[fridd75]

Hello all, I recently joined the forums, but have been hanging around for sometime. I am a proud and happy owner of a Titanium Silver MY07 328i. I have had this car for a couple of years and I still never get tired of her! Recently though I've run into a crazy problem with my auto-leveling headlights (non-AHL). The car has been behaving fine until about 2 weeks ago. It has always been doing its self-check on startup, turning the light down towards the ground and then turning back up again. Then one day, upon starting the car, I noticed that it didn't go through the self-check anymore, but instead would 'jerk/twitch' about its current position. You can hear the motor 'buzzing', but the light beam would merely jerk or twitch somewhat and then stay put. The weird thing is, this doesn't happen all the time. It seems to be an intermittent problem. At times it goes through the entire self-check as normal, but at other times it doesn't. Sorry for the long post, but I wanted to be as detailed as possible. Here's what I've observed:


1) Sometimes, the lights would run through their normal self-check, with the lights sweeping down and then back up again. Sometimes, the lights merely jerk/twitch about their 'central' position and don't run through the self-check/don't correctly aim itself. By 'central' I mean the position the lights were at when I last shut off the car.

2) At times, the lights will jerk/twitch about its central position and then point into the sky. At other times, the lights will jerk/twitch about its central position and then point into the ground. And, at other times, the lights will jerk/twitch about its central position and then stay put. In all cases, you can still hear the motor, like as if its trying to move but cannot. I have to restart the car anywhere from one to a few times, depending on the car's mood, before I can get it to properly run through the self-check and correctly aim itself.

3) Both headlights either do the normal self-check in sync, or jerk/twitch in sync. In other words, both lights do the same thing, they either both work or both not work. This seems to suggest that it may not be a fault with the individual leveling motors within each headlight.

4) The number of occurrences of the jerk/twitch scenario is higher if I start the car into ACC first, and then start the engine afterward. In this scenario, the lights usually jerk/twitch instead of run through the self-check. If I immediately start the engine with foot on brake, the car usually runs through its self-check as per normal. I say 'usually', since the occurrence of the jerk/twitch isn't completely eliminated in this case, it just happens less frequently.

5) Regardless of whether the self-check is completed properly or the lights jerk/twitch on startup, I don't notice any jerking or twitching of the light beam after the startup phase. The light beams are rock steady in either scenario.

6) After I lock the car, but before the car goes to sleep, I can sporadically hear the leveling motors in the headlights trigger for a split second. This happens a couple of times each minute until the car goes to sleep. I don't know how to describe the sound, but it's like a 'muted clicking' or 'thudding' that happens for a split-second, for a couple times every minute. The car is physically not moving or changing in ride height. It's almost as if the FRM is still sending a signal to the leveling motors. Once the car sleeps, it seems to stop happening.


I've visually inspected my front and rear level sensors, and both look like they are still physically connected to the suspension control arms, with no broken bits. I've searched around and know that some others have had their leveling gone rogue due to broken leveling sensor arms. In my case though, the sensor arms look to be in good shape. I don't think the ball joint inside the headlights (the one that attaches the leveling motors to the internal housing) has come loose either, since the lights still do perform the normal self-check from time to time, whenever it feels like it.

Could this be a faulty leveling sensor nonetheless? Or worse, a bad FRM? I'm hoping it's not the latter. It seems like it's still able to run through its self-check from time to time, so perhaps it's not the FRM (at least I want to believe that it's not!). From an electrical circuit standpoint, I'm wondering if one of the sensors may be faulty and occasionally sending incorrect voltages to the FRM, and the FRM is just sending signals to the leveling motors based on what it has been told by the sensors.

Folks, I am completely stumped by what's going on... can anybody chime in on this? Please help...

[fridd75]

Hmm, not sure what you mean... but I actually really am experiencing this problem, which is why I spent all that time typing it up so I could get some help from around here...

[Das_Stig]

happened to me with one of my headlights in oct. got it changed under warranty. :l
they tried to tell me it didn't need to auto adjust because it was already aligned at first.. thats perillo for you..

[fridd75]

Das_Stig, thanks for sharing, did they say which component was at fault? It seems like a pretty big measure for them to replace the entire headlight if it was only a leveling motor causing the problem. In my case, the same effect is simultaneously happening with both headlights, they either both auto-level or both not auto-level. That kinda led me to think the motors were fine and were just doing what they were being 'told' to do by the FRM, which is in turn getting it's signals from the front and rear level sensors.

Anyone else with similar experiences?