W164 Rear Sam - want to confirm broken before having it replaced

Bert_W164

Active Member
Joined
Jul 26, 2014
Messages
265
Location
Berkshire
Car
ML (W164)
Hi all,

I hope you're all well, I appreciate the easiest way is to get the car on STAR, but its not safe enough to drive distances (no indicators, central locking isn't working, SRS light on and other issues) and the mobile guys seem to be inundated at the moment (last chap said 2 week lead time)

Background:
- The car is a 2007 ML63 W164 M156
- During the thunderstorms a few days back, my alarm kept going off, then my central locking stopped working, but I could just about use the IR on the door handle
- It progressively got worse and the SRS light came on
- Indicators stopped working, wipers stopped working

Investigation:
- I took the rear SAM off and found water in one of the unused headers
- Opened it up and found a bunch of corrosion
- Desoldered the plugs and cleaned the corrosion and neutralised it with Bi-carb
- Iso cleaned the whole board and dried it thoroughly with a hair dryer and airing cupboard
- Placed it back on the car, unfortunately couldn't save it but my problems didn't get any worse (so my resoldering and corrosion removal efforts don't appear to have caused more damage

What I'm trying to achieve:
- Confirm its indeed the rear SAM before taking it into Mercedes for a rear SAM replacement
- Wondering if there's anyone with STAR in Berkshire area that would be willing to run a session (of course I'd pay for your time/fuel)
- Wondering if there's any other way to test the rear SAM, I'm fine with using a multimeter etc

Any help is really appreciated, I have an 8 month pregnant wife who is on my case that we need a 4 door car ASAP, so to get my money pit fixed or drive something more simple :(
 

Trickythemerc

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South Manchester
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CLK 220 CDI Sport 2009
Hi. You are at some point going to need someone with Star to sort this. If the SAM is faulty which sounds very likely,the new one will need to be coded to your car using Star unless you are lucky enough to find a used one from a car with exactly the same options as yours.
 
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Bert_W164

Bert_W164

Active Member
Joined
Jul 26, 2014
Messages
265
Location
Berkshire
Car
ML (W164)
Hi. You are at some point going to need someone with Star to sort this. If the SAM is faulty which sounds very likely,the new one will need to be coded to your car using Star unless you are lucky enough to find a used one from a car with exactly the same options as yours.
Hey buddy,

thanks. I've called Mercs and priced up the replacement unit (which wasn't bad in fact) just waiting to hear back on labour costs now. I was hoping in the mean time there might be someone on the forum with STAR that could confirm its indeed the rear SAM or with some advice to confirm it some other way.

I'm 99.9% sure its the rear SAM as I've checked all fuses with multimeter, main battery is holding 12.6-7v, aux battery is in good condition, alternator was replaced last year and so most other things have been ruled out.
 

Jobsworth

MB Enthusiast
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Sep 23, 2018
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1,071
Location
Horsham
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One or two...
It does sound most likely it’s all from the rear SAM. You must resolve the water ingress, or you’ll be doing it all again. The rear lights are the most common area, but it isn’t unknown for the rear 1/4 windows to leak too. It is *just* possible to bring the unit higher into the rear corner and get the cover door back into place to reduce the risk of losing another. Mercedes relocated the sam to under the rear seat on the facelift cars, so they knew all about it.
Some will tell you its online coding for this, but it can be done in standalone mode, it’s just time consuming to do. Each item has to be manually selected.
 
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Bert_W164

Bert_W164

Active Member
Joined
Jul 26, 2014
Messages
265
Location
Berkshire
Car
ML (W164)
It does sound most likely it’s all from the rear SAM. You must resolve the water ingress, or you’ll be doing it all again. The rear lights are the most common area, but it isn’t unknown for the rear 1/4 windows to leak too. It is *just* possible to bring the unit higher into the rear corner and get the cover door back into place to reduce the risk of losing another. Mercedes relocated the sam to under the rear seat on the facelift cars, so they knew all about it.
Some will tell you its online coding for this, but it can be done in standalone mode, it’s just time consuming to do. Each item has to be manually selected.
Hi,

Thanks for that info, its really helpful. I'm pretty handy but I don't have STAR/Xentry to do the coding myself, or to wait for a kit from China (though getting my hands on STAR/Xentry is going to be next on my list) - I've got my first born due any time in the next few weeks and need a 4 door car (plus that way I can be a cool daddy and tell my daughter I transported her home in a 507bhp AMG hehehehe), I've bit the bullet. £99 for diag, £550 for replacement + coding of the rear SAM)

I am planning to suspend or enclose the unit, and seal off areas of potential leaks - the irritating thing about this is its not due to my negligence or mistreatment/lack of maintenance, you'd think Mercedes would do a recall for the seals...but its a car from 2007 I doubt anyone really cares at this point.

Booked in on Thursday, I'll post some pics of the current SAM for anyone interested.
 

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