W205 ILS Headlamp Fault

Rickoshea

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Hi, can anyone offer any help and direction on this one for us?

A week ago I was travelling down the motorway in HEAVY rain and I got an ILS headlamp is inoperative fault massage come up.

I got home to find a lot of moisture had got into the inside of the D/S headlight - not just misted, it was sopping inside!! After a few days the moisture disappeared but the fault did not......

What also started happening was the headlight alignment motor started twitching on the outside dipped beam light, whether the lights were on or not. Even after locking the vehicle, as power stayed on at the HL, the headlight motor continued to twitch back and fore for about 2-3 minutes after locking the car. Eventually the car would stop power to the headlight unit and the motor would stop. As soon as you unlocked the car again, the twitching started again!

When you switch the lights on, you can then see the motor moving the headlight back and fore.

I have removed the headlight today to investigate and have found that one of the seals on the ballast module has leaked water into the headlight - because the ILS control module is on the bottom (great place to put it with gravity playing its part here) , water has been getting into the module and corroded the metal case onto the PCB board inside - I have cleaned it, re-fitted it but we are still twitching :-(

So I guess either the module has shorted and is knackered or the headlight motor has now developed a fault as well, with it continuously trying to move (or both).

I've got a few quezzie's for anyone in the know on this subject.

Q. has anyone else seen the same fault and what rectified it? New module or did you have to replace the headlight as well? I'm hoping its just a module as its £100 v £500, so may try that first to see it stops twitching!

If I was to get another one off fleabay or order one new (aftermarket), do both options still need coding onto the car? Is the coding of the module unique to my car?

I saw on another post a moment ago that a company on here can do remote coding with the chassis number - could this be done in this way or is it only certain faults they can sort? Anyone used them?

Any experience, help and guidance would be greatly appreciated, as I did do the 'walk of shame' into the MB dealer on Friday for the first time, but no-one from service was willing to help or offer advice with out me getting my credit card out first. As I've only bought it earlier this year, I did ask some other questions like how much would its service be, but that was too much hassle as well and was told to go online and I'd find all the answers!

In true Starwars style - "Help me 'MB-One members', you are my only hope" :)

Thanks in advance,

Graham
 

Alfie

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Sounds like you need a new headlight. New they are about £1,000!
Each one is coded to the car so its not a straightforward swap im afraid.

If you do get one on ebay make sure it is the same part number.
 

richard

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To expand on Alfie's answer. The LED controller is used on many headlights, but when you install a new one you set it up (using the barcode on the headlight) to tell it what power to put on each channel - this is done with Xentry Diagnosis and a 2D-barcode scanner. The trouble with using a used controller on an existing light is that if it has come from a headlight with a different bar-code (i.e definelty a different car, or just a different part number headlight on same car), it can blow up the LEDs in the headlight by feeding them too much current.
So in reality, you have to get a new LED controller not a used one and it has to be set-up using Online Xentry Diagnosis and the 2-D barcode scanner. But, of course if the inside of your headlight has got wet then the motors will fail or the LEDs will fail, so as he says it is probably better to find an identical used unit (same part number) with all the controllers included which will have been set-up to that head-light already.

Sorry for bad news ..

Richard
 
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Rickoshea

Rickoshea

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Thanks
Sounds like you need a new headlight. New they are about £1,000!
Each one is coded to the car so its not a straightforward swap im afraid.

If you do get one on ebay make sure it is the same part number.
Thanks for the heads up Alfie
...
 
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Rickoshea

Rickoshea

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To expand on Alfie's answer. The LED controller is used on many headlights, but when you install a new one you set it up (using the barcode on the headlight) to tell it what power to put on each channel - this is done with Xentry Diagnosis and a 2D-barcode scanner. The trouble with using a used controller on an existing light is that if it has come from a headlight with a different bar-code (i.e definelty a different car, or just a different part number headlight on same car), it can blow up the LEDs in the headlight by feeding them too much current.
So in reality, you have to get a new LED controller not a used one and it has to be set-up using Online Xentry Diagnosis and the 2-D barcode scanner. But, of course if the inside of your headlight has got wet then the motors will fail or the LEDs will fail, so as he says it is probably better to find an identical used unit (same part number) with all the controllers included which will have been set-up to that head-light already.

Sorry for bad news ..

