It has been over a month now and I still never got the answer to what I though was a simple question..."How do you adjust the headlights on a 2003 SL500?" I posted on two forums for Mercedes and it seems not a single person has a clue.

By my own research over the last couple of weeks I have found out that all 03 SL500's have xenon low beams (which are the ones needing adjustment). I live in the USA so these cars have a shield that blocks a portion of the beam and that shield is adjusted with an electric motor that is supposed to keep the beam adjusted at the same level no matter what the load or whether the car is under acceleration or braking (nose rising or lowering)! Now that is technical I must admit. I still believe that the initial beam hight can be adjusted, as my car only lights the road out to about 100' and that is dangerous...!

When I first got this car, used, the service writer at my local Mercedes dealer told me that only a small number of owners even read the Owner's manual on their car and about 95% do NO maintenance themselves at all. For a guy that has changed his own oil and done most of the routine maintenance on every vehicle ever owned....I found his comments pretty hard to believe.

But now that I have been reading this forum for over a month...I believe him.

I guess I will just have to pay the dealer $75 bucks to turn a screw somewhere to raise my low beams an inch...and that really bums me out. It is not really the money...but the time and hassle for an appointment and the trip...just for a mechanic to twist a screw a half turn...oh my.

Good luck on getting any technical questions answered here....but if you need to know what wax is great....I think this might be a good place.[/align]

 

Excuse us. Sometimes people are very, very busy in there own careers and off‑duty life. We see postingsat an internetwebsite discussion forum, want to reply, just can not squeeze minute into their 16hrs days away from home. Try www.alldata.com . Many user technical steps can be found. Headlight adjustments are one. I know as I have used it to check my headlights alignment. Well worth the annual fee. I have replied to many postings in this forum, just trying to helpout people. For my car, the headlights adjustments are easy, done by small *****, located under a black plastic cover just above and behind the headlights, and the cover has embedded on it a small symbol of a headlight. My headlights also are auto adjusted by the rear selfleveling monitoring system, and there is a switch on the dash to further move the lights in a small angle range for even more precise alignment while driving. I usually let the computer module do all the work and keep the dash switch in the center position. Try looking for these access covers in the engine compartment and let us know.

 

bb, that's kinda funny. OTOH, who ever said this is a good place to post if you're having technical difficulties?

FWIW, I've tinkered with the headlight adjustment (fogs, too) on our E Class cars. The directions are in the Owner's Manual. I can't say I've seen adjusting instructions in manuals for other vehicles, so Benz is cool about including that detail.

Take care.

 

Hi,
I've been away so did not see your post.

Headlamp adjustment is something that once set should never need adjustment.

With the intro of Xenon headlamps it is EXTREMELY IMPORTANT that they are set correctly since they have the capacity to SERIOUSLY (DANGEROUSLY!) DAZZLE other drivers and should therefore only be set using the correct equipment.

As you have determined the headlamps are "self levelling". This feature is a legal requirement and involves some sophisticated electronics which could be at fault. This self levelling takes into account not only static vehicle loading but also acceleration effects etc. Xenon (and in particular Xenon Projector (big clear lens) lights need to be controlled within extremely tight limits to get optimum performance. Too low and any benefit is lost. Too high and they are dangerous. The difference is in the order of a fraction of a degree which cannot be determined on a gargae wall / run up the road at night.

Maybe your personal preference for low beam setting is higher than the legislative (safety) requirement and if so adjustment COULD cause problems to other drivers..

If the car is 2003 why has it taken 4 years before the need to adjust the headlamps has come to the surface?

The key MUST BE why do the lamps need to be adjusted. Maybe the vehicle has had front end accident damage which would at least explain the need for the datum to be reset BUT this should have been done at the time.. Maybe it is not the static (datum) adjustment that is at fault but the dynamic self levelling system.

If indeed you insist on wanting to do such a static datum adjustment yourself any mechanism for so do will be apparent by careful examination of the headlamp unit. There will be two screw mechanisms to control lateral and vertical positioning. If no such mechanism is present then the adjustment is determined by the offset of the dynamic adjustment stepper motor in which case you will have no alternative but to go the dealer.

May I just add that as technology changes the ability for a DIY'er to modify factory setting has been INTENTIONALLY made more difficult. This is partially because specialist software is often required to adjust digitally controlled devices but also that the manufacturers have taken the opportunity to reduce tampering in the interests of legislation (or safety) WHILST of course leveraging the commercial opportunity it presents.

This is a situation COMMON TO ALL MANUFACTURERS using state of the art electronics, most of which was introduced on European models (lead by Bosch) but is now standard spec across the world. ABS, ASR, EPS, BAS, multiplexing, electronic engine management, adaptive cruise, night vision radar (Xenon/Infra red headlamps) etc.

In time I'm sure that certain aspects of these elctronic circuits will become standardised due to legislation (Like OBDII engine diagnositcs) but at present there is no such requirement to standardise and the dealer wants your money!!

Hope I've painted a picture why you should not adjust these lamps yourself however if adjustment does exist it will become apparent upon examination of the lamp body / mounting.

Good luck.

Stuart

 

Thanks Stuart....you sound like you know your stuff. I have only had this car a short time.It was owned by someone with a large collection of expensive cars and this one was seldom driven...an 03 with only a little over 5K on the odometer! The car has never been rained on much less wrecked and looks new inside and out and there is hardly any dust on the engine even! I noticed the headlight issue the first time I had to use them. They only light the road out to about 100' or so....that is dangerous to me.

