Electronics gone crazy,possible rear SAM unit

[Gergely Ferenc Gyepesi]

Hi All,

I need some help.Last 3 days we had some crazy rain fallen.My ML320 CDI 2006 model has developed a leak through the driver's side rear lamp causing some water soak on the fuse board and the SAM unit.
Resulted that most of the stuff was not working by the morning.Such as windscreen wipers,indicators,backdoor,command -radio unit on and off,DSR fault,SRS fault,electric seats none works,diesel gauge,motion sensors so far these are I detected.
By the afternoon the DSR fault gone,Radio-command unit works,the windscreen washing units are working but the wipers are still not,SRS alert comes and goes.
What are the chances that the things will come back to life when the SAM unit dries out completely?
If not,is it a big job to change or would it be something different that has gone wrong and causing all this ****?
What generally can I do?-use a contact spray?-or what else?
That is the only car we got and transporting our family is paramount to be able to work and run life.
Please help if you can with advices!
Thanks a million!

Gergely Ferenc Gyepesi, Yesterday at 4:48 PM

 

[AnthonyUK]

I would also check the battery which causes those symptoms when low. The leak could have caused something to remain on and drain it.

To clear the SRS light it will probably need connecting to a suitable diagnostic machine.

 

[Auto Addict]

Try drying with a hair drier, gently, don't get it too hot.

 

[Mark A]

You need to find out where the water is coming from and sort that too (3rd brake light and rear cluster seals are common leak points on the W164).

You might be lucky and once dried out it may go back to normal but it’s more likely that the SAM has failed. A new SAM will need to be coded by a garage with access to STAR and as far as I am aware once they re coded to your vehicle they can’t be used on another (so be careful buying a used one off eBay as it may not work).

 

[Uncle Benz]

If its only just happened it's very likely you can save it. You will need to take the unit out of the car and open the black casing. If you haven't found it already it is way down there in the bottom of that back corner. You will find a bit of water inside the unit's casing when you open it up. A squirt of wd40 and some tissue will clean it all up, and pay attention to the plugs on the wiring loom too. They will need a squirt and a blast of air from an airline if you have one. It is possible to move the unit up higher and just get the trim panel back in place. Merc moved the unit to under the back seat in about 2010, so they knew all about this problem!

Oh, and you can recode a secondhand unit for these, no problem.

 

[Gergely Ferenc Gyepesi]

Hi Guys,
Thanks for the input.Uncle Benz I am taking it out and will clean it with Contact Spray and a toothbrush I found the sourse of the leak too which I will also fix.I am hoping that it will come back alive. I have a VAGcom code reader with an OBD 2 option and I will try to clear the codes with that as first attempt.Some of the things are came back but there is still a lot of none working things left.the problem is that the electric seats are also out so I cannot disconnect the battery.Any advice on that?

 

[LostKiwi]

Your vagcom will be unlikely to be able to clear SAM codes.

 

[Uncle Benz]

Seats are also controlled via the rear SAM. With luck your drying out will bring them back to life. You can disconnect the SAM without disconnecting the battery. I've done it loads of times and didn't damage anything.
Agree with LK, obd2 won't help you with rear SAM comms.

 

[Gergely Ferenc Gyepesi]

Ok.I order something made for Mercs,it should be ok until it’s arrive.I think clearing the stored codes will not affect the fix if it is going to be successful

 

[Mark A]

Oh, and you can recode a secondhand unit for these, no problem.

Yet another thing the main dealer and local indie have lied about. Any wonder I don’t trust them.

 

[Gergely Ferenc Gyepesi]

Hi Everybody,

I have good news.
I took the rear SAM Unit out,f-ing not easy.
I has about an inch water on the bottom.I need to find the ****** source of this ****** leak.
Anyway,i took it out,cut my hand about 6 times blood,water swearing all you can imagine.
Ok, unit out
opened it like a milk crate,lots of oxidation mark and still a little wet.
Cleaned it with MOTIP Contact cleaner very carefully.Dried it with a hairdryer.
Than I put it back but not where it was.Right now it is hanging in parallelly with the fuse board this way I can avoid not to soak into water.I cannot fully close the panel which covers the part of the boot but it is a small price to pay compare the money I would pay if it would burn out.Took me approx 3 hours,which is not bad considering that I had no idea how to release the panels and screws I had work it out as I was getting forward.Of course I had 2 screws left in my hand which I have no idea where should I put back
The great thing is that it works like a new now faults what so ever.
Than I gone down to the local Frostinger and bought a cover with hell stone protection,rain and UV ,just until I figure out the sealing of the back of the car.

 

[daibevan]

Well done! That's very good news.

 

[Uncle Benz]

Hi Everybody,

I have good news.
I took the rear SAM Unit out,f-ing not easy.
I has about an inch water on the bottom.I need to find the ****** source of this ****** leak.
Anyway,i took it out,cut my hand about 6 times blood,water swearing all you can imagine.
Ok, unit out
opened it like a milk crate,lots of oxidation mark and still a little wet.
Cleaned it with MOTIP Contact cleaner very carefully.Dried it with a hairdryer.
Than I put it back but not where it was.Right now it is hanging in parallelly with the fuse board this way I can avoid not to soak into water.I cannot fully close the panel which covers the part of the boot but it is a small price to pay compare the money I would pay if it would burn out.Took me approx 3 hours,which is not bad considering that I had no idea how to release the panels and screws I had work it out as I was getting forward.Of course I had 2 screws left in my hand which I have no idea where should I put back
The great thing is that it works like a new now faults what so ever.
Than I gone down to the local Frostinger and bought a cover with hell stone protection,rain and UV ,just until I figure out the sealing of the back of the car.

Invoice will be in the post

Very well done!! Saved yourself quite a bit there!

There is a grommet right in the bottom you can pull out to let the water drain, but you'll likely get a few more scratches.