List of faults that occur after disconnecting battery...

[ggantt]

do you know where the battery is located on a 2001 c-240 six speed manual? left lights and the battery is dead. what's the mfg's recommended procedure on removing and replacing the battery? I've heard a lot of horror stories that have me very tenative to tackle the task myself. I'm tempted to let her roll down a hill and pop the clutch. I've heard the rear fusebox and possibly the the front fusebox can be killed when the new battery is hooked up. Can you help me with the recommended procedure?

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[ggantt]

Whew! I'm trying to avoid this scenario. I haven't touched my c240 since the battery died. unhook the negative before the positive? where is the darn battery located. please help

[ggantt]

Originally Posted by anakin14

Don't ever run your car without the battery installed. Your battery acts as an electicity dump and your car's electrical system dumps any unused current into the battery. When your car needs more juice than your alternator can supply, it draws the extra current from your battery....your car doesn't only use the battery when starting up!

2001 c240 six speed. I left lights on and the battery is dead. What should I do to keep my cost down to get it running again. Can I just let it roll down the hill and pop the clutch or what?

[ggantt]

Originally Posted by MB-BOB

I did a search for a member to run down some answers to specific faults that occurred when a repair station disconnected his battery to work on his car. I found in the search that there are a variety of faults... no real pattern to report.

Everyone who keeps their car long enough will eventually have to disconnect an old battery to replace it with a new one. Given the emergency nature of dead batteries when you least expect it, a dealer with expertise may not always be handy, either. So, it would probably help to identify what can happen, and the fixes you have found to correct them.

If we get enough responses to these, I will make this a sticky thread so all of us can find it in the future. So please share your experiences here. Thanks.

what's the correct procedure to avoid all these things? It sounds like changing the battery in a mercedes is very complicated. Is there a way to remove/change the battery without any additional cost other that the battery?

[ggantt]

Originally Posted by HoustonC230

Needing to re-synch the windows/pano roof is normal (instructions in the manual). I've disconnected my battery countless times, never had a problem with the rear-sam.

I always disconnect the negative first though, as you should for any car. Not sure how this would affect the rear-sam, but for $320, I'd say it's something you don't want to chance!

thanks for putting things in perspective! I left my lights on and the battery died. I read all the possibilities of what could go wrong when I jumped or changed the battery I grounded first, then applied the positive contact in the designated contact area and the car runs normally and all the electronics appear to be functioning fine. I had to resync the standard items ofcourse and the ESP reset after a couple of restarts. whew!!

[Jorel C320]

So whats the secret to replacing a battery without messing everything up?

[des]

did you find anything out after receiving all the faults. we disconnected the battery and received the same faults, trunk not open, gas gauge doesn't work, etc. we had just replaced the whole fuel pump w/sending unit and the check engine light was on so he thought if he disconnected the battery it would reset everything. we have changed the battery on it before and
the only problems was just the moon roof resyncing. any help

Originally Posted by gmzc320

Hello to everyone, I have a 2001 c320 with 60k miles, and everything seems to be working very well, but in some workshop they disconnect the battery to removed it from its place, so when they reconnected and start the engine, some faults came out in the MFD

ESP not available, but this one came off a few minutes before
Display Faulty, the gas gage doesn’t work
The trunk won’t open
And the fuel filler flap doesn’t lock.

Some people think that maybe problems with the computer and need to be reset, y really don’t know what to do, and I also don’t have a MB dealer near my city, I appreciate any help if any of you know about this problem.

[des]

did you find out what needed to be done to fix this problem. we just replaced the fuel pump/w sending unit and everything was working fine but the check engine light was on so we disconnected the negative side battery and reconnected and then we received all the faults in the display and the fuel gauge didn't work. we have replaced the battery before but the only problems encountered were the sunroof resyncing

[Jorel C320]

So i called roadside assitance...the battery was $154, so they told me to just buy it at an autoparts store. Bought the battery for $99 with core charge and tax. MB changed the battery free of charge...gave him a 10$ tip. Gonna return the old battery to get my $12 core charge back.

