RipN Ray

I just want to put some good news in this thread, because it scared me when i first read it.

in my 02 c240 i followed the directions in the manual; undo the negative first and put on last, then re sync the windows by holding the button up for a few seconds. i think there was an edl warning that went away after i restarted it. other than that eveything was fine

phingoc

i work at a mercedes dealer in norway, and the usual things are:

1. The sam control modul dies(w203 before facelift)
2. Steering angle sensor must be adapted(steer full to left, and then to right, then to center and turn off and on the engine)
3. variuos fault codes that the owner wont see, but comes up at the star diagnosis machine(under voltage faults)

when the sam dies, everything in the rear of the car wont work, central locking, fuel filler cap, lights etc. a good trix to this is to plug a charger to the battery cables before disconecting it, just to suply power to the car while the battery is disconected.

sorry for my bad english.

Scatterblak

Nice attitude. No, it is not 'all there'. I have the same problem and 20 years as an engineer, and I've meticulously followed all of the procedures in the manual. I’m hoping that some of the guys here who’ve actually worked for MB can shed some light on potential unpublished functions available through the command interface.

Here’s an idea – if you don’t know the answer to the problem (Which you don’t, or you’d have presumably posted it), why don’t you just not post?

Thanks.

Television

This was written by an MB techie in the UK and a safe way to do the job.
---------------------------------------------------------------
After so much right and wrongs on this subject a couple of us thought it might be helpful to other members to help explain what can go wrong with battery changes and jump starting.

First of all i wouldn’t recommend anybody jump starting from there car to another or other way round!!!

You can buy jump and carry booster packs which have surge protection built in, when you connect up to your flat battery the jump pack slowly increases the voltage up to 12.50 volt, hence no surge, also taskmaster sell a good set of jump leads which have a surge protector built in.

Flat batteries

For whatever reason you might find yourself with a flat battery, rule number one, don’t jump from another car! The other car would be running and the battery voltage would be far higher than the safe 12.50 volt.

203 (and other) models tend to blow the rear sam, have also seen dashboard modules blown, EIS blown, front sams and so on, all due to jumpstarting! I admit sometimes you might not have any other choice but to use jump leads, if that’s the case my advice would be, key out, heads lights on, other car not running, connect leads, start other car, tick over only, turn light back off and let other car just put some charge in for 5 mins, no need to rev the hell out of the car your using to jump, max outlet from alternator is around the 1500rmp mark, then try starting.
As said that’s only my advice!!!!

Battery changes (203)
Needed will be a set of leads and a slave battery,
push the red button on the bonnet stay in to open the bonnet to its full
just next to the battery you will find a red cap with a + on it, this is the so call jump point, this is where you would connect your positive lead from the slave battery, on the off side you will find an earth point bolted to the top strut, use this for your earth lead from slave battery, now the car is live, disconnect the positive lead from the battery and tape up fully, this will stop any shorts, where the lead comes thought the plastic, you can lift up the small bit of trim and remove lead right out the way, just be aware that the clips holding this trim are very sharp, then what I do is pull the lead right out the way and tuck it under the brake pipes, hence the tape, disconnect neg lead and battery clamp, replace battery, do not disconnect slave battery until both leads are back onto new battery otherwise damage COULD be caused.

This is only the way I change them and I’m sure other people will have their thoughts on this, if it saves just one person spending out then I will be pleased,

if you want to add any views or anything you think I have missed Malcolm please feel free to correct or add,
Cost of rear sam about £225!
cole

ojra89

Hey guys,

Im pretty new to these forums, Ive been on for a while reading, and once I become more experienced I will begin sharing...


I live in Chicago,

but my car is in Nicaragua (Central America, not to insult just making sure )

it is a C200k, (european configuration, OEM HID, HEadlamp washers, etc.

