Whats up with my headlamps?

[Birdman]

What exactly is meant by self-levelling? It can't mean in relation to the true horizontal so is it in relation to the normal suspension position? In which case, they could be well out of alignment even when self-levelling. Like mine are.
And why the wash-wipe regulation? Does surface dirt scatter the light, or just dim it??

 

[A-AvantGarde]

Guess no Xenons then - i thought that the glass dome lenses indicated xenons - clearly not.

How come behind the headlamd cover it says 'Danger High Voltage' if they are normal halogens?

Cheers.

The domed headlights behind the perspex covers are a feature of the facelift model (2001 +). You may be able to notice this from the picture of my Dad's ML in my signature (his are standard halogen too)

As stated Xenons would have headlamp washers and also light up in an extremely distinctive manner.

 

[freddiea]

That caption seems to have done it for you Mr Toad!

I will seek information on how to switch them and take it from there.

 

[Dieselman]

What exactly is meant by self-levelling? It can't mean in relation to the true horizontal so is it in relation to the normal suspension position? In which case, they could be well out of alignment even when self-levelling. Like mine are.
And why the wash-wipe regulation? Does surface dirt scatter the light, or just dim it??

The self levelling keeps the headlamps level with the road in relation to the position of the car. In otherwords at the cars normal ride height. If a load is placed in the car the headlamps will automatically dip so as not to dazzle other drivers.

The dirt will cause scatter.

 

[Dieselman]

You can't just swap the headlights for xenons, you will need the self levelling system as well and will probably need the option programming into the ECU to make it work.
The self levelling is a legal requirement.

 

[Birdman]

The self levelling keeps the headlamps level with the road in relation to the position of the car. In otherwords at the cars normal ride height. If a load is placed in the car the headlamps will automatically dip so as not to dazzle other drivers.

The dirt will cause scatter.

How does the system know the car is loaded? I guess what puzzles me is how the device measures the change in front/rear pitch angle the laden car adopts. Does it measure front and rear ground clearance from a datum? Or alternatively, front and rear suspension compression against a datum? Or what??

 

[fuzzer]

You can't just swap the headlights for xenons, you will need the self levelling system as well and will probably need the option programming into the ECU to make it work.
The self levelling is a legal requirement.

but , don't the self levelers only level on startup of the car?

Im sure i read on here someone said something allong those lines. Shude springs to mind ..

 

[Bobby Dazzler]

but , don't the self levelers only level on startup of the car?

Im sure i read on here someone said something allong those lines. Shude springs to mind ..

I think that's probably right, as they only do their dance when they first switch on.

 

[richard]

Factory fitted xenons are always self leveling so they don't dazzle

On all the passenger cars (but I cant quite remember about the ML, as ours has xenons), they have manual leveling control if they *dont* have Xenons on them
[edit, MB may have become cheapskates and stopped fitting the manual leveling control to all their non-xenon cars)]

The leveling thing is a little thumbwheel (a bit like an airvent control, but smaller and wider) that you can rotate, with 0,1,2,3 markings on it - I think it would be on the dashboard on one side of the steering wheel. On the passenger cars its next to / part of the headlamp switch panel, but on the ML the headlamp switch is on the steering column rather than on the dash.

So, in summary - If you do have that headlamp level adjuster, you definetly don't have factory fit xenons.

If you don't have the adjuster then you may have xenons.


Cheers

Richard

 

[Dieselman]

The self levelling function is to keep the lights at eh same angle to the road whatever the load in the vehicle or if it hits bumps.
It is working all the time you just don't notice it.

 

[glojo]

On the early 211's that were fitted with active headlights, not only did the headlights move up and down when they carried out the self levelling check, they also moved left and right. It is certainly an eye cathing gimmick, just a pity Mercedes stopped this procedure.

