driving light is designed as a fiber optics light guide ring. A 35 W bulb (H8) supplies the lightto the fiber optics ring from below. Lights Operating Unit The light switch must be set to automatic driving lights control in orderto switch on the adaptive headlight. The lights operating unit is connected to the footwell module. The light switch can be pressed in at a certain pressure in forward direction. This increas¬ es the impact surface area in the vicinity of the light switch in the event of an accident thus contributing to improved passenger protection. Direction Indicator/High Beam Switch The steering column switch cluster contains the direction indicator/high beam switch. The steering column switch cluster makes available the signal from the direction indica¬ tor/high beam switch hard-wired to the footwell module. A more detailed description of the steering column switch cluster can be found in the Product Information "Steering column switch cluster E70". 12 E70 Adaptive Headlight System Sensors Yaw Rate Sensor The yaw rate sensor makes available signals relating to the yaw of the vehicle about the vertical axis. The yaw rate sensor is installed on the driveshaft tunnel between the driver's and pas¬ senger's seat next to the advanced crash safety management ACS M. Rotation Rate Sensor The rotation rate sensors supply the signals forthe vehicle speed. The dynamic stability control evaluates the sensor of each wheel. Steering Angle Sensor The steering angle sensor is integrated in the steering column switch cluster. It is an opti¬ cal sensor and makes available data relating to the steering wheel lock angle. A more detailed description of the steering angle sensor can be found in the Product Information "Steering column switch clusterE70". Frontand RearRide-HeightSensors The signals of the ride-height sensors are used forthe headlight vertical aim control LWR. The ride-height sensors are connected directly to the footwell module. Note: If vertical dynamics management is installed, the information relating to the vehicle ride height is made available via the F-C AN. Brake Pedal Switch The signal of the brake pedal switch is used forthe headlight vertical aim control (LWR). 13 E70 Adaptive Headlight System Bus Systems The footwell module is connected to three bus systems, via which the adaptive headlight receives input signals. The bus systems are: • Chassis-CAN F-CAN • Body-CAN K-CAN • Local Interconnected Network Bus (LIN-Bus) Chassis CAN The F-CAN is connected to the footwell module forthe purpose of transferring data from the steering angle sensor. The signal path runs from the steering angle sensor in the steering column switch clustervia the F-CAN to the dynamic stability control, which in turn transfers the signal to the F-CAN. If vertical dynamics management is installed, the footwell module receives the data forthe dynamic headlight vertical aim control via the F-CAN. The data transferrate is 500 kBd. BodyCAN The footwell module receives information, e.g. "Terminal 15 ON", which is important for operation of the adaptive headlight, via the K- CAN. The K-CAN has a data transfer rate of 100 kBd. LIN-Bus The LIN-bus has a data transfer rate of 19.2 kBd. It connects the stepper motor con¬ trollers to the footwell module. 14 E70 Adaptive Headlight System Turn-Off Light The turn-off lightfunction is available only in connection with the option SA 524 Adaptive Headlight. In addition to the adaptive headlight, the turn-off light additionally illuminates the area in front of and beside the vehicle. The turn-off light makes it possible to recognize persons or traffic situations earlier in the turn-off area. Parameters such as the steering angle and vehicle speed are taken into accountforthe turn-off light func¬ tion. The turn-off light is integrated in the fog lights. This is due to the fact that the installation position of the headlights in the X5 is too high forthe turn-off light function and would not conform to legal requirements. The turn-off lightfunction is integrated in the fog light. This function is active only in position "A" of the light switch. Illumination with Turn-Off Light Index Explanation Index Explanation 1 Without Cornering Lights 2 With Cornering Lights On 15 E70 Adaptive Headlight System Schematic Circuit Diagram - Turn-Off Light 16 E70 Adaptive Headlight System Legend forSchematic Circuit Diagram - Turn-Off Light Index Explanation Index Explanation 1 M ain headlight, left 7 Lights operating unit 2 Front fog light, left 8 Footwell module FRM 3 Front fog light, right 9 J unction box control unitj B 4 Main headlight, right KL 30 Kl. 30 Terminal 30 5 Line to ride-height sensors K-CAN K-CAN Body CAN 6 F-CAN connection LIN-Bus LIN-Bus Local interconnect network bus Signals via the F-CAN and K-CAN In/out Information Source/sink Function In Road speed Rotation rate sensor > dynamic stability control Switch on turn-off light (switch on criterion of turn-off light) In Steering angle Steering angle sensor > steering column switch cluster > F-CAN Switch on turn-off light (selection criterion of turn-off light) In Reverse gear engaged Gear selector lever switch > electronic transmission control >PT-CAN >junction box control unit > K-CAN Switch on turn-off light (switch on criterion of turn-off light) In Switch on direction indicator Steering column stalk, direction indicator > steering column switch cluster > F-CAN Switch on turn-off light (selection criterion of turn-off light) The low beam headlight must be switched on by the automatic driving light control function for the turn-off light to be activated. The turnoff light is activated only under the following conditions. 