So my car is back at home with Dad now, and on his last call he told me that the battery had died, so he told me that he was going to charge it and put it back in, So after that I wenton the forums and saw that there was a risk of a lot of things messing up if you unplug it wrong,


to make the story short,

He had already unplugged it, (he doesnt remeber in which order) and was charging it, I told him to wait to put it back it until I got there and got some feedback from the forums...

my question to you guys is, is there anything that can be done at THIS point that can prevent the rear SAM to be blown? in Nicaragua, we do not have the roadside assistance or anything similar.. theres a dealership but am not sure how helpful they willl be with explaining how to change the battery?



any suggestions? Thanks guys!

francoisisp

I'm trying to buy this 2001 c320 from a guy, he said the blinkers dont work and the windshield wipers dont work because he changed the battery. the car as 100Km on it he wants $6k for it is it something easilly fixed if so how much am i looking to spend. by the way how much does a rear sam cost. i've heard allot about those but i dont know what they look like or how to find a new one.

thanks you for your help

va3wyu

I changed battery on 2003 C240. There is no error codes, nothing to adjust. Everything works as usual.

sfkoldun

Well here is my 2 cents. I had "undervoltage consumer defective" too. I did all sorts off tests.
1. measured voltage with car idling, I was getting 13.2, but after couple of minutes it slowly droppes down, I thougt it could the alternator

2. measured voltage with engine off, I was getting above 12 volts, and what I thing the "undervoltage consumer defective" shows up only when voltage drops below 12 volts.

3. next morning could not start the car, the cluster was lighting up but not enough juice to start the car, I got jumpers from other car (not running) cliped the other end to my battery, start the other car let it run for about 5 min, shut it off, remooved jumpers, nad my car CAME UP. Well it made me think the alternator was bad

4. the same day at work I asked my body to help me up, what I was going to do is touse jumpers from his battery to my end and disconnect my battery just to check the alternator. I have told him stories that you do not want to disconnect battery from Benzs at all, as it might give more books to read :}}}. Well I had to step off for a sec. my body was at my car, and guess what hapenned ...... he disconnected the battery.. %&*^#$$%#
The only good thing out of it was that the NEGATIVE CONNECTOR WAS LOOSE ON THE BATTERY

4. Anyway I had nothing to lose, I put connector back on jumped to his car, started his car, let it run for 5 min min, shut down his car, disconnect jumpers, start mine no problem, voltage was about 12.3, which I guess enough to get you start the engine. My next step was to disconnec the negative end from the battery again (my body did it once already anyway .^%&$%&^#@), and if the car is still running that it means the alternator is working, well I disconnecter the negative end from the battery and ..........
........ CAR IS STILL ON, turned on lights, A/C, everything was working with battery DISCONNECTED.

Well it proved me that it was defective battery, which easy DIY (make sure use have some sort of power to the car while doing it) and for some reason it was not charging off my alternator even though it was working. My guess it is because this car have to much brains in it, and it sensed something wrong with the battery and was not giving it juice anymore.

Now the second problem, since the battery got disconnected I have got a message something like that: " elec. stability prog. not availb. ESP " . I was reading other posts where you have to turn wheels all the way to the right and that to the left, drive a bit, and so on the last thing was to empty the ash tray (russian joke). But I was reading one post where the guy found burned out fuse (#62) which was the problem (he also disconnected his battery :}}} ). Well I looked for that fuse ( fuse box under the hood C240 2001 W203) but it was fine, that I was checking the other ones , they all seemed fine. Well the only problem I was thinking of was rear SAM box ( I guess the other name for the FUSE box), as many had problems with it while doing any type of electrical job on the car.

But I was removing fuses with the engine runing (I was not thinking about while doing it as I was pissed off with my body who got me ESP message), when I got back to the car there was 9 foults on display, I was F%%%%, turned off the engine , turned it back and miracle NO FAULTS AT ALL. I do not know what cleared it, but I think while the car was runnig and I was removing fuses ( all clear ones under the hood) and putting them back one at a time, something got reset. Drove it around the coner - no faults

Mtu

Guys,

I'm going to be shipping my car overseas inside a 20ft container, but the shipping company told me they must disconect the battery and let it stay disconnected till it arrives at the destination country. Do I have any options in this case? or I should just cross my fingers and hope everything will be fine when I reconnect it back...

osyrus68

So here goes, reading this thread there are about 10 messages that actually relate to the topic. For DIY'ers and people looking for help, These forums are god sends, but not unless used properly, and not littered with junk (as 98% of all forums these days are). So if you had no problems replacing your Battery or just had the dealership do it, good for you, shut up and move along.
For those of us that are having difficulties, how about posting the error message and then detailed fix and yes RTFM does help to a very small degree, No manual that comes with the vehicle is really worth it's weight in salt.
SO with that said After changing/disconnecting battery for any reason here is
what is/has happened with me.