All in all...$97 bucks to change the battery and to make sure everythign is running good.

[mleskovar]

Originally Posted by Jorel C320

...they told me to just buy it at an autoparts store. Bought the battery for $99 .

I bet you didn't buy a 100 ah battery....which is the correct replacement. If it was 100 ah...who makes it?

[Jorel C320]

Originally Posted by mleskovar

I bet you didn't buy a 100 ah battery....which is the correct replacement. If it was 100 ah...who makes it?

no idea...i just bought the one autozone said it was..and the MB guy that installed it said thats the right one aswell. Its from Duralast.

[atc9443]

I'm having the same battery drain problem, brand new battery got replaced...I did all the re-syncing of the electricals that was needed to be done, but still, a week later car would not start due to battery. The only thing I notice now is that the comand unit's fan still runs after car is shut off, and i think that is the cause of the drain...I also noticed that the when the comand unit is on the red led does not come on any more...does anyone have any inputs to this situation? The damn stealership wants $3900.00 to replace the unit. They are crazy.

[ducatimotor]

Originally Posted by atc9443

I'm having the same battery drain problem, brand new battery got replaced...I did all the re-syncing of the electricals that was needed to be done, but still, a week later car would not start due to battery. The only thing I notice now is that the comand unit's fan still runs after car is shut off, and i think that is the cause of the drain...I also noticed that the when the comand unit is on the red led does not come on any more...does anyone have any inputs to this situation? The damn stealership wants $3900.00 to replace the unit. They are crazy.

I have exactly the same problem. If I leave the car idle for more than 3 days the battery runs off, while the fan is always running...

[Roach]

I recentlt had to charge my battery and I took it off by pulling the positive first and poputting it on last. After though my instrument lighting seemed dim now I think it's getting dimmer. If not it's just so dim that I keep forgetting how bad it is until night time. Has anyone else come across this?

[tivoboy]

I'm having a battery problem, car won't start, but when I jump it, it starts fine. But then, about 1 hour later, it won't start again. Is there a list/process of how to change out the battery? I don't want to have to jump it and head to MB for repair, they will probably want 250$+

This is a W203 C320, there HAS to be a fairly simple way to swap a battery

[mleskovar]

Make sure key is not in ignition and remove negative terminal before positive terminal. There's a sticky on how/what to resynch with new battery.

[vadim]

Originally Posted by tivoboy

I'm having a battery problem, car won't start, but when I jump it, it starts fine. But then, about 1 hour later, it won't start again. Is there a list/process of how to change out the battery? I don't want to have to jump it and head to MB for repair, they will probably want 250$+

This is a W203 C320, there HAS to be a fairly simple way to swap a battery

Call Roadside Assistance - they will come to your door and swap the battery if your problem is the battery itself, which they will also dignose. You will only pay for the new battery if yours is busted.

[tivoboy]

Thanks, I got the car going. Actually, DIDn'T buy the battery at napa, since it was like 1200cAmps, since that was so much over spec, I went to MB. They wanted 180$ for the MB battery, only 2 year warranty on it, but he hooked me up for 150$, about 30 more than the napa battery.

But, there was a problem getting the bracket off. I didn't have a 13 inch socket wrench EXTENDER to get down in the bay, on the side of this massive battery to unscrew the one bracket screw. so, I call roadside, they came, pulled the battery, put in the new one, took the old one, no charge. I tipped him though, seemed happy enough.

Nice to know, that they will come for the LIFETIME of the vehicle and jump, or replace and charged for the battery, totally free.

[Boom vang]

Disconnected my battery to install a new steering wheel.

No issues what so ever other than: my stations on my radio had to be re-programmed and the trip computer was reset back to 0 for both current and history.

[guanabara]

Originally Posted by k_lundquist

Someone care to weigh in on this? Seems like a BAD Idea to me. Don't know a whole lot of indepth information on Mercedes, but just common car logic would suggest that disconnecting the battery while the car is running would tell the alternator that the battery is dead (not missing) and the alternator would start driving power to charge it. Which would be a ton of AMPs and a shocking experience.

