Faulty N/S 2003 SL55 Xenon Headlight

[BRABUS R230]

I appear to have a fault in my NS/F Xenon headlamp, I have changed the Xenon bulbs, but no difference...
If I constantly switch my headlamps on/off (sometime around 10 times) after a while the light comes on, once it is on it will stay on...sometimes it might work for a few days without any issues, but sure enough after the car is not used for a week: it will stop working.

could it be the ballast?

 

[Naraic]

It could be...but it could also be a bad earth.

 

[whitenemesis]

After checking the earth, try swapping ballasts over. Or get the car on STAR and have the codes read.

 

[BRABUS R230]

After checking the earth, try swapping ballasts over. Or get the car on STAR and have the codes read.

Thanks.
Where is the ballast located?

 

[whitenemesis]

IIRC beneathe the headlamp units

 

[BRABUS R230]

IIRC beneathe the headlamp units

Bumper off and headlamp out?

 

[television]

On a 230 I would check the front SAMs they have a habit of failing particularly the near side one, the effect is that they cannot find things.

 

[BRABUS R230]

On a 230 I would check the front SAMs they have a habit of failing particularly the near side one, the effect is that they cannot find things.

Thanks Television, I will get that looked at next week.

 

[television]

Thanks Television, I will get that looked at next week.

When in, ask them to run a check on the SAMs, there are 2 one each side,


I can check later and tell you what SAM that lamp is on

 

[BRABUS R230]

Location of SAMs

On a 230 I would check the front SAMs they have a habit of failing particularly the near side one, the effect is that they cannot find things.

Where is this SAMs unit located?

 

[television]

Its by the side of the starter battery, and the battery has to come out to get to it in the oblong box,,, the SAM cannot be lifted out with disconnecting the thick power cable.

When your car goes in and it has a quick test on STAR take a note when it gets to the 2 SAMs and see if there are any question marks, also go to the CAN menu and STAR will check everything on the CAN

 

[Alex Crow]

All good advice above.
If the rest of the N/S/F lamps work OK, the ballast is next suspect. Swapping them over makes good diagnostic sense.
On some models you can get to both of them from underneath, without removing anything more than the undertray, but on an SL55 I doubt you can, with all the coolant pumps and so forth behind the bumper.
You will probably find the ballast fits many makes and model or car, so plenty of options on eg ebay.

 

[television]

Cliff, also when on STAR it does test the headlamps in the quick test, you can go to headlamps and activate them on STAR, turning them on and off, if the is a fault it will tell you what it is

 

[Alex Crow]

We had a '52 plate SL55 in today with a N/S xenon fault - the light would come on and work with engine off, but would then blink blink blink and go out with engine started.

The owner had tried 'new' everything in the headlamp already, with all relevant parts swapped out for others.

The fault actually lies with the N/S SAM unit, which is monitoring current supply and cutting the feed, erroneously.

We proved the diagnosis by swapping the feeds over, and the fault swapped sides too...

 

[television]

We had a '52 plate SL55 in today with a N/S xenon fault - the light would come on and work with engine off, but would then blink blink blink and go out with engine started.

The owner had tried 'new' everything in the headlamp already, with all relevant parts swapped out for others.

The fault actually lies with the N/S SAM unit, which is monitoring current supply and cutting the feed, erroneously.

We proved the diagnosis by swapping the feeds over, and the fault swapped sides too...

Then as my post 9 Alex, did you know that mercedes had got through more than 1000 of these SAM some 3-4 years ago. The reasón they fail is because the cables to the ABC go down through that fuse box and its open to the grill on the wing, wash the car on a hot day with a washer or hose and thats the start of it. The cure would be to vent the box at the top.

 

[Alex Crow]

The part has been superseded many times, with MBUK having sold 230 odd of the latest number - high volume for this chassis.

The unit itself shows no sign of water ingress whatsoever, with all pins bright and shiny. This was checked fairly early on in diagnosis, as we know water ingress is a common fault, obviously.

In this case, we have no need to suspect the SAM unit just yet, but I though it relevant and worth posting up.

EDIT: For reference, only the N/S/F Xenon is on the N/S/F SAM, with the all other front lamps controlled through the O/S/F SAM.

 

[television]

I had no signs of water in my box or in the ECU,not even a water mark, but it was so bad it blew the drivers SAM in my case. Never seen another where it blew both

 

[Alex Crow]

I had no signs of water in my box or in the ECU,not even a water mark, but it was so bad it blew the drivers SAM in my case. Never seen another where it blew both

Not quite sure how you blame water, when no sign of it?
I thought that picture you keep posting with the corroded pins was from your car??

 

[television]

Not quite sure how you blame water, when no sign of it?
I thought that picture you keep posting with the corroded pins was from your car??

I have handled much electronic apparatus with condensation damage in my life. many car ECU's and domestic things that have sat in a bay window or up against single glazing. Condensation is water in my eyes, there are other way of detecting water damage if you know what to look for by looking at the PCB.

In my case the car was very hot when I used a high pressure washer on it in Sweden. we know that water does not get in from the top, we know that the drivers SAM never gets the same problem, the only difference is the drivers SAM box goes into the car, and the passenger SAM box houses the electronics for the ABC, this box has a spout that houses the ABC wires, and ends by the vent in the front wing, now after a hard drive the ABC valve blocks do get hot, if you spray water in the wing vent you get condensation = water. As before there were no water marks on the same or fuse box. There is no other reason for it, no my SAM did not get like it just like that, it is a build up of deposits that eventually take no more and the SAM has gone. The air temp in Sweden at the time was +37c and the Air con going off and the parking brake on message came up as I left the car wash.

Yes I have helped many on here with this fault and on benzworld and it is more common in warm countries. Yes that picture was my SAM, but even without the green on the pins, if you know what to look for you can see that water has got in (condensation) The SAM runs very hot as well, and this does not help in that little box.

I do hope that is clear enough for you.

 

[Alex Crow]

I had no signs of water in my box or in the ECU,not even a water mark, but it was so bad it blew the drivers SAM in my case. Never seen another where it blew both

Which is it Malcolm?

You say that 'no sign of water in my box' in one post, then in the next you say 'Yes that picture was my SAM, but even without the green on the pins...'

Please, which is it? Green pins = king obvious sign of water damage.

In this case today, that I am relating, there was no sign of water damage - and yes I did check the PCB, clean bright and shiny.
Yes, I use a bright light and magnifier - no water/condensation damage.

I am no fool, working on Mercedes cars all day, and yes we see water/condensation damage often enough - but not in this case.

Malcom, there was no ABC ECU anywhere near this SAM unit - I'm pretty sure it is mounted in the driver's footwell, is it not? The wiring exiting this control unit case, that only houses a SAM unit, is perfectly sealed with grommets.

SAM units can and do fail, without any visual sign of water/condensation damage.

I have read some of your posts on R230 ABC on Benzworld, but cannot find the cases you suggest - please point me to them.