1: ESP fault - Not Available. Fixed by turning the steering wheel to the left until stop, then turning all the way right until stop. Turn off car. Restart. no more error message.
2: Sunroof would not operate - Fixed by following the manual. pressing the up button until it synched.
3: Power windows, same as sunroof.
4: Faulty display error message - HELP!!! still not fixed
5: Turn signal/windshield Wipers don't work - HELP!!! still not fixed
6: Key fob electronic door release - Does not work, have read posts, will try fix later.
7: Rear sunshade control - does not work HELP!!! still not fixed
8: Hazard light control - does not work
9: Reverse back up lights - do not work
10: Gas Gauge - not working HELP!!!

So I've read replacing the rear SAM...but that doesn't explain why some work and some don't. If the same was blown none would work. Any actual fixes that could be recommended for the above problems listed?

mleskovar

Wow, if all those things worked before you replaced the battery it could only be something you did. Reversed poles on battery? Popped one/some fuses? When disconnecting battery did you do negative pole first and reconnect in reverse order?

osyrus68

As I am not new to the world of working on my own car, (I've owned 4 vehicles and never taken them into a shop, even done a few engine swaps of course these were all pre 1990 american made vehicles) However I AM new to the world of MB's so...read the manual ,haynes manual too, looked on here, and a few other forums before removal/disconnecting the battery (the electrical/software stuff is not my forte thus reading instructions before hand) and followed the letter of the law. The Battery was also disconnected for more than 5 minutes...I was changing the fuel filter/ spark plugs/ spark plug wires/air filter...
I suppose my main question is,
I believe the faulty display warning to be connected to all these other things going wonky too. Am I correct in that? and is this something that just needs a "reset button" pressed or is this a reprogram from MB dealer/repair shop?

mleskovar

Disconnecting a battery should not cause problems other than the resetting of some of the features, which you've done. I've never heard of all your symptoms happening at once so I don't have an answer other than check fuses. It is possible you need a reprogram.

samaritrey

don't you have to reprogram the sam when you replace it?

efzauner

I got a used 2005 C240 with 50Kmiles in july.. .. lovely to drive. but OMG what are the german engineers smoking? this sort of problems should just never ever happen on modern electronics.
I hear all sorts of reliability issues with MB in these forums and I am praying I will not see them. I have a 2002 honda odessey with 120Kmiles on it with only a few minor glitches...
My feeling somehow is that the engineers on these cars are always trying to find ways to make things ever so complicated.

samaritrey

i am sure you will be fine not that many of us have had major issues with are cars. remember how many w203's are on the roads in the us. but remember no Honda is as nice as a w203 i would not be caught dead driving any Honda even a nsx.

efzauner

yes the c240 is nice and I enjoy it very mush.. but the honda Oddysey is hard to beat: It can seat 7, tow 4000lb, fit several 4ftx8ft sheets of lumber, cary 12 foot long 2x4s or larger, and even put a 7ft christmas tree inside and still cary a family of 5! No other car that I know of save the very very big SUVs can do that! It has a very smooth and powerfull V6 for which I can change all the fluids myself with standard brands and not have to go to MB!
I just feel that there is nothing special about the design of the engine or transmission or electronics on the MB that should require all of its prima dona care.

Scatterblak

This is incorrect. The rear sam components are fairly compartmentalized, and it's possible that a surge may damage the sam so that only portions of it are failing. A possible reason 'some work and some don't' is that some components may only partially fail after a surge, and simply won't perform to specifications, as opposed to not performing at all (Such as a diode leaking voltage after an overrun). This happens with computer systems all the time, and often leads to spurious errors that are very difficult to replicate and track down.

Bif powell

2002 C32 75k+ miles.

My battery has gone dead about 4 times because of passenger power seat module slow draw...did it several times before I figured out what it was, so maybe my battery just kind of screwed up from that?

When I fixed that problem, it runs and starts great all the time.

I stored it this Winter for about 3 months and the battery went dead dead dead. This battery is about 2 years old. I used a battery charger to charge up the battery and had a few 'click' failures and charged some more before finally getting it started. Drove it around some, commuted back and forth to work, ran errands, for 2 days all was fine BUT I never really felt like it had a full good charge through those 8 or so starts - normally it just clickvroooooooom but since getting it restarted it's clickruhrurhruhvrooooooom.

Yesterday I go to drive it, it starts fine, no warning lights, but down a block or so, it's obvious it won't shift out of first gear. I can't speed-shift and the w/s button does nothing. The car seemed/sounded/ran fine otherwise. I go back home, deal with it later, do some research. The car restarts fine, the check engine light is on now, it still won't shift out of first and power is reduced, so I'm in limp home mode, no?