THis is a very DUM idea. You will definetely damage lots of things as the battery acts as a huge capacitor and voltage limiter. Without it you would have an overvoltage condition and lots of high spikes. The regulator is most likely not designed to take the role the battery has and so it will not be able to protect all the electrical components.

I don't know why people not only choose not to read the manual, but worst yet, come up with uneducated dangerous ideas.

I have disconnected the battery on my E320 and C230 several times. when In needed to replace them or doing works that I wanted to make sure no pwer source was present.

Comon sense prevails, of course make sure the ignition key is not on whe you are connecting/disconnecting the battery, as you will cause transients to go to all powered components when connecting and disconnecing it.

Resetting the things after th battery is reconnected is actually fun, like teaching a robot to walk. It is not a failure, but a way to manually teach the electronics what the full range of operation of things are. This is done mostly for safety, I am sure.

In regards to placing a battery in parallel (in case you think re-teaching the car is not fun), definetely again, if you have no clue what you are doing then you should never be doing it. If you place a 9 V or lower voltage battey in parallel with your car battery and the car battery voltage is higher you will cause a surge current into the battery you are connecting in parallel and may overheat / damage it in a short few sec and even hurt yourself or do some damage, unless proper isolation diodes are placed in series with it . (If you don't know what it is don't ask , you should not be doing this job anyways).

So in summary, contrary to some theories, the cars electronics are not designed to self desintegrate if common sense and some manual reading is done, prior to connecting/disconnecting the battery.

BTW, I never had any ESP alarm after connecting a battery back.

Incidentally if you close the trunk after taking out the battery, be aware that you will need the metalic key to open it again by turning the cilinder a quarter turn counter-clockwise (CCW or left in lay terms) and then push the cilinder in.

[guanabara]

Another very important thing a lot of you guys seem to be forgetting too and that is the free assistance MB provides for stranded situations such as bad battery or discharged battery.

They will come to your house jump the car up, or even replace the battery at the normal retail price with no installation charge at all. No other car company I know would do that. So go on enjoy the day,.

[wuufer001]

Originally Posted by guanabara

Another very important thing a lot of you guys seem to be forgetting too and that is the free assistance MB provides for stranded situations such as bad battery or discharged battery.

They will come to your house jump the car up, or even replace the battery at the normal retail price with no installation charge at all. No other car company I know would do that. So go on enjoy the day,.

even with the warranty passed?
well this is my first problem with the battery.
my batt totally died so i am thinking of what i should do. will i be able to jump start it without any faults?
because last time i my dads s-class was jump started then the seat buttons was faulty. i called a dealer today asking whether i will get any fault codes if i jump started but they said no. i now i'm
the reason i can use any of the chargers are because my car is parked in an apartment garage and the garage doesn't have any outlets so there is no way for me to use a charger.

[ezncik15]

I replaced my rear sam after frying it when i tried to replace my battery myself. After replacing it the fuel guage display still doesnt work. Any advice?

[06c230hwd]

as far as jump starting goes, take the chance if you want too. i tend to do what the book says, the manual says NO to jump starts, period. i can't imagine that simply changing a battery in the car would cause the rearSAM to go bad... wouldn't you have to reverse the polarity or drop a wrench across both terminals?

anyways, just go buy a battery from an auto parts store and DIY (its either a group 47 or 49). very simple procedure. don't be prude just because it's a "MB"!

[06c230hwd]

Originally Posted by wuufer001

even with the warranty passed?
well this is my first problem with the battery.
my batt totally died so i am thinking of what i should do. will i be able to jump start it without any faults?
because last time i my dads s-class was jump started then the seat buttons was faulty. i called a dealer today asking whether i will get any fault codes if i jump started but they said no. i now i'm
the reason i can use any of the chargers are because my car is parked in an apartment garage and the garage doesn't have any outlets so there is no way for me to use a charger.

go to parking garage. take your actual key out of the key fob. place it in the door of your car. open door. pop hood. uninstall battery. go home. charge battery @ 10 amps for 2 - 3 hours. go back to car. install battery. drive away. (assuming you dont have a dead cell)