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[jonnyatom5]

Hi
I have some bizarre electrical goings on with my ForFour, so I took it to an auto-electrician who said it was the SAM unit gone faulty and it needs replacing by a Mercedes/Smart dealership, as they have specialist equipment to code the unit to the car. Now, since then I've been told the ForFour doesn't have a SAM unit. Could someone clarify this for me? I may then be asking possible reasons for the weird electrical problems (which I think is the affect of water ingress somewhere).

Thanks in advance, Garry

[Alex]

What are the bizarre electrical problems you are having? Maybe it's just a weak battery, very common this time of year

Tell us more about your problems.

And yes, forfours have a SAM, on the back of the fuse box i believe.

[funkydoodycool]

I guess there is a SAM, as that would be what holds the codes you can change with TAN coding (as I understand it).

The main difference with the forfour over the other Smarts is that the fuses and relays are all accessible from the front with the glove box removed.

Perhaps you don't need a new SAM, but just a go on a STAR machine (the specialist unit your electrician mentioned) to see where the fault lies, which should pinpoint EXACTLY where the fault lies.  I've seen my car on the STAR and it's incredibly detailed, far more than general OBD codes.

EDIT: I just saw your post on the other forum.  If water/condensation is in the car, its more likely inside the doors - a lot of people have been complaining of this in the last few weeks of stormy weather.

There are two holes to poke in the bottom of each door, which will clear the drains and drain the water.

[jonnyatom5]

Thanks for the repiles, they're very much appreciated.

Regarding the faults ... The symptoms are very similar to those purported on other Smart cars (though Roadsters and ForTwo's). Electrically not working are; Indicators, lights, quick windscreen wiper (though main wipers work), washer squirter, rear washers & wiper. Also the hazards are stuck on all of the time (had to pull the fuse to stop) and the towing button light is on all of the time.

It's got all the characteristics of a SAM failure and the intermittent nature of the fault (sometimes the hazards stay on, others they don't) suggests it's water based.

Can SAM's be dried out, cleaned and reinstated?

Cheers, Garry

PS:  funkydoodycool, I'll check the doors and see if water is in there, thanks.

[funkydoodycool]

In my small experience with electricals (mostly computers and guitar equipment) yes they can be dried out.  This assumes that fresh water is the cause.  Salt water, or pretty much any other liquid, you might as well forget salvaging anything.  Also if they're used wet there's a risk of shorts which will reduce your luck with fixing it once dried.

In fact computer boards can be washed - carefully - in your sink with Fairy liquid, rinsed well and dried thoroughly (a week in an airing cupboard on top of a towel) and be put back to normal operation.

[Alex]

Take out the glove box, drive in a nice warmed but well ventilated garage (underground car park) and run the engine with the airconditioning on, full fan speed, recirculation and direct the air at the footwell.

[djames108]

I believe there has been suggestions made over on smartmaniacs

Main points being;
Forfours dont have sam units, only an ECU
Forfours dont really have issues with leaking so faults with fortwo's and roadsters will not apply to this.
Condensation issues are likely to be due to door drains.
Check earth straps for corrosion as this can cause electrical mishaps
Also charge your battery as the level could be low as you have had it sttod for 2 weeks.

Hope I have covered all points and condensed it 

[mr singh]

http://www.evilution.co.uk/index.php?menu=info&mod=697

remove the glove box and have a look.

you could go for a long drive with the heater on full hot facing the feet... failing that get a small dehumidifier and leave that in the car over night, or during the day.

[Problemchild]

do they have SAMs? still don't think so!

the SAM on a roadster is like a sealed fuse box thing.

wipers etc have the relays on the main board behind the glove box.

maybe there is water ingress and thats causing the shorts but the relays and fuses and away from the bulk head so any ingress would have to be significant.

check the doors first to rule out them as a source of water.

The ECU is under the bonnet but if that was at fault then you'd have more engine problems i would have thought.

whats the voltage across the battery..... is the battery original or relatively new??


JJ

[jonnyatom5]

Thank you for all of the replies, again much appreciated.
I shall be investigating a little further this weekend and running the car for a while to try and dry things out. To compound matters, the battery has drained, so something is amiss, which could point at a battery problem, although the garage I took it to should have tested that and pointed it out.

The joys of a poorly car. I'm still not sure if it has a SAM unit or not. A costly trip to a SMART dealership may well be on the cards. I'll let the forum know the outcome incase anyone else has this problem.

[Alex]

Battery is number 1 suspect. The car has a SAM, it's on the back of the fuses and relays panel. ECU in the engine bay is another matter.

New battery first, if symptoms continue, check SAM for water ingress.

[funkydoodycool]

Don't go to Smart yet.

1) put a voltmeter (on 20v) across the battery terminals - you're looking for a fully charged reading of about 12.6V.  Below 12V and you've found the probable culprit.

2) change the battery as required.

3) buy/borrow an OBD code reader (mine was £30 on ebay and has more than paid for itself).  it's halfway to using a proper STAR machine, but will at least give you a list of stored codes to narrow down the problem.

4) find a reputed local indie Smart garage (we can help find you one I'm sure), as it'll no doubt be cheaper than going to MB, and the guys will have the same training, same equipment, and more than likely better experience with the forfour.

[CrazyG]

I think everyone would be surprised if it was water ingress into the SAM,
as no one up till now has every reported such a problem. The set-up of
the SAM and where it is is completely unlike the Roadster, and there should
be no water anywhere near it.
About the only possible reason/s for there being any is that the car has had
flood damage, and/or that the interior has been so water logged that when
it has dried out the condensation has got into the SAM. Either of those is
highly improbable/unlikely to be honest.

As has been suggested, start with the battery, then go to a Smart 'indie'
for a diagnostics check to see if the root cause can be indentified if that
doesn't resolve the problem.

[Problemchild]

what is the definition of a SAM??

looking at the list of relays, things like the wipers and indicators do not show up so clearly some unit that houses all these.

i know Tony from tune4performance @ s2smarts has rescued a number of smart SAMs before that have got wet.

JJ

[CrazyG]

SAM = Signal Acquisition & Actuation Module

The SAM controls the wipers, starting, horn, central locking, lights,
tacho readout, immobiliser, electric windows, electric roof opening...
in fact, pretty much all the non-engine electrics.

Oh, and all the SAM's that JJ mentions were for ForTwo's and Roadsters,
none for a ForFour....as none have needed 'saving' as yet !