Seems like low power in the battery could cause this kind of thing, but is my battery weak or does it just have a weak charge - does something need to be reset in any case? How can I test the alternator? Can I do more trouble-shooting/resetting myself? I am familiar with the car mechanically and have done repairs and mods, but will I need someone with a STAR system or something if I figure this out? If I got a new battery, will I still need to get someone to reset it and what specifically needs to be reset?

I charged it more with the charger, I think it was 12v, 10AMP position for about an hour, started it up and same problem. All other systems in the car seem fine and through all this it remembered by radio stations and power window/mirror/moon-roof never lost my preferences or needed to be cycled all to my surprise, as when it's died before I had the common problems - so maybe "dead dead dead" is exaggerating, but it appeared dead to me.

Any advice appreciated!

mleskovar

First get an OBDII tester to see why it's in limp home mode.There's several threads on this but basically to check the alternator measure across the battery terminals while running and the voltage should be >13.5. To check the battery charge use the following chart:

Charge Volts
100% 12.7
90% 12.5
80% 12.42
70% 12.32
60% 12.20
50% 12.06
40% 11.9
30% 11.75
20% 11.58
10% 11.31
0 10.5

efzauner

regular car batteries are not designed to be run down *dead dead dead*. if you do this more than a few times the battery will be dammaged... Only deep discharge battereies are designed to withstand being decharged completely.. So even though your battery may be only 2 years old it could no longer be in good shape.

230kDrew

I was outrageously bored and decided to see what this thread was all about, because I'm really into stereos and have disconnected my battery roughly 20 times installing new amps, running power wires to the trunk, etc... and was curious as to what issues others had run into doing something i had been doing for years now, starting when I was roughly 16... (my first paycheck after buying my car went entirely to a new stereo) and i have never had to replace anything because of disconnecting/reconnecting a battery. I read that a number of you have been disconnecting the battery the complete opposite of the way my grandfather (a 45+ year veteran ASE certified mechanic) had always taught me to. He always told me the positive should be disconnected first, because the way he explains it, the electricity (however low/dead your battery might be) is always traveling from positive to negative. Therefore it makes sense that one should shut the source wire, the positive, down first by disconnecting it, and let the last of the charge run through its course to the ground cable. You cant exactly blow anything without electricity, so if you take off the positive, you remove this from the realm of possibility. then when connecting the battery, to avoid burning anything out or frying your electronics, connect the negative then the positive, so that once the positive is connected, the electricity has somewhere to flow... into the ground. as i've said, i've personally disconnected my battery at least 20 times, and have never had to replace anything. I never even had to do the whole lock to lock reset. NEVER LEAVE THE KEY IN THE IGNITION WHEN CHANGING THE BATTERY. common sense, which sadly isn't common, dictates that one should not try and activate, or leave activated, anything electrical when disconnecting or reconnecting a battery as this is clearly the most effective way to burn your fuses out.

the only issue i have ever had, in any way, is the auto up-down window controls. simply holding them all up or all down for about 15 secs like other posts have stated has always worked for me, and this didn't require any other parts to be bought, replaced, or even reprogrammed.

hope this helps!

p.s. to the guy with the question of where his battery is... im not sure if anyone answered, posts blended into one after the first 3 pages, but its under the air filter. there are three clamps that simply unlock and the air filter will come right off exposing your battery. Good luck!

mleskovar

It's recommended by MB. Here's my understanding to why: Capacitors hold a charge and can discharge even with the battery disconnected. Think of them as mini batteries. Without a ground the capacitors have no path to discharge. With today's micro circuits a capacitor (or even static electricity) can blow a circuit. Which is what has happened to many people on this board. The SAM modules are extremely susceptible to this problem. Make sense now?

230kDrew

Ehh, no disrespect for MB, obviously I love them enough to drive one... but I have to disagree. I never pretended to be an expert, or even know anything specific about electronics, but I do know that in my real life experience, which I always have valued above the words in a book, Black Red Red Black has always worked and never has it cost me a cent. a few of the posts on here are from people who did as MB suggested and it still cost them a new SAM mod. plus, once you do connect the new battery, and the ground wire, the electricity stored in the circuit from when you didn't allow it to leave through the ground whilst disconnecting the battery, will suddenly have a great path to discharge, right into your car. Just saying, this sounds like a much more dangerous idea.

havoc_vulture

does the radio go out and need a code after you disconnect the battery??