17 E70 Adaptive Headlight System Function matrix for activation of the turn-off light: Driving Direction Condition Side with Activated Turn-Off Light Forward •Speed below 40 km/h •Direction indicator activated Same side as activated direction indicator Forward •Speed below 40 km/h •Direction indicator activated On side in direction of steering lock Reverse •Speed below 40 km/h •Reverse gear activated •Direction indicator activated Same side as activated direction indicator Reverse •Speed below 40 km/h •Reverse gear activated •Steering lock Opposite side in direction of steering lock Reverse •Vehicle speed below 65 km/h •Reverse gear activated Both Sides Note: The turn-off light is no longer switched off if only one signal fails, e.g. due to a defect. A special feature of the turn-off light in the E70 is that it is integrated in the fog light. The fog light with turn-off light function can be recognized from the outside by the fact that the reflector is completely chrome-plated. 18 E70 Adaptive Headlight System Fog Lights Design of Fog Light A special fog light is necessary forthe turn-off light. It contains the reflector for the turn-off light. Index Explanation 1 Turn-Off Light Reflector 2 Fog Light Reflector 3 Fog Light Bulb Turn-Off Light Reflector The light from the fog light bulb reaches the reflec- torforthe turn-off light as soon as the fog light is switched on. The reflector is specially shaped and reflects the light in the turn-off area. Index Explanation 1 Turn-Off Light Reflector 2 Fog Light Reflector 3 Light Path Check Control Message The same check control messages apply as forthe fog lights. 19 E70 Adaptive Headlight System Principles of Operation Headlight Swivel Movement Preconditions forthe adaptive headlight To ensure its operability, the adaptive headlight must be adapted to the vehicle specific data.The vehicle-specific data are located in the footwell module and in the stepper motor controllers. The footwell module contains the data: • Vehicle identification number • Vehicle type The stepper motor controller contains the data for: • Headlight and headlight swivel range • Permitted acceleration and deceleration ramps • Characteristic speed maps • Encoding • Vehicle identification number • Vehicle type Switch-On Conditions The adaptive headlight can be activated as from terminal status "terminal 15 ON". Initially, the footwell module switches on the stepper motor controllers. The adaptive headlight is ready for operation following a reference run of the bi-xenon headlights. Note: A reference run is performed during every new start. The conditions for switching on the adaptive headlight are: • "Terminal 15 ON" • Light switch in automatic driving light control position • Rain/driving lights/solar sensor detects darkness • Both bi-xenon headlights are intact Note: The footwell module detects a defective bi-xenon headlight by measur¬ ing the intake current of the respective bi-xenon headlight. 20 E70 Adaptive Headlight System Switching On Adaptive Headlight The adaptive headlight is switched on as soon as the rain/driving lights/solar sensor sends the switch-on signal forthe low beam headlight. Function Indicator Operation of the adaptive headlight is indicated by permanent activation of the LED for automatic driving light control. However, if the LED forthe automatic driving light control flashes while the adaptive headlight is active, this indicates that there is a fault in the adaptive headlight. The low beam headlight and the headlight vertical aim control remain active in the case of fault. The swivel function of the bi-xenon modules is deactivated. The light switch must be in the automatic driving lights control position. Reference Run In orderto determine the zero position, the adaptive headlight performs a reference run depending on the current position of the swivel module. To avoid a hysteresis during calibration, the swivel module always moves from the same side overthe zero position sensor. This is achieved in that the swivel module is always moved to the same side of the zero position sensor before switching off the adaptive headlight. Zero Position Sensor The zero position of the swivel module with respect to the zero position sensor is detected by a 1/0 edge when swivelling from the direction of the off position in the direction of the optical axis. The swivel module is repeatedly calibrated during opera¬ tion based on this "soft" reference point. 