Hmmm, now that autumn is coming and the nights are drawing in I've noticed that my Xenons are going a bit mental.

Moving in traffic on a flat road and with a car in front I can see the light beam will raise, lower and then recentre (similar to at start up) despite there being no change in gradient. This is happening quite often.

Something is definately up - was reversing the car into the space at home and at one point the beam was quickly jigging up and down like it was having a fit!

I've had a brief search on here and haven't found any info, could there be a simple reason for this fault or is it a back to the dealer job?

Niall

Will need a fault code check, could be one of a few things.

ive noticed it tonight, didnt dare overtake the car in front in case he put his onto full beam. however other nights they can be fine, again on others too low or too high or bounce. i can never guess how they gonna act and nothing comes up on fault code check either.

If all else fails its well worth checking the basic settings as with everything electrical sometimes the learned positions get forgotten.

I'd say do the basic settings procedure that Lummox mentions - Requires VAG-COM or a trip to the dealer.

Tricky problem; a couple of guesses - loose wire, faulty sensor or water in electrics. Either way, as already suggested, VAG COM or dealer diagnostic is likely to be the only way to get an answer.

One possibility though, thinking laterally, as this fault make the car (potentially) undrivable, :eek: you don't really want to drive to your dealer, do you? Why not call out Soda Assistance and see if they will send their friendly RAC man, complete with diagnostic kit! He may get it fixed but if not, might well be able to tell you the problem.

ill get the vag com out shortly for mine. what do i have to do to them again stu?

Courtesy of Ross Tech -

Headlight Adjustment

[select]

[55 - Xenon Range]

[basic Settings - 04]

Group 001

[Go!]

Activate the Basic Setting.

[ON/OFF/Next]

The meas. block field now shows "Wait" and should switch to "Adjust Headlights" then (this may take up to 10 seconds).

Adjust the headlights using their manual adjusting screws as referenced against a suitable aiming target.

[ON/OFF/Next]

The adjustment should now be learned.

[Done, Go Back]

[Close Controller, Go Back - 06]

update, ive done the above and will see tonight if there is any difference, its booked in at the garage soon so they can do the alignment and full check too. just an idea, my driveway is on a very slight slope (thus why i do the setting on the road) the car sits normally on my drive facing down the slope. if i was to park it facing up the slope and did the vagcom thing above would when i am on flatter ground the beam point lower to the ground? or would it just cause more problems?

I'm pretty sure the setup should be done on level ground with the handbrake off.

i know it needs to be done on level ground just wondering if the car was facing up a hill and calibrated would it mean on the flat it would point lower down? its just an idea that is running through my head on this calibration set up.

i did an advance measurement tonight as the calibration wotsit above made them really bounce and shine to the sky at times p-----g off lorry drivers as well as car. but then 5 mins from home the settled down for a few minutes. anyway i run the advance measurement and got this:

Thursday,04,September,2008,01:07:17:61864

VCDS Version: Release 805.1

Data version: 20080823

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

01:06:59

27.5 % Front Sensor (G78) (actual)

72.2 % Rear Sensor (G76) (actual)

27.8 % Front Sensor (G78) (learned)

72.5 % Rear Sensor (G76) (learned)

the front should according to vag com be closer to 12% and the back 50% or something? my figures above to what vagcom recommends are totally out. have checked its set up to a 1Z front wheel drive skoda. dont know what the importer codes should be etc but havent been touched by me.

looking at the full beam tonight that looks high too so im guessing it might be a case that the alignment is way out and probably was never touched on PDI.

looking at the full beam tonight that looks high too so im guessing it might be a case that the alignment is way out and probably was never touched on PDI.

Now that you have your 'dip' beam set; best way to get main beam adjusted is to park facing a wall about 10m back. Put your lights on and then see where the main beam falls relative to the dip.

Main beam has manual adjustment screws on the back of the lamp and adjust accordingly.

I have set my main beam so that the centre of the beam pattern nestles slightly above and to the right within the V of the dip beam (if that makes sense).

Paul

I've had a quick look at mine for comparison. Remembering mine is on Eibach Springs and I wasn't parked perfectly level.

cheers stu, ill just wait now till the garage get back to me about booking it in and get them to do it all, then maybe ill be happier with the lights.

well update, tonight after doing this on a drive way facing up a slope last night (flat road seemed to make no difference) i was able to drive home with the beam looking lower to the road, still bounced abit but its booked into the garage in a weeks time for the service and full xenon check and alignment as ive told them im extremely unhappy with the xenons to the stage i will rip them out and install standard lights. so they know how serious i am now about it.

i will rip them out and install standard lights. so they know how serious i am now about it.

