3 Series E46 316i (M43TU) SAL
Dazzling of oncoming traffic must be prevented in the event of a system fault.
For this reason, the adaptive headlights function is deactivated as follows:
•
If the stepper motors are still functional, the headlights are returned to the straight-ahead position. The
headlights are no longer moved towards bends in the road.
•
If it is no longer possible for a headlight to be moved back to the straight-ahead position, the headlight is
tilted downwards (by the stepped motors for automatic headlight-range adjustment). This prevents dazzling
of oncoming traffic.
•
If the headlight cannot be tilted downwards, the bi-xenon bulb in this headlight is disabled as follows:
When the vehicle is parked up, the control unit registers sleep mode for the adaptive headlights, as
follows: Standstill and terminal R OFF for several minutes.
The next time the vehicle is restarted, the bi-xenon light of the defective headlight is not switched on.
The front foglights are switched on in order to ensure a minimum level of illumination.
The dipped headlight is not switched off while the vehicle is in motion.
Setting headlights to parked position
When terminal R is switched off, the headlights move to the parked position. The parked position is important
for the headlights' next calibration sequence. From the parked position, the headlights are run through a
calibration sequence in the pre-drive-check. During the calibration sequence, the control unit for adaptive
headlights relearns the straight-ahead position for the headlights.
When the headlights have reached the parked position, the stepper motor controllers SMCs inform the control
unit for adaptive headlights ("verification").
The control unit for adaptive headlights deactivates the stepper motor controllers. The run-down period lasts
approx. 10 seconds.
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.
1.
The ride-height sensors and the brake light switch supply the signals for the automatic headlight-range
adjustment.
2.
The control unit for adaptive headlights computes the vehicle inclination (longitudinally to the roadway)
from the signals.
3.
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.
SBT Adaptive headlights E46/2, E46/C, E53, E83
BMW AG - TIS
19.01.2013 20:58
Issue status (12/2007) Valid only until next DVD is issued
Copyright
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