What Causes the Headlights to Move Up and Down When Starting the Car?
2 Answers
When the headlights move up and down during car startup, this is a normal phenomenon. This action occurs because the vehicle is equipped with an adaptive front lighting system. The adaptive front lighting system performs a self-check every time the car starts to ensure the system functions properly. The adaptive front lighting system is a dynamic lighting system that adjusts the low-beam axis horizontally in coordination with the steering wheel's turning angle and vertically in response to the vehicle's height. In other words, the height of the vehicle's headlights can change according to the vehicle's body height. This prevents the risk of accidents in dark environments due to delayed lighting adjustments when the vehicle's height changes.
I noticed many car enthusiasts have encountered the situation where the headlights move up and down during startup. This is actually the automatic leveling system at work, just like what the technician at the 4S shop mentioned during my maintenance visit last week—the system performs a self-check and adjusts the headlight angle every time you start the car. However, if the movement is excessively frequent or continues after parking, you should be cautious. It could be due to the body height sensor being clogged with mud or the shock absorbers aging, leading to inaccurate readings. The most troublesome issue is a malfunction in the headlight control module, which can cost around a thousand bucks to fix. I recommend cleaning the sensor areas near the wheels during each car wash. If the abnormal movement persists for several days, it’s best to get a professional inspection at a specialized shop as soon as possible.