8 Index Explanation Index Explanation 1 Mechanical stop, minimum 6 Electrical stop, maximum 2 Electrical stop 7 M echanical stop 3 OFF position 8 Swivel direction 4 Position of zero position sensor 9 Reference run from left 5 Position of optical axis = 0 21 E70 Adaptive Headlight System Mechanical Stop Items 1 and 7 representthe mechanical stops of the swivel module. The mechanical stops are defined by the design of the headlights. Differential Angle A differential angle is required when the position of the swivel module is not known. A reference run that extends to the mechanical stops must be performed forthis purpose. This is known as a "hard" reference run. Optical Axis The swivel position, in which the swivel module is in the straight-ahead direction of the vehicle is referred to as the optical axis. An angle of 0° is assigned to this position. The optical axis is defined exactly as an angle with respect to the zero position sensor and as an angle with respect to the mechanical stop. Consequently, the optical axis during swivel movement can be "normally" determined by way of the zero position sensor. The differential angle with respect to the mechanical reference point is used in the case of fault. Swivel Range Normally, the swivel module does not extend to the mechanical stop but ratherto the electric minimum and maximum stop. Adjustment of the swivel module to the electrical stops avoids the loss of pulses on reaching a mechanical stop. The minimum and maximum electrical stops are defined as angles with respect to the zero position. The movement range of the headlights is 8° with respect to the vehicle center and 15° to the outside.The swivel range is not restricted by mechanical tolerances. Swivel Direction Driving the stepper motor in positive direction of the swivel module corresponds to swivel movement to the right. Traverse Rate The traverse rate of the swivel modules is up to 30°/s. 22 E70 Adaptive Headlight System Swivelling The following signals are made available to the footwell module forthe purpose of moving the swivel module. • Steering angle • Road speed • Yaw rate Under normal driving conditions, the adaptive headlight is controlled by the data from the steering angle sensor up to a speed of approximately 40 km/h. The yaw rate sensor is included in the calculation: Index Explanation 1 Vehicle Speed 2 Steering Angle 3 Yaw Rate • at speeds higherthan approximately. 40 km/h • in the event of vehicle oversteering or understeering • a vehicle tending to yaw The vehicle oversteering/understeering oryawing is detected by means of the steering angle sensor and the yaw rate sensor. The adaptive headlight is deactivated in the event of the vehicle oversteering/understeer¬ ing oryawing.The swivel module returns to its zero position. 23 E70 Adaptive Headlight System Stepper Motor Controller The stepper motor controller controls and monitors the stepper motors forthe adaptive headlight and the headlight vertical aim control of the respective bi-xenon headlight. The stepper motor controller performs following functions: • Receiving and evaluating the data sent from the footwell module via the LIN-bus: - Reference run - Target position commands - Diagnosis requests • Output control of the stepper motors • Zero position acquisition of swivel module • Reference run of swivel module • Position feedback of swivel module to footwell module • Diagnosis • Feedback of diagnosis data to the footwell module The footwell module in its function as the central control unit forthe adaptive headlight checks the status of the stepper motor controllers every 20 ms. Stepper Motor Controller (g>= =(S) (i) SMC LlN-Bus \ I *0 -0 Index Explanation 1 Stepper motorfor adaptive headlight 2 Stepper motor controller 3 Stepper motor, headlight vertical aim control 4 Zero position sensor 5 LlN-Bus 6 Coding pin for right/left 7 Voltage supply + 24 E70 Adaptive Headlight System Zero Position of Swivel Module The zero position of the swivel module is determined by the zero position sensor. The zero position sensor is a Hall sensor. The falling edge of the Hall sensor is evaluated to determine the zero position.The zero position corresponds to exactly the position ofthe swivel module in the straight-ahead position ofthe vehicle. The stepper motor controller prepares the data for data transfer via the LIN-bus.The footwell module requests the data from the stepper motor controller. Note: The sensorsignal can be read outduring diagnosis.The sensoris defec¬ tive if no sensorsignal is applied. Switch-Off Conditions As from "terminal 15 OFF", the footwell module sends the request via the LIN bus to assume the rest position of both swivel modules to the stepper motor controllers. On reaching the rest position ofthe swivel modules, the stepper motor controllers send an acknowledgement to the