Richard
Thanks for explaining things Richard. I was hoping to getting a new module (as the cheaper option to start with) but my head tells me that something has gone wrong with the headlight motor as well....... It all lights up, it just tries to do its alignment movement and jitters back/fore

Just to check my understanding then that the module is coded against the output of the light and not specifically to the actual vehicle it was originally fitted to, so if I manage to find a headlight of the same spec and complete with its module, it should plug & play? Or will the car still reject it and I still need to get it coded to my car?

At the moment, I can only find bare headlights without the modules (second hand) but the same part number - if the headlight was the same part number and I tried the old module initially in the new headlight (hping that its ok), would that potentially work, re: re-coding or would I still need it setting back up again through Xentry?

Lastly, I'm interested in investing in something that I can diagnose issues myself (with caution) going fwd - can Xentry be purchased, run on a W 10 laptop and then connected to my motor (with something like a RS232 lead/ multiplexer/OBD2 connector) or do you need a laptop running it already - I have seen some Dell units with it pre-loaded? I can see versions of the software are available on fleabay - or is it only licensed through approved workshops.... you also mention Online Xentry?? is that another up-to-date version? sorry if its a stupid question but every day is a school day at the moment!!

Been around cars all my life and work in IT, so I can hopefully put a bit of knowledge from both (2+2) together and come up with 5!...or a bigger repair bill :)

Thanks in advance, Graham
 

unimog

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Have you owned this car from new? If not, Check the light assembly has not been previously repaired, parking knocks can break off the headlight mounting tabs, and the 'repair kits' for the standard headlights are not supposed to be used with these units but people do, the kits are shit and involve screwing into the lamp housing, which leads to it leaking (a friend had the exact same problem with an ex lease car, someone had done a cheapo repair).
 
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Rickoshea

Rickoshea

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Have you owned this car from new? If not, Check the light assembly has not been previously repaired, parking knocks can break off the headlight mounting tabs, and the 'repair kits' for the standard headlights are not supposed to be used with these units but people do, the kits are shit and involve screwing into the lamp housing, which leads to it leaking (a friend had the exact same problem with an ex lease car, someone had done a cheapo repair).
Hi Unimog,

Thanks for your advice. No, the unit hasn't been repaired.

Was your friends headlamp continually twitching as well?

How did he end up sorting it?

Thanks
 
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Rickoshea

Rickoshea

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Hi Unimog,

Thanks for your advice. No, the unit hasn't been repaired.

Was your friends headlamp continually twitching as well?

How did he end up sorting it?

Thanks
New headlight unit or was it a module issue?
 

Alfie

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Thanks for explaining things Richard. I was hoping to getting a new module (as the cheaper option to start with) but my head tells me that something has gone wrong with the headlight motor as well....... It all lights up, it just tries to do its alignment movement and jitters back/fore

Just to check my understanding then that the module is coded against the output of the light and not specifically to the actual vehicle it was originally fitted to, so if I manage to find a headlight of the same spec and complete with its module, it should plug & play? Or will the car still reject it and I still need to get it coded to my car?

At the moment, I can only find bare headlights without the modules (second hand) but the same part number - if the headlight was the same part number and I tried the old module initially in the new headlight (hping that its ok), would that potentially work, re: re-coding or would I still need it setting back up again through Xentry?

Lastly, I'm interested in investing in something that I can diagnose issues myself (with caution) going fwd - can Xentry be purchased, run on a W 10 laptop and then connected to my motor (with something like a RS232 lead/ multiplexer/OBD2 connector) or do you need a laptop running it already - I have seen some Dell units with it pre-loaded? I can see versions of the software are available on fleabay - or is it only licensed through approved workshops.... you also mention Online Xentry?? is that another up-to-date version? sorry if its a stupid question but every day is a school day at the moment!!

Been around cars all my life and work in IT, so I can hopefully put a bit of knowledge from both (2+2) together and come up with 5!...or a bigger repair bill :)

Thanks in advance, Graham
Online Xentry is a genuine Mercedes supplied Xentry system and its associated multiplexor, connected via the internet and a secure Mercedes dealer login, to their servers in Germany. This is how the coding is all performed. The units on ebay will not come with the full factory support that you need to do online coding.

You can buy the genuine Mercedes Xentry system from Mercedes but you are looking at about £10,000.
 

Vivian

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It is expensive to buy a complete headlight. It should be that the ballast was broken after being flooded. I wonder if you can provide the OEM code on the ballast.
 
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