Steff95

I kind of did something stupid recently.. I listened to music on the radio for many hours while working on my car, and now it won't start. So I guess the electric starter doesn't have enough volts, so it won't even try to start.
I tested the battery with a multimeter, and it said 12volt, so it cannot be a lot drained, just a little bit under the limit for engine startup.

I'm a bit afraid of just simply just connecting the battery charger and start charging, because I see people writes about the electric system can be damaged when charging the battery.
Also it can be bad to remove the battery to charge it.. I don't understand why it has to be so hard to charge the battery safely on all newer cars/or cars with a lot of electronics..

Also I see there are two positive spots under the hood, one terminal at the battery pole, and another positive point close to the battery. Why is that? Just so it's easier to jumpstart, instead of removing the housing over the battery etc.?

And does it matter if I connect the battery charger pins to the battery poles, or should the negative be connected to the frame/engine instead of the negative battery pole?

VVF

I would just disconnect the negative battery terminal (or both terminals to be safe) and then connect the charger to the battery.
It's perfectly fine to disconnect the battery - otherwise how would you change, say, an alternator?
You will lose your "miles since last reset", and will have to resynch the windows and sunroof. Other than that everything will be fine.
Remove the negative battery terminal _first_.

Steff95

Hmm okay. Is there any advantages of connecting the negative charging pin to the frame/engine instead of the negative battery pole? I see many people do that.

VVF

Moving a potential source of sparks away from the gases produced during charging maybe?
But the battery vent goes way down into fender area AFAIK.
If you disconnect the negative cable you will have to connect the charger to battery pole though.

I think the only consideration for disconnecting the battery before charging is the pulses from the charger possibly affecting the car's electronics.

So far I haven't jumped my car, but have jumped a Taurus and a Jetta, from my car. No issues.

Steff95

Omg... so now my sam module is probably fked up.

I get a "display faulty, visit workshop!" error when I start the car.
Gas gauge doesn't work, can't move my electric seats, can't release headrests in the backseats, indicators/blinkers and wipers doesn't work, cruisecontrol doesn't work, can't open trunk, fuel cap won't lock, ETC ETC.

And to lock/unlock the car I have to stand close and point the remote directly at the drivers door.


How the heck did this happen?? I disconnected the negative chassis lead from the battery pole. And when I charged I connected the positive lead first! I thought I did everything right??
Do I have to get a new sam module now or can it be reprogrammed? Cheap ****ty sam module.. I don't understand why this would damage it? I searched, and it seems to have something to do with the processor inside or something? But let's say I have to change the battery in a year or two, how the heck can you do that without destroying the sam module? :S

One thing's for sure. I'll never ever EVER use this car to jumpstart anything!

Carsy

You may not have charged the battery sufficiently . See if things improve after a longish run. Strange things occur with a weak battery in the w 203..

Also check all the fuses.

Good luck.

Steff95

Okay thanks, I'll give that a try! How long do I have to drive approximately? An hour?

But it seems weird though, since the electric seats and blinkers still worked before I charged the battery.

By fuses, do you mean the ones in the trunk with the rear sam module only then? Because I can't open the trunk, is there any way of opening it mechanically?

VVF

wow... Hope things get better after further charging.
How old is your battery? 12 years? Then you are overdue for a new one anyway.

Steff95

No I think my battery is pretty new, but it was just an example. I mean, how is it even possible to replace a battery without damaging that stupid sam unit? How annoying.. I'm guessing this is going to be expensive here in Norway..

Does anyone know why this happens and how?

And how do I get into my trunk? I don't think I got the keys when I bought the car.

VVF

https://mbworld.org/forums/5720593-post24.html

Steff95

My battery should be good, though. All of this worked before I disconnected and charged the battery. Why would the battery be worse now?


And I have no idea how to get into my trunk!! I have searched, and the only way seems to be with the metal key which I don't have? Because to fell down the seats you would have to be in the trunk also?
Jesus, what a mess.

VVF

Ok, then this is a good thread for you
https://mbworld.org/forums/c-class-w...repairing.html

Steff95

Thanks, I've already read this thread, though.

Problem is that I can't access the sam module because the trunk is locked..
And it seems like the processor is hard to reach on the early models, unless I got a newer version of the module, but I doubt it.. If it was a newer one it shouldn't have blown.