footwell module. On receiving the acknowledgement, the footwell module switches off the stepper motor controllers. Afterunning Time The afterunning time is 2 s. 25 E70 Adaptive Headlight System Service Information Replacing Components Various repairs may be necessary during the course of the vehicle's service life. As a consequence of repair work, it is possible that the system components forthe adaptive headlight are installed with different software and hardware versions. New and/or used parts are used together with the components already installed in the vehicle. In each case, the replaced components must be adapted to the specific requirements of the vehicle. The following components can be replaced as part of servicing: • Footwell module • Stepper motor controller • Bi-xenon headlight • Bi-xenon headlight retrofit Footwell Module After replacing an footwell module, it is necessary to enter the vehicle identification num¬ ber and to encode the control unit depending on specific vehicle data. The complete adaptive headlight function will not be operative if adaptation to the vehi¬ cle is not performed. Stepper Motor Controller After replacing the stepper motor controllers, it is necessary to store the vehicle identifi¬ cation number and enter headlight related coding in the stepper motor controllers. The complete adaptive headlight function will not be operative without this adaptation. Particular care must be taken when replacing the stepper motor controllers to ensure that the housing gasket of the stepper motor controller is fitted and seals correctly. Bi-Xenon Headlight After replacing the bi-xenon headlights, headlight-specific encoding is necessary for the respective stepper motor controller. If this adaptation is not performed, the function will appear to be operative but not cor¬ rect. The swivel range and zero point can vary from vehicle model to vehicle model and the bi-xenon headlight can have a different status! The headlights must be adjusted and checked. 26 E70 Adaptive Headlight System Diagnosis Malfunction M alfunctions that may cause the adaptive headlight system to fail are listed in the following: Number Description 1 Step error within the specified tolerance range Yes Self-adjustment every time a level change of the position sensor is detected. 2 Step error outside the specified tolerance range Yes Swivel range mechanically restricted, swivel module is moved to zero position, the swivel function is dis¬ abled, headlight vertical aim control remains active. 3 LIN-bus failure Yes Stepper motor controller: Emergency program. Footwell module: Error signal to indicator lamp, if possible move the stepper motor controller that is still operable in the optical axis position, headlight vertical aim control remains active. 4 UB- orGND and failure for stepper motor controller Yes Stepper motor controller: Operation not possible, system shuts down. There is no emergency power supply. FRM: Error signal to indicator lamp, nevertheless the stepper motor controller that is still operable is moved to the optical axis position and the swivel function is deactivated; headlight vertical aim control remains active. The corresponding headlight is deactivated as required. 5 Position sensor defective Swivel motor defective Turning mechanism defective It is not possible to distinguish between a position sensor defect and a mechanical swivel motor defect. Absence of level change of sensor signal within the specified tolerance range. Stepper motor controller: Emergency shut-down of swivel function. Low beam headlight disabled on affected side if there is a risk of dazzling. Fog lights switched on as substitute function Telegram to footwell module The dazzle effect may be avoided by lowering the headlight range using the vertical aim control. 6 Swivel motor electrically defective, short-circuit or break It is not possible to distinguish between the actual motorfailure and a defect in the supply line. Immediate shut-down of the swivel function. After evaluating the position sensor, in the event of possibly dazzling the oncoming traffic, the headlight range is reduced orthe headlight is switch off via the vertical aim control. 7 M otor for head light vertical aim control electrically defective, short-circuit or break Yes Immediate shut-down of the headlight vertical aim control function. 27 E70 Adaptive Headlight System Diagnosis Mode The adaptive headlight must be set to diagnosis mode for following diagnosis tasks: • Read out of relevant bus signals with vehicle stationary - Road speed - Yaw rate - Steering angle • Checking signal plausibility • Checking that conditions for activation are fulfilled - Rain/driving lights/solar sensor status - Light switch status M issing or non-plausible BUS signals are stored in the form of fault codes in the footwell module. The fault types are stored in the stepper motor controller. The stepper motor controller is accessed via the footwell module. 28 E70 Adaptive Headlight System