porschefan1013

Or at least I assume they're not working...

When I first drove the car at night, I noticed that the headlights were aimed very low. It was my understanding that when you turn on the headlights, they should do a little up/down dance, ultimately settling at the correct level. Is that correct?

This didn't happen. So I took my car to the dealer to have it looked at. $125 later, they told me that the sensor on the front passenger side was not returning the proper level of voltage and that I needed to have the sensor replaced.

Well I came home, not eager to spend another $250+ and just adjusted the damn things using the manual screws. Now my headlights are at the proper level. Sometimes I will see a VERY slight movement, but nothing major. Again, is this normal?

Thanks,
Matt

p.s. I tried unplugging the sensor (behind the wheel) as well as disconnecting the battery to reset things. No dice.

porschefan1013

I guess the cliffs for all of that...

1) How much movement should I observe when turning on my headlights?

2) Will this sensor replacement more than likely fix it, if there is in fact something abnormal going on here?

pointman

Yes. But only if you have them set to auto, or turn them on fast after starting the car.

My movement is significant.

Had same issue. Dealer tech turned the sensor over after doing some work. Another tech flipped it over, and all was good.

lkfoster

Same thing happened to me after a visit to the dealer. Headlights were looking for earthworms.

03MBC32

I also had the same situation after some dealer front end work some time ago. Unfortunately my sensor just went bad and will need to be replaced as the light are pointing down..

Dingleberry

https://mbworld.org/forums/c-class-w...-distance.html

porschefan1013

Thanks man...much appreciated!

Between that and another thread (proof that "search" does work):

https://mbworld.org/forums/c32-amg-c...-properly.html

I think I've corrected the issue. My sensor was improperly positioned....I loosened up the bracket attached to the swaybar and pivoted it to the proper position.

Maybe me previously adjusting them upward (manually) had something to do with it too. Whatever the case, they do a little dip down and then come back to the proper height.

MACHC5

When I had some suspension work done on my C55 the headlights started looking at the ground. A trip back to the dealer and all was well. The sensor has a lever that connects to the sway bar and was needing adjustment. It looked like something that was designed by Rube Goldberg.

porschefan1013

That's funny! Not unusual for a Mercedes Benz part....more complicated than it needs to be.

Mark.D

Matt - So are you servicing your car in Cool Springs? Thats a beautiful dealership. I test drove a 911 C4S they had in inventory about a year ago.

porschefan1013

Mark, that's Mercedes Benz of Nashville, located in middle TN...I'm on the west end of the state, so I go through Mercedes Benz of Memphis.

You're right though...it is a nice dealership, as well as the closest authorized Kleemann dealer. TN is fortunate to have 3 very nice Mercedes stores (Memphis, Nashville and Knoxville)...each one is unique. I suppose that's where your money goes.

Also, love me some C4S!! 996 or 997?

pointman

You're welcome.

CFiftyFive

My C55 bi-xenons bob down then up when starting up the car, but my concern is that the passenger side has more motion than the driver's. Drive side only goes down and up around 2 inches while the passenger's move around 4 inches or so. Is this normal?

I also measured the headlight throw on the road and the driver side cut off goes to about 60-70ft away. Is this okay or too low?

CFiftyFive

Anybody? Any C55 bix owner who knows?

lkfoster

I would guess, and it's only a guess without looking at the manual, that your DS light is out of adjustment. Either the control module thinks that the light is not where it's at or the manual adjustment is off, either way when cycling to the full dip position the DS light is hitting it's full depression stop too soon.

There is a procedure for zeroing the lights but I think that you need a STAR machine to do it. I know that I can do it with a laptop on my Audi, but MB isn't quite so tolerant of the aftermarket.

I would try manually adjusting the DS light against a wall to match the passenger side to see it that fixes both problems.

CFiftyFive

By using the adjustment screws on the headlight housing?

lkfoster

That's what I would try, just do it gradually and watch which way the beam moves to make sure you're going the right way. And remember how much you've moved things so you can go back if you need to.

CFiftyFive

Hmmm, so manually adjusting it via the screws and setting it to the right height will ultimately fix the "limited range of motion issue" I have with the auto levelling mechanism?

lkfoster

It could be part of it, but unless you have a STAR machine it's the only choice that you have. I'm more inclined to think that a position sensor is off, but that's within the STAR realm. There's nothing to lose by trying as long as you watch what you're doing. At the very least you'll get the range right.

ghiaguy

Sorry to resurrect this thread, but I just had the upper control arms replaced on the C55 and my headlights are shooting basically straight down now. Is there a level sensor up front that was likely reinstalled incorrectly or something? How did you guys solve this one?

lkfoster

When I had some work done once at the dealer they installed the front level control sensor arm upside down (or so they said). The result was the same thing as you have, the lights looked for earth worms.

If the system is the way that I remember there are sensors clipped to the front and rear sway bars. Look for the sensor and where it connects to the front sway bar. First thing is to make sure that it's connected. If that's OK, by playing around with the connection between the arm and the sway bar you should be able to get the lights back to where they should be.

ghiaguy

Great, thanks. I will take a look to confirm the elbow on that front sensor is facing the right direction and check all fittings. Seems like a stupid problem that could have been solved at the design stage..

betrezra

If you have access to STAR you can read the voltage signal from the sway bar h/l level sensor real-time as you manipulate the lever. GL.

maverik259

Ya i had my alignment done about 2 months back and they replaced my bolts with adjustable camber ones and i didnt find out till 2 days later when they came on at night and pointed straight at the deck! took it back to them and was like umm WTF...of course they couldn't possibly have done it until the tech came back and was like the sensor was out of position...hmm funny how they were just fine until you dorks got under there! and you'd think they'd notice except they turn off the auto head lights switch and never turn it back on when finishing the work...

ghiaguy

Called my tech since this all came about after my upper control arms were done last week. He said he will look at it and reset through STAR. I hope this does the trick- he said they wouldn't have had to mess with the sensor to do the control arm job, but I know it was just fine before they serviced the car...