This month – I’m explaining BMW adaptive headlight technology. This technology has actually been around since the early 2000’s and is an option you may be unaware your vehicle has, if equipped.
Adaptive headlights are low beam / high beam headlights that actually turn left to right with your steering input as you drive. This early illumination around corners during night time driving can be the difference between seeing an object in enough time to react.
Here’s how the system works:
Each headlight actually has a small electric motor built in behind it that literally moves the bulb housing left to right. The motor is controlled by the Lamp Control Module (LCM) or Adaptive Headlight Control (AHL) Unit. The LCM receives two primary signals from other control units in the vehicle – vehicle speed and steering angle. These two signals are processed by the LCM and the LCM in turn activates the headlight motors left or right at a variable rate of speed based on how fast the vehicle is driving and how far & how quickly the steering wheel is turned.
Adaptive headlights are on autopilot all the time. However, the headlight switch must be all the way to the left in the “A” or automatic position. To check if your vehicle has adaptive headlights, put your headlight switch in the “A” position when it is dark enough outside for the headlights to come on automatically and turn your steering wheel lock to lock while observing the headlight projection against the wall – you will be able to see the light shifting slightly corresponding to the direction of the wheel. Imagine a flashlight whose light is bent. This is a very accurate representation of what this looks like if you turn your wheel more sharply at parking lot speeds. Try it!