List Of Malfunctions For Adaptive Headlights

WARNING: This page does not describe the selected car, but rather 37 other vehicles, including the 2006 BMW 330Ci, 2006 BMW 325Ci, 2005 BMW M3, 2005 BMW 330xi, and 2005 BMW 330i. However, it is still accessible from the selected car via links, so may be relevant.

LIST OF MALFUNCTIONS FOR ADAPTIVE HEADLIGHTS

Faults	Description
1	Stepping error within specified tolerance range: The swivel module aligns itself (each time a change in pitch of the zero-position sensor is detected).
2	Stepping error outside specified tolerance range: Range of movement is mechanically restricted. The AHL control unit and the stepper motor controller respond as follows: At first, an attempt is made to "compensate" for the difference between actual and nominal values by generating a number of turning movements. Each turning movement compensates for "lost" steps. If an adjustment is not possible because the swivel module is "sticking", an attempt is made to move the headlight to the straight-ahead position (= 0 degrees). The turning movement of the adaptive headlights is deactivated. Automatic headlight-range adjustment (LWR) remains active.
3	If the LIN bus (local bus, Local Interconnect Network) should fail, the AHL control unit and the stepper motor controller respond as follows: Stepper motor controller (SMC): emergency program: if the stepper motor controller (SMC) is still responding, the swivel module is moved to the straight-ahead position (= 0°) Fault message to the indicator light on the light switch cluster Automatic headlight-range adjustment (LWR) remains active.
4	Missing earth connection or earth fault in stepper motor controller (SMC): The stepper motor controller (SMC) is inoperable. There is no backup provision. The stepper motors cannot be actuated. The AHL control unit responds as follows: Fault message to the indicator light on the light switch cluster. If the headlight's last position could dazzle on-coming traffic, the bi-xenon light is switched off the next time the system is started. Conditions required for switch-off: The vehicle is parked. It is in sleep mode. Terminal 15 is switched on again.
5	Zero-position sensor or position sensor defective or headlight motor defective or headlight mechanics defective: No distinction can be made between a defect in the zero-position sensor (or position sensor) and a mechanical defect in the headlight motor. If no change in pitch of the zero-position sensor (or PWM signal from the position sensor) can be detected within the specified tolerance range, the AHL control unit will initiate the following function limitations: Stepper motor controller (SMC): Emergency deactivation of the swivel movement Safety: prevents dazzle by lowering the automatic headlight-range adjustment or switches off bi-xenon headlight on the side affected (only when the vehicle is parked and after sleep mode has been reactivated) Message to light switch cluster Switches on substitute function (fog lights)
6	Electrical fault in headlight motor (short or open circuit): no difference between failure of electric motor and fault in wiring; the stepper motor controller (SMC) responds as follows: Emergency deactivation of the swivel movement If the oncoming traffic may be dazzled (signal analysis by the position sensor or zero-position sensor), the headlight is angled downwards. The headlights are angled downwards by the headlight-range adjustment motor. If the headlight cannot be moved down, the bi-xenon bulb of that headlight is switched off. Conditions for switching off: the vehicle must be parked (and terminal R must be OFF for several seconds).
7	Electric defect in automatic headlight-range adjustment motor (short or open circuit): automatic headlight-range adjustment is deactivated.