Not quite that simple mate.

........ still bounced a bit but .............

Be careful! I thought my Xenons 'bounced' when I first got my car until I understood their workings.

They are not 'Active' to provide a level beam at all times and over all bumps; that would require much more sophisticated levelling sensors than we have and much faster reacting motors on the beam adjustment.

They are merely 'self-levelling' to keep them level with changes of load i.e. full boot of cement bags, and with the (relatively) slow change in attitude of the car under braking and acceleration i.e. the nose dipping and rising.

As Xenons are much brighter and have a more clearly defined cut-off to the beam than regular halogen lamps, you notice any movement of the beam on the road much more particularly with the pitching of the car over bumps etc.

Two acid tests I would like to suggest;

1. Find an unlit, smooth and level piece of road (rare in this country I know) - drive along at a reasonable speed, does the beam pattern move or 'bounce'?

2. Find a straight, unlit road (preferably smooth) with no traffic around (I used the end of a cul-de-sac with a hedge at the end) drive at a reasonable and safe speed, watch the beam pattern on the road and brake hard. The nose of your car will dip but the part of the road illuminated by the beam pattern will not change, as the lights move up to compensate for the nose of the car going down; as you release the brakes and the nose of the car rises, the beam pattern will lower to bring it back level.

I hope that helps.

My car is into the dealers this afternoon to get checked out. I think a sensor might be screwy. Was through in Glasgow last night so had the first good night run in about 6 months.

The levels are off, on smooth motorway the beam is sitting higher than normal, but consistently at that height, so I was getting flashed occaisionally by oncoming lorries.

The fun started when I hit rougher tarmac with a lot of patches on it. The car was obviously transmitting vibrations from the poor road surface but was staying level (as you'd expect). The headlights didn't know where to look! One minute right down in front of the car, the next up in the sky, a wiggle of indecision somewhere in the middle and then back to the slightly too high setting....

Hooray for the warranty!!

Niall

Edited 5 September, 200817 yr by Niall
Spelling

My car is into the dealers this afternoon to get checked out. I think a sensor might be screwy. Was through in Glasgow last night so had the first good night run in about 6 months.

The levels are off, on smooth motorway the beam is sitting higher than normal, but consistently at that height, so I was getting flashed occaisionally by oncoming lorries.

The fun started when I hit rougher tarmac with a lot of patches on it. The car was obviously transmitting vibrations from the poor road surface but was staying level (as you'd expect). The headlights didn't know where to look! One minute right down in front of the car, the next up in the sky, a wiggle of indecision somewhere in the middle and then back to the slightly too high setting....

Hooray for the warranty!!

Niall

I think it would be fair to say; Houston we have a problem! :eek:

PS> but surely on your Pegasus wings (wheels) your car should ride like its on a magic carpet.

well after driving home tonight i can confirm the beam is lower and the road seems abit more lit in front of me and i can now see the beam hitting a point ahead of me instead of it pointing up to the sky. so it must be a sensor misalignment problem as i did the calibration this time sat slightly on a slope (facing up it) and pretended we were on flat ground and now the beam is where it should be, just glad i thought of that idea when i calibrated them, still will get them done at the garage next weekend

Hmmmm, Nearly there......

Went to the dealer on Friday and was surprised to be handed back the keys within 20 minutes.

"It's all fixed"

"Really"

"Yep, he reset it with the computer"

"Reset it, was that all it needed"

"Yep"

"OK then"

Sure enough the Xenon beam no longer scans the skys over rough road surfaces. Unfortunately though the beam now points pretty much down at the ground and doesn't provide usable light more than 4ft in front of the car.

Back to the dealer on Wednesday......

Niall

glad they got it sorted. mine will be looked at this weekend on its service, but i think now ive solved it too.

Right, lets see if I understand this correctly .....

The height of the Xenons is adjusted electronically rather than mechanically, yes?

Mine are too low and I have asked the dealers to look at it but, as the problem only shows up during the hours of darkness, I suspect I may need to learn how to do this adjustment myself.

Where EXACTLY can I find out how to do this adjustment?

Right, lets see if I understand this correctly .....

The height of the Xenons is adjusted electronically rather than mechanically, yes?

Mine are too low and I have asked the dealers to look at it but, as the problem only shows up during the hours of darkness, I suspect I may need to learn how to do this adjustment myself.

Where EXACTLY can I find out how to do this adjustment?

Attention, I've adjusted my Xenons manualy. There are adjusters on each beam.