Carsy

Try this thread https://mbworld.org/forums/c-class-w...2003-c230.html

You may need a locksmith or a MB dealer to access the boot.

Try running the car at 15000- 2000 rpm for an hour whilst parked to see whether a battery top up fixes the problem.You can't drive with no signals.

Use the search feature on this forum. There has been a lot of problems with the early 203 SAMS hence a lot of information.

Good luck & let us know how you go.

Steff95

It seems like the problem in the thread you linked isn't the same as I have. The symptoms I'm having looks to be the rear sam malfunctioning.

Sorry, I forgot to mention. Yesterday I started up the engine, and it was probably running for 30-60 minutes. The engine started up instantly without any struggle, so the battery seems fine too.

Yeah, I've been reading maany threads regarding this sam module, can't seem to find any further useful information. I guess I'll have to call my dealer tomorrow and ask how much this will cost, or look around if I find a sam module at a reasonable price. This is probably going to take a couple of weeks unless I find the part here in Norway..

I'll let you know how it goes for sure

VVF

There is one "cheap" on ebay, approx $220 shipped:
http://www.ebay.com/itm/MERCEDES-W203-C230-C240-C320-209-CLK350-REAR-SAM-MODULE-0035455201-/251252709722?pt=Motors_Car_Truck_Parts_Accessories&hash=item3a7fd4195a&vxp=mtr

Steff95

Thanks for helping, I apreciate it! It seems the used parts is costing the same here though at wrecking yards... The problem is I don't know if it's the updated versions or not, does anything know how to see that? Is the newer versions another brand, or is there any numbers I can look at? Because if I'm buying another old version, it's probably going to blow again if I have to charge my battery again or replace it... :/

The dealer here wanted 800$ for the part and another 300$ approximately to replace it.

But does a used part have to be reprogrammed/reflashed when put into another car?

VVF

This is what EPC shows for my 2004.5 C230:
(in order from oldest to newest)

A 209 545 01 01
A 209 545 07 01
A 203 545 32 01
A 203 545 38 01
A 203 545 34 01 (why is this less than previous?)
A 203 545 47 01

The name is "Electrical Center. Signal acquisition and actuation module with rear fuse and relay module SAM/SRB"

Seems like # 52 01 from ebay ~ # 07 01 from EPC catalog (from what a quick google search returned)

I think someone said in the DIY SAM repair thread that you will have to program the stuff through STAR.
In lieu of $300 dealer cost it might be better to buy a STAR clone for yourself... Just a thought.

Steff95

Hmm, I think your numbers are different since you have a facelift model.

But isn't the star program very expensive? And yes I knew it had to be programmed in this program, but does that mean the used parts also? I read something about reprogramming to get the alarm to work? But I'm not sure.. Say you take a sam unit from an identical car for example

VVF

STAR clones cost about 300-400. I forgot the link, but you can search here on the forum.

For the part#'s you can probably contact parts.com customer service and ask there. They should be able to tell you what is the updated SAM number.

I don't know about programming to be honest.
You can try to connect a SAM from an identical car. Best case it will work right then, worst case you will need to program it

Steff95

True, true. Seems like most of the used sams for sale is early models though. Don't know if I should try a old one, or get an used newer version. Is there really much of an improvement? I couldn't find any info while searching regarding this. I could try send parts.com a mail though.

Steff95

Does anyone know how to replace this sam unit safely then? Do I need to have a small moped battery or something connected at all times when pulling out and installing the sam module? (when I pull it out of the other car, and install the module in my car)? What's the trick?

VVF

Just thoughts here, not an advise

If the other car's battery is disconnected - I would just pull the SAM (remember it craps if you connect the battery)
For your car - you figured out that if you dis/re-connect the battery, SAM craps. Which means you probably have to connect it with battery live?..

Steff95

Yeah that's true, if the battery is disconnected already from the other car.. Don't know how to do it if the battery is connected.

I don't know what happens if you connect the sam when the battery already is connected in my car either. I'm afraid the front Sam might blow if I disconnect my battery..

VVF

I think in this thread https://mbworld.org/forums/c-class-w...repairing.html someone recommended connecting SAM with battery connected. But I kind of think it is similar to connecting the battery with SAM already there - you get some current spike either way(?) Maybe not as strong though?
UPD - people there think SAM gets blown during disconnection of battery, so...