bnz616

I have a 2002 with OEM xenon. Just got my car back from service. One of the things it was in for was the creaking front. For the front creaking, they replaced the bushings on the front lower control arm.

I drove the car tonight and noticed that the headlights are aiming too low. I'm sure they haven't touched the headlights themselves. I read from another post that the sensor is located on the sway bar. They might have moved the sensor? I set the lights to AUTO and started the car to allow the headlights to level. Instead of going way up, then going back down to the proper level, it goes down a little bit and then goes back up. I know that before, it used to move up quite a lot. Now, it barely moves, and instead moves down then up.

I want to see if this problem can be solved without taking it in to the dealer. It has just been in there for a week and I just got it back today.

Attached are some pictures below. They were taken from a view facing the passenger side front wheel well.

Is the circled part in this picture the auto level sensor? Is the sensor installed correctly?










Rear auto level sensor?

rrf

They rotated the front sensor incorrectly when they reinstalled the new bushings. Should be like \ vs. like this /.

Rear should be AOK since they didn't work there; and the front threads show that it was never actually removed, but was re-positioned incorrectly.

You can just loosen the arm-end-bolt, and pivot and reattach it on the other side.

Here is a pic. You can see the arm-end-bolt on my pic and not yours.

bnz616

Is your car also a 2002 with the OEM regular xenons (non-bixenon)?

miroj

I think the pic explains it all. A quick scan with the diagnostic would have revealed the angle of attack in the sender arm that signals the level. With diagnostic it comes up as a reading outside the allowed limits.

As stated, the arm is rotated to the incorrect angle.

bnz616

Cool, thanks guys. The lights are pointing way too low, its actually dangerous to drive at night, can't see very far in front of me.

So by rotating the arm to the other side, so it is like ">" instead of now "<", my headlights should level normally and point higher to the right height.

Should I just remove the U bracket from the bottom plate and just stretch the arm out and pivot it over? I see bolts at the joints, but I thought the joints are held together by ball pivots, would taking it apart there have a chance or screwing up the joints.




I also posted this on the W203 c-class section and got a reply with two others who experienced the problem after having their control arm bushings done/worked on. It seems as if the sensor has to be reset or recalibrated? Maybe I need to correct the sensor arms and then have it reset? Or maybe the sensor position was never corrected and then recalibrated/reset according to the current position of the sensor.

There was actually a diagram in another thread, exactly like you have yours, rrf.

rrf

DO NOT remove the bottom unless you must, [if you did you would need to 'recalibrate the system'. It can be done but why bother].

Do this instead>>
"You can just loosen the arm-end-bolt, and pivot and reattach it on the other side." You are going to luck out on this one.

Try doing it at #8 if you can, if not there then at #2,
if not at #2, THEN loosen the u-clamps. But if you loosen the U-clamps you need to try to the bracket on exactly as it came off.

Calibration will most likely take care of itself, if you do the #8 or #2 thing. If it doesn't then you can move and rotate the sensor assembly to get the vertical position close and then use the screws on the lights to tune it further.

bnz616

Doh! I actually moved the bracket a little bit yesterday to check to see if it was in the right place.

I tried to reinstall it as close as possible to the way it was, based on the pics I took. Is it very sensitive to how closely it matches up with where it was? If I am a little bit off, will it throw the height of the leveling off. It won't cause one headlight to point higher than the other will it. The sensor just simply reads differences in front and rear along a straight line and not side to side or diagonal tilt right?

rrf

All's OK, and what's done is done.
Now if you are "close" you can choose to either level the lights via 1) the typical two headlamp adjustment screw assemblies or 2) wiggle/try/repeat on the sensor.

If you are "far" off then you must get the sensor "close" first before you adjust the headlamp screws. A couple of guys over adjusted the screws and the lamps became "off-track".


Yes, for you both lights will be level and off the same amount.

bnz616

Okay, I will give that a try. I think the sensor should be pretty close, maybe 1 mm off. If the sensor reads very fine measurements, then it might be a little off.

I guess if it is just a little bit off, it should be fine as long as both headlights are level and are off together.

I assume when the arm "\" is swung further to the right, the sensor will read that the car is lower and will actually point the headlight higher. So if my bracket is a little more to the right than it was before, the headlights will actually point higher than they should be pointing.

Thanks a lot for the help.

x-tian-230k

Is it me or is it in the last picture the exhaust pipe seems to be glowing Orange???

bnz616

Haha it's actually a flashlight. The camera was having trouble focusing in the dark. Had to light up something for it to focus on. =)

bnz616

I decided to take it to the dealer this morning to get it all done by them because I was thinking I need to get the sensor recalibrated anyway since I moved it, so might as well not go through the trouble of moving the sensor over. Basically the work they did was "headlamps adjusted". The sensor is still sitting the same "<". I don't think they touched it. It is the right height now, it starts low, then levels up to the right height...does that sound right? I seem to think that it used to move up, then down to the right height.

The height is right now which is cool....but I'm still wondering if the sensor is working properly the way its positioned, or if it even matters which way it is.