SAM units

[sean sherry]

After some digging on the Net, I now understand what a SAM unit is on the later model Mercedes. Apparently a faulty one was the cause of my battery drain the first time around, and the cause of my neighbour's dash flashing all sorts of issues.... Helmet will know all about this. They sit beneath the various fuse boxes and control what the driver commands . At $1800 each and not an uncommon problem ( a failing battery can upset them via voltage surges to their processor ). is not for the faint hearted , that's me ! Good news is that a pre- programed processor is available on the Net but requires a degree of skill to solder in to the board. It is a multi pin surface mount which is assembled by a robot and very tricky by hand. I'm going to talk to the guy who now runs my old Electronics business. ( Repairing Instrument Clusters ) to see if he's interested. Shouldn't be a problem with a steady hand and the right equipment.............Sean

 

[Helmet]

After some digging on the Net, I now understand what a SAM unit is on the later model Mercedes. Apparently a faulty one was the cause of my battery drain the first time around, and the cause of my neighbour's dash flashing all sorts of issues.... Helmet will know all about this. They sit beneath the various fuse boxes and control what the driver commands . At $1800 each and not an uncommon problem ( a failing battery can upset them via voltage surges to their processor ). is not for the faint hearted , that's me ! Good news is that a pre- programed processor is available on the Net but requires a degree of skill to solder in to the board. It is a multi pin surface mount which is assembled by a robot and very tricky by hand. I'm going to talk to the guy who now runs my old Electronics business. ( Repairing Instrument Clusters ) to see if he's interested. Shouldn't be a problem with a steady hand and the right equipment.............Sean

Hi Sean,
SAM,s have more than one processor , I would be interested to learn more about the repair, do you have a link?
On another note I have just down some training on the W212 e class , it has up to 96 control modules onboard (depending on options )
Is does however measure battery drain and can isolate battery if a drain continues 45 mins after shut down , very clever .

 

[Michel]

I have just down some training on the W212 e class , it has up to 96 control modules onboard (depending on options )
Is does however measure battery drain and can isolate battery if a drain continues 45 mins after shut down , very clever .

For those who are computer literate, the new S-Class has 34 millions lines of code

 

[Styria]

For the computer literate like myself, Gleaming Beauty's alternator died the other day without warning. I turned the key and the charge light was illuminated. I have since had it rebuilt by my Auto Electrician and the unit is back in the car. In between times, just to be certain of having a fully charged battery, the battery charger came to the rescue, and the job is completed. Phew, I must admit I am glad that I am computer literate. Regards Styria

N.B. I think it's frightening - those millions of whatever, and all those thingymigigs.

 

[sean sherry]

http://mbworld.org/forums/c-class-w203/303764-diy-rear-sam-low-cost-repairing.html

Hopefully this will open ok Helmet. you might have to type it into your address bar. There are 4 or 5 links in this site mainly to do with the physical aspect of changing the processor. The most interesting one is the explanation of the Processors and why they fail. E.g., Sometimes because they were never programed properly from new ! and can take a few years before problems surfaces.
........................Sean

Just tried it and it will open

 

[sean sherry]

P.S. since the Dealer fitted a new larger Battery etc our C Class GLI goes like a little Pocket Rocket. Auto Box now preforming as an Auto should.... with a responsive part throttle down shifts. No longer hangs on to higher gears till the death. Hopefully now I can go away and die happily !....... Sean

 

[sean sherry]

So far it seems that the electrical system being different from 2010 on, no one has cracked the coding for the SAMs. Probably as they are now just coming out of warranty. I've been thinking with my Battery drain problems , Mercedes may have the " Software Programmer" to erase the corrupted processor and reloading it. I'll try to find out. Computer Chips are very reliable unless something else upsets them. Water ,voltage spikes, erratic reference voltages , from bad earths or faulty Batteries ,over heated. None of this should be an issue on newer cars. ,
Still on a learning curve, a S.A.M. is a complex relay is the best description I've heard...........Sean

 

[6.9forever]

Just replaced battery for first time in my 41 month old C250CGI with 72500km. Was fine until about 36 months (end of warranty period), then failed to start on 3 occasions in last 5 months. On third occasion I relented and replaced battery and the roadside service guy said he really wasn't happy to sell me one as he said the genuine Mercedes ones were closely matched to the finicky controlling software and processors in the car's electrical circuitry. OK, but this meant a visit to MB Sunshine Coast, and $582 for the battery, $145 in labour and about $50 in sundries. Not a cheap exercise! At least I had two excellent coffees, got to look over a couple of CLAs in the showroom while they tried quite hard to sell me one (CLA45AMG on 12 month wait, then Agility finance strongly offered at $1500/month for 60 months, taking it 3 years past end of warranty ... As I drove away I reflected on the price of my current battery in the 6.9 - $235 from Autobarn and fitted by me in about 10 minutes.

For the labour charge on the C, they also elected to install updated software which they said would give them better assurance about electrical diagnostics in future and interestingly, a reduced tendency to battery discharge by accident.

If you have a modern Mercedes this is typical. But once out of warranty, $750+ for a battery I haven't even seen as it's under its plastic cover, is a relatively small cost. Makes you think very carefully about keeping these cars more than about 4 years, even though to date, this has been my only problem and I love the car. It's still on its original Continental SportContact 3 tyres too, though the back ones are now at legal minimum tread. I need to save the mortgage for new XWXs for the 6.9 as I don't want whitewall Maxxis and want to keep originality with the now dainty 14" bundts.

All good fun. Had a great drive in the Blattenhauser today - purred like a kitten. 35 years young. Will the C be around in 31 years from now?

 

[Helmet]

http://mbworld.org/forums/c-class-w203/303764-diy-rear-sam-low-cost-repairing.html

Hopefully this will open ok Helmet. you might have to type it into your address bar. There are 4 or 5 links in this site mainly to do with the physical aspect of changing the processor. The most interesting one is the explanation of the Processors and why they fail. E.g., Sometimes because they were never programed properly from new ! and can take a few years before problems surfaces.
........................Sean

Just tried it and it will open

Interesting reading, Did he actually get one to work ? The risk for failure is pretty high, you need a magnifying glass to see the solder joints .
To all of you with later model cars, make sure the key is out of the ignition when disconnecting the battery and you wont have a problem with the rear sam. Also keep drains clear as water ingress is the biggest SAM killer.

 

[sean sherry]

Interesting point about removing the key. Paul the Service Manager at Mercedes Sydney ,told me to always lock the car to ensure that everything shuts down when parked. The first time I had a flat battery was when I charging my wife's Mobile Ph. with the car in the garage. An hour later ....flat battery . Friends C Class , same result sitting listening the Radio for a quarter of an hour. I would take the Mercedes Battery comment with a grain of salt, if the original Batteries were so good , how come they all fail in early life. For me a battery has a simple job ,, to supply a clean steady 12 + volts . Of course Mercedes would say that wouldn't they !
And yes Helmet a magnifying glass is part of the equipment to work on a circuit board , everything become life size, but a steady hand is the key !
Sean