Well I have an appointment Thursday with the local Benz dealer...will post the outcome.

Thanks again Stuart,
Ken

 

Hi Ken,
I'll be interested in what the dealer comes up with.

Since they will have to (or at least they should!) connect the car to the diagnostics computer get them to give you a MB Star "Quick Check" hard copy report for all the cars systems at the same time. This will show if anything else on the car is potentially the source of a problem. (basically a free" ride) whilst you are at the dealer. This takes about 30 secs once the computer has been plugged in so watch they don't run off with your wallet!
Recognising the history you have now supplied I'm even more convinced that the lights will be found to be OK but of course a proper check will settle the matter.
Your car is a 97 and On Board Diagnostics systems were not as advanced then as they are now so I can't be 100% sure what checks are actually held in the system. Likewise Xenon lamps were in their infancy in 97 and I had previously thought they were intro'd about 99 on the w220 but it looks as though I may have got that wrong.

If the lights are working correctly (from the stepper motor point of view) you should be able to observe the level of the headlamps change a couple of times before settling at the new datum position immediately after the lamps are turned on. Point to ground, point up, point down, point up to correct level. The stepper motor has to check extreme of travel before applying whatever offset + attitude correction is required and stored in its memory. Of course this datum offset COULD BE wrong but I can't think why on such a new vehicle.

I take it that you couldn't find any MECHANICAL way of adjusting the lamp body/mounting.

I look forward to hearing the outcome.

Stuart

 

Stuart,
This car is a 2003 not a 1997. I have the Mercedes "Shop Manual" DVD and it was absolutely no help as far as finding any "manual adjustments" for the lights unless the car was built for the European market,if so, there was suppose to be an adjustment lever inside the light behind the larger round plastic cover on the back of the light.There is nothing inside that looks like what is described in the DVD.There is one screw accessable from the top thru a think plastic cover, as viewed as soon as you open the hood and lookstright down on the light, (that I was told by a local Shop, that works on older Mercedes, that was the hight adjustment screw.) But, it does nothing, I tried it. I hate to say it....but this does look like Rocket Science. Will see what the dealer says....Later.

Thanks,
Ken

 

Hi Ken,

Usually a matter of rocker science (electronic adjustment/wizardry) + old fashion manual mechanical adjustment.

If the "adjuster" you have moved did nothing then maybe it has been moved passed the limit of its travel and become disconnected, which might also explain your problem.
Too difficult to describe this sort of stuff without the bits in front of you.

Good luck.
Keep a tight reign on your pocket book!

Stuart.

 

Well here is the skinny after a trip to the dealer and $56 lighter in the pocket book. The 2003 SL models have a sensor on the sway bar under the car as well as other level sensors that talk to a controller for the headlights. Based on the information those sensors send, the low beam head lights are adjusted by an electric motor to keep them aimed at the same point.

The car's computer has to be put in a diagnostic mode in order to adjust the lights and there is a tool that is placed in front of the car to read the aim point. My car's lights were adjusted dead on at the "zero" center point. They can be adjusted 4" up or down (as measured 25' out). My technician raise my lights 3.8". The tech also told me they have a spot set aside in the garage where the floor is level and special tools and computer software to adjust the lights. The days of pulling up to your garage wall, turning a screw and doing the job yourself is over my friends....this job IS rocket science!

Ken

 

Hi Ken,

As I tried to explain.

......May I just add that as technology changes the ability for a DIY'er to modify factory setting has been INTENTIONALLY made more difficult. This is partially because specialist software is often required to adjust digitally controlled devices but also that the manufacturers have taken the opportunity to reduce tampering in the interests of legislation (or safety) WHILST of course leveraging the commercial opportunity it presents.

HOWEVER was the setting wrong and therefore in need of adjustment OR was it as I suggested a matter of personal preference? These systems tell you when there is a problem and this is why I suggested there was possibly nothing wrong.....

Maybe your personal preference for low beam setting is higher than the legislative (safety) requirement and if so adjustment COULD cause problems to other drivers..
4" at 25ft. That's even closer than I thought. It is usually referred to as an angle tolerance (fraction of a degree).

IF the setting was wrong the question WHY needs to be asked. The data used to drive the headlamps is shared with other systems (if there are any fitted to your car) e.g. Airmatic = Air Suspension and Self Levelling suspension for towing etc. I'm convinced it would not have been wrong from the factory since amongst many other responsibilities I used to be reponsible for the automated equipment doing this sort of Quality check at a large automobile manufacturer and the results were statistically fed back into upstream process whenever any drift in baseline datum setting (not the adjusted figured) so that action could be taken to headoff any deviation.

Glad your problem now resolved. 32 USD was not an unreasonable price. It could easily have cost a lot more. If one of the stepper motors was dead it would have been X00's USD. I believe the Xenon bulbs are in the order of 100 USD!

incidentally this "Rocket Science" as you refer to also controls most electrics on the car from the seasts, wimdows, indicators, engine, trans, brakes, steering, instruments, cruise, radio, ACon etc etc etc. Everything is linked into an ECU to control function DIGITALLY which needs software/specialist equipment to determine what is going on if things go wrong.

Both my S Class and SLK have Xenon and both have mechanical adjustment in ADDITION to the self levelling stepper motors.

It appears that this mechanical adjustment may has been removed as a cost saving / model year update since FINAL aiming on xenon is determined through software.
Stuart