John

 

[Birdman]

Factory fitted xenons are always self leveling so they don't dazzle... Cheers

Richard

Trouble is, I have Xenons that do dazzle. And washers of course, but the offside dipped Xenon is aiming high, in fact right into the offside hedgerow at nearly eye level (and we have a lot of hedgerows in Suffolk), which occcasionally bothers oncoming drivers.

So, is it an easy underbonnet adjustment or a dealer job using STAR computer software?

 

[Birdman]

"The dynamic self-levelling system of the Saab 9-5 employs sensors that are connected to the front and rear axles. Information on the compression rates of the suspension system, supplied by the sensors, is "filtered" electronically before being fed to a motor in the headlamp assembly. The motor reacts in milliseconds to actuate the position of the projector module so that the light beam stays at an optimum angle to avoid dazzling." - Valeo Group press release, March 5, 2002

Do they all work like this?

 

[Dieselman]

"The dynamic self-levelling system of the Saab 9-5 employs sensors that are connected to the front and rear axles. Information on the compression rates of the suspension system, supplied by the sensors, is "filtered" electronically before being fed to a motor in the headlamp assembly. The motor reacts in milliseconds to actuate the position of the projector module so that the light beam stays at an optimum angle to avoid dazzling." - Valeo Group press release, March 5, 2002

Do they all work like this?

Yes.

Either that or the car has to have self levelling suspension.

 

[Dieselman]

Trouble is, I have Xenons that do dazzle. And washers of course, but the offside dipped Xenon is aiming high, in fact right into the offside hedgerow at nearly eye level (and we have a lot of hedgerows in Suffolk), which occcasionally bothers oncoming drivers.

So, is it an easy underbonnet adjustment or a dealer job using STAR computer software?

It's a manual adjustment for the basic setting I believe, then the self levelling keeps it there.

 

[Birdman]

Yes.

Either that or the car has to have self levelling suspension.

I'm willing to take a bet that the regulations require both - ie cars with self levelling suspension still have to have an independently self-levelling Xenon system fitted. It's just the way the Eurocrats' minds work!

 

[Dieselman]

I'm willing to take a bet that the regulations require both - ie cars with self levelling suspension still have to have an independently self-levelling Xenon system fitted. It's just the way the Eurocrats' minds work!

Not according to the DOT.
http://www.mbclub.co.uk/forums/showpost.php?p=305465&postcount=8

 

[Birdman]

Chas opines that officially the DoT thinks aftermarket Xenons shouldn't exist. And as far as original fittings are concerned, the ball is very much in the international regulatory bodies' court.

I have found some of the original regulatory source material, at:

http://www.unece.org/trans/doc/2005/wp29/TRANS-WP29-2005-54e.pdf

from which the relevant extracts are,


6.22.6.1.2. The downward inclination of the horizontal part of the "cut-off" of the passing beam shall remain between the limits indicated in paragraph 6.2.6.1.2. this Regulation under all the static loading conditions of the vehicle of Annex this Regulation; and the initial aiming shall be within the specified values.

6.22.6.2. Headlamp levelling device

6.22.6.2.1. In the case where a headlamp levelling device is necessary to satisfy the requirements of paragraph 6.22.6.1.2., the device shall be automatic.

Comment: So it seems it is open to the vehicle manufacturer to decide how to self-level their Xenon headlamps. A victory for commonsense and a point in favour of the regulators.:bannana:

 

[Dieselman]

Sorry I don't understand you.
It clearly says in your post that if a levelling device is needed, as it will always be on a passenger car due to having suspension, then it must be automatic.

Thats a fairly crucial word "automatic".

 

[Bobby Dazzler]

On all the passenger cars (but I cant quite remember about the ML, as ours has xenons), they have manual leveling control if they *dont* have Xenons on them
[edit, MB may have become cheapskates and stopped fitting the manual leveling control to all their non-xenon cars)]

The manual adjustment thumbwheel is indeed there on the ML (without Xenons), below and to the left of the steering wheel.