System Activation and Automatic Calibration
When terminal 15 is switched ON, the headlights always perform a calibration sequence, even if the dipped headlights are not switched on. The control unit for adaptive headlights sends the "perform calibration sequence" request to the stepper motor controllers (SMCs, control units for the headlight stepper motors). The stepper motor controllers actuate the stepper motors in the headlights. The calibration sequence is performed. In the calibration sequence, the headlights move as follows
- The headlights move to the right and left (= calibration sequence for adaptive headlights).
- The headlights move up and down (= calibration sequence for automatic headlight - range adjustment).
- At the end of the calibration sequence, the headlights are in the straight-ahead position.
Following the calibration sequence, the system is ready for operation.
When reverse gear is engaged, the headlights are moved to the straight-ahead position.
Note. The calibration sequence is performed only after terminal 15 has been switched OFF for at least 15 seconds. > E66, E61, E63, E64, E65, E66 until 09/2006 > E87, E90, E91, E92, E93 until 03/2007 If terminal 15 is repeatedly switched on and off (e.g. for demonstration purposes), the calibration sequence will not be executed every time terminal 15 is switched on. Terminal 15 must have been switched off for at least 15 seconds before it is switched on again. Only then is a calibration sequence performed when terminal 15 is switched on.
Note. Calibration sequence always after terminal 15 ON and dipped - beam headlights ON. > E66, E61, E63, E64, E65, E66 from 09/2006 > E70 from start of series production > E81, E87, E90, E91, E92, E93 from 03/2007 If terminal 15 is repeatedly switched on and off (e.g. for demonstration purposes), the calibration sequence will not be executed every time terminal 15 and the dipped-bead headlights are switched ON.
Note. Calibration sequence with enlarged range of movement. > not E65, E66 From 09/2007, starting with the E60, E61, E63, E64, a calibration sequence with larger range of movement will be introduced. The calibration sequence with larger range of movement will then gradually be introduced on other model series.
Adjustment of Headlight Horizontal Aim
The stepper motor controllers move the headlights to the right or left when the vehicle corners.
Horizontal range of movement of headlights
- Inwards, i.e. towards center of vehicle: up to max. 8°
- Outwards: up to max. 15°
Example: Right - hand bend
The right-hand headlight turns by up to 15° (the right-hand headlight is the "inside" headlight on a right-hand bend).
Viewed from the vehicle, the right-hand headlight moves "outwards".
The left-hand headlight moves up to 8° (the left-hand headlight moves towards the middle of the vehicle, i.e. "inwards" as viewed from the vehicle).
The headlight on the outside of the bend has to reach its end position at the same time as the headlight on the inside of the bend so that the carriage way remains smoothly and evenly illuminated.
On a right-hand bend, the left-hand headlight is on the outside of the bend. The right-hand headlight is on the inside of the bend.
Automatic Headlight-Range Adjustment
If the special equipment "Adaptive headlights" is fitted, the control unit for adaptive headlights also controls the automatic headlight-range adjustment.
The automatic headlight - range adjustment adapts the headlight range for different operating conditions. Variations in the vehicle tilt angle are produced by vehicle loads and braking or acceleration in extreme driving situations. The automatic headlight-range adjustment moves the headlights up and down as required.
The control unit for adaptive headlights also controls the automatic headlight-range adjustment as follows
- The ride-height sensors and the brake light switch supply the signals for the automatic headlight-range adjustment.
- The control unit for adaptive headlights computes the vehicle inclination (longitudinally to the roadway) from the signals.
- The stepper motors for the automatic headlight-range adjustment automatically and dynamically control the headlight range. The headlight range is adjusted so that the actual headlight range conforms to the legally required headlight range as follows: If vehicle rear is lower than front: The actual headlight range will be longer than the legally stipulated range. The headlight beam height is lowered to reduce the headlight range to match the legal requirement. If the vehicle is horizontal: The actual headlight range will be the same as the legally stipulated range. If vehicle front is lower than rear: The actual headlight range will be shorter than the legally stipulated range. The headlight beam height is raised to increase the headlight range to match the legal requirement.
Automatic Alignment Of The Main-Beam Assistant
In order to operate correctly, the image sensor must be aligned parallel with the vehicle's centerline. When the car is driven at night, the main - beam assistant can automatically correct alignment up to 3° to the left or 3° to the right. This correction compensates for minor deviations from the centerline.
Driving conditions for automatic directional orientation of the main - beam assistant are
- Straight ahead for a distance of approx. 50 km: A relatively straight stretch accelerates the directional orientation.
- Road marking must be clearly visible.
See IMAGE SENSOR FOR THE MAIN-BEAM ASSISTANT: E60, E61, E63, E64, E65, E66