Great thread, but cannot find the answer to my particular issue.  The xenon lights on my 09 L&K do not adjust at all, and the garage tells me I need a new offside headlight unit at £435!  I assume there is a mechanical problem within the unit.  Is it possible to dismantle the unit and replace components, or oil the mechanism which might have seized up?

My car has developed very short-sighted xenon lights all of a sudden too. 

 

It went in for it's MOT on Saturday and could it be that, when it was on the ramps, one of the sensors is no longer in the correct position? If so, will I need to take it to the dealer to get it sorted or is it something I could do on the driveway? I don't have anything other than a scissor-jack to help.

This has just happened to me. In my case the arm holding my rear sensor to the left rear axle had broken meaning the sensor reading was out of range. I managed to stick the arm back together and fix it back on and so far it has held. It coincided with being in for some work on a ramp too.

It seems when the suspension returns to standard position the sensor arm can orientate towards the right rear wheel instead of the left wheel. I reckon the garage tried pushing mine back the correct way without lifting it high enough to do so without breaking the arm, but I can't prove it of course.

If it has gone the wrong way it should be possible to reset it correctly by lifting it up high enough. There are some useful pictures (not mine) linked from the thread I started here:

http://www.briskoda.net/forums/topic/332573-xenon-light-issue/#entry4002825

Edit: I swapped left and right above after discovering I got the orientation wrong myself!! Please see later posts.

When the car is on a ramp, especially for an MOT the car is jacked so that the tester can rotate each wheel and check the wheel bearings.

 

This then extends the suspension (and therefore the short arms for the xenon's automatic levelling sensors) to their maximum.

 

Any weakness or wear in the arms means they'll be at their most vulnerable for failure when on the ramps.

 

You can see the xenon sensor arm here (silver). Jack up the car and remove the passenger side front wheel for easy access. There is one fitted to the rear suspension too...

 

 

 

More info here...

 

http://www.briskoda.net/forums/topic/244061-xenon-headlight-misalignment/

Edited 3 November, 201411 yr by silver1011

Can I just clarify that if the arm is in the correct position as per the picture above, then the headlight adjustment should be possible in VCDS via the basic settings?

I noticed tonight that the lights were misaligned, pointing too high, but my sensor is still properly fixed in what I thought was the correct position. The measuring block for the rear sensor in VCDS is again down to an implausible value (12.5%, but occasionally fluctuating to 87.5-87.8% oddly) and there is an error now recorded against the headlight module (55) saying no basic settings. This is exactly the problem I had when the sensor arm was broken so I don't really understand why its continuing to crop up given my fix to the broken arm is holding.

It seems either my sensor might be knackered (although as its reading a value, albeit a wrong one, I doubt that), or I have possibly set my sensor the wrong way round, i.e. toward the one wheel instead of the other?

Can anyone confirm whether the V formed by the sensor arm and the sensor itself should point towards the driver side of a RHD car or the passenger side? I think many of the references I have found relate to LHD cars so its a bit unclear if it should point to the passenger side on my RHD car rather than the driver side (as mine is currently set)???

Thanks

Adam

Can you now adjust the lights using VCDS since you repaired the sensor?

 

If not then my guess would be that the sensor is duff. As I understand it an implausable signal from the sensor prevents any adjustments being made.

Yes thats right it does seem to prevent adjustment. I did manage to carry out the basic settings once but that was when the reading was 87.1% and it was right at the limit of plausibility. I thought it was sorted but on reflection I was just lucky to catch a dodgy reading just in the plausible range..

So I reversed the sensor and its now fine and allows me to set basic settings etc. But even after running the basic settings my lights are misaligned.

I am assuming the muppets at the garage have done some manual adjustments which presumably don't get overriden by the electrical adjustment???

Thanks in advance

Adam

I took mine to the local dealer who kindly plugged it in. Turns out the clowns at the MOT test centre had tried to manually adjust the headlights and as was previously said, to correct them, it needs to be plugged into their kit.

 

Fortunately, I now have xenon lights which light more than the first 5m ahead of the car.

Reckon thats what my muppets have done too...