By YOUCANIC on Jan 18, 2019
In this guide, we take a look at common problems that trigger BMW adaptive headlight dashboard warnings and malfunctions. This guide is meant to help BMW owners to troubleshoot BMW adaptive headlamp problems.
BMW adaptive headlights problems can cost anywhere from $600 up to $1500 to repair at the shop. This guide will help you better understand some of the common issues and possible problems that you can fix yourself.
This is a list of possible errors and symptoms that you may see when BMW adaptive headlights fail.
Located right under each headlight housing is the adaptive headlight module which often is the culprit. It may also be refered to as the Stepper Motor Controler (SMC) or ALC Adaptive Headlight Drive Control Unit Lighting Module. This is referred to as the Stepper Motor Controller - SMC. The controller often fails after heavy rain or if you recently went through a car wash.
The main reasons why the adaptive module fails is because water shortens the module. A cracked headlight or a loose access door in the back of the headlight will allow water to enter the headlight. Because the SMC is at the lowest point of the headlight, water gets to the module and damages it triggering the Adaptive Malfunction error message on dashboard.
If that's the case, you will have a fault code stored in the AHL module.
To replace the headlight stepper motor controller you will need to remove the front bumper and the headlight. The module can then be replaced with a used BMW Headlight Adaptive Module. A software such as NCS Expert can be used to code the AHL module to the vehicle.
The motors that physically turns the low/high beam projector can break. The stepper motor is located inside the headlight. It is controlled by the stepper controller module located below the headlight. The motor itself can fail or the link to the low beam projector can fail.
Repair kits for BMW stepper motor are sold online if you are looking to fix this problem without having the replace the headlight. Note that the headlight will need to be removed from the car to fix repair the stepper motor.
The access door behind the headlight has a seal. When you change a headlight bulb you need to ensure the seal is seated properly. If not, it will allow water to enter the headlight and damage the adaptive headlight module.
Inspect the back headlight cover if you are noticing condensation inside the headlight. If water is present inside the headlight, remove the headlight. Remove the stepper motor controller and allow it to dry for at least 24 hours. Install the headlight and make sure the headlight is airtight.
BMW AHL module will need to be replaced and coded to the vehicle.
You will need a diagnostic scanner that is BMW specific and can read all systems. Your scanner will need to read fault codes from the Adaptive Headlight module.
Generic OBD2 scanners won't help. You will need a scanner such as Foxwell for BMW, Autel MaxiDAS, INAP or Launch All System. You can learn more about BMW OBD2 scanners in this article.
Even though we would not recommend deleting BMW adaptive headlights, we have seen many BMW owners go this route. To delete BMW adaptive headlights, you need to code the vehicle with NCS Expert and configure it to think that adaptive headlights are not installed.
When this is done, the adaptive headlights functions are disabled, the low beam lights no longer move, adaptive high beams no longer turn on automatically. Your headlights will function the same as in cars without the adaptive headlight.
Physically removing the adaptive headlight module does not delete BMW adaptive headlights.
Removing the module without coding the car, will result in an adaptive headlight error on the dashboard.
BMW adaptive headlights actively move the headlight projector left and right to illuminate the part of the road the driver is turning.
In cars with BMW adaptive LED headlights, the headlights change the light output according to the incoming traffic. A light camera at the top of the windshield senses the light of the vehicles approaching.
Adaptive headlights also switch the high beams on and off depending on the traffic. When following a car, adaptive headlights will adjust the high beams by moving the high beams outwards which reduces the light in the center. BMW adaptive headlights will also turn off the left high beam when a vehicle is detected on the incoming traffic lane.
In vehicles with xenon adaptive headlights, the fog lights will be turned on at slow speeds when turning left and right. The first generation of BMW adaptive headlights used xenon bulbs while the newer BMWs use LED adaptive headlights.
There is a couple of ways to determine if a BMW has adaptive headlights. One method is to park the vehicle but keep it running. You can look at the low beam move and right as a friend turns the steering left and right.
If the low beam projector moves, your BMW has adaptive headlights. If it doesn't, your BMW does not adaptive headlights. The other method to verify if a BMW has adaptive headlights is to decode the VIN and see if the car has the option for Dynamic Xenon, Adaptive Headlights or Adaptive LED headlights.
Adaptive headlights are disabled when turning the light switch manually to on position. To keep the adaptive lights enabled turn the light switch to Auto.