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C320 battery problem **HELP**

7K views 20 replies 16 participants last post by  Mercedes Benz of Florida 
#1 ·
I own a 2002 C320 Mercedes. Recently, I've been running into some problems with my car. Few weeks ago, my car wouldn't start all of a sudden. I jump started and I noticed 2 faults .. ESP warning light and light sensor problem. I thought it was the battery so I replaced the battery at SEARS. I came back from a week vacation and the car wouldn't start again. I noticed the same warning lights when I did jump start. Can somebody please tell me whats wrong with my car or if anyone has run into similiar problems. Thank you very much in advance and I would appreciate any feedbacks.
 
#3 ·
Welcome to the W203 forum. What you have is a very common problem, most common in the '02 C320. It's the power seat module going bezerk and will drain your battery dead. To double check, charge up the battery, disconnect the harness under each front seat and see if the battery drains. Plug one in at a time to see which one is causing the problem but you can probably just put a meter on the battery and see if pluging it in causes a drain. If that's the case, it's simple, just plug the seat in when you need to change it and then unplug it OR get it fixed, you'll need a new power seat module and usually if one goes, the other isn't far behind.
 
#4 ·
Thanks for the advice ...

Thanks for the advice. Just wanted to mention also that I had neon lights installed under the dashboard. I got it connected using the connection to the cigarette lighter. Do you think perhaps this might be causing the problem? I rarely turn those lights on. Thanks.
 
#5 ·
i've installed neons in many cars for shows...if you want to limit battery consumption and give full power to your neons, just run your power through a relay with a constant off the battery....just for info the cigarette lighter is on through accessory, so everytime you lock unlock it sends power to your lights.... When you jumpstart or change the battery those warning lights come on. After you start, turn the wheel all the way to the left, then all the way to the right. It should reset.
 
#7 ·
xbenzx said:
Thanks for the advice. Just wanted to mention also that I had neon lights installed under the dashboard. I got it connected using the connection to the cigarette lighter. Do you think perhaps this might be causing the problem? I rarely turn those lights on. Thanks.
Same deal as the seats, disconnect the neon and see if the battery stop draining.
 
#8 ·
Same '02 320 Seat Issue

I had the same issue with my seat, but I haven't had it fixed yet. I purchased a new battery over the summer, thinking that was the problem, but after leaving my car to sit any time over 24 hours my battery would die. Then it became an 8 hour issue. I had to ride around with a jump box in my trunk, thinking the alternator was failing:crybaby2: ... Well, to make a long story short, I disconnected the seats and my battery seems stronger than ever:D Does anyone know how the cost of having a seat module replaced?:(
 
#9 ·
I have had my car since 03. It is a 01. It has been in the shop several times this year for the same exact issue. I have had people jump my car, and have had to take a jump box with me while on the road. I was told that it was the seat control modules, I have had them both replaced which I have paid over 2k. Guess what? This did not resolve the issue. I which you luck on this journey as it is a well known issue but with no solutions.
 
#10 · (Edited)
Same Problem

Me too, I replaced the new battery and couldn't stop the draining. And the shop found out that it's the seat modules. However, I had no problem for about 1 year after changing both seat modules, and just last week, the problem came again and the shop checked for me and saying that this time is not b/c of the seat module. He couldn't find out why and asking me to go back to MB and have them to figure out. Anyone have good advise? thanks!!! and by the way, I am living in northwest suburb of chicago area, does anyone know any good MB dealer around my area? I don't like that hoffman estate MB dealer b/c they seems linked to MOTORWERKS. thanks!!
 
#12 ·
Chocolatdee said:
I had the same issue with my seat, but I haven't had it fixed yet. Does anyone know how the cost of having a seat module replaced?:(
I replaced the driver side in my 01' C320 - part cost $260, took me about 15 minutes to switch it out. Dealer wanted $680!!! WTF? Passenger side went out a few months back so I just unplugged it. It would be nice if we can find enough people to file a class action lawsuit against MB since they claim it is not a manufacturing defect, but it's a very common problem with the seat modules.
 
#13 ·
I recently became a memeber of the "C320 Battery Drain Club." :p I charged the battery and disconnected the seat modules and so far so good. Many praises to this site for the info!!!

Perhaps I'm not understanding something though ---> IF there's a PROBLEM with these seat modules allegedly not going into "sleep" mode THEN WHY PAY (parts & labor) TO HAVE ANOTHER EVENTUALLY-DEFECTIVE COMPONENT put into your car?????? Until MB decides to FIX it, aren't "we" just wasting time and money? ... AND setting ourselves up for the SAME problem in the future?

Does anyone know if MB HAS fixed the seat modules? ... or done a recall???

Lastly, I read on this site that the TeleAid could also be a drain source. If this is true, would someone please tell me how I can disconnect the TeleAid?

Thanks in advance for any/all help! :D
Jurgen
 
#14 ·
a similiar type of problem battery related

I also have a similiar type of problem, but I have a c240 the problem is that i replaced my battery and now i have an error on the display that reads the battery is defective does any one know what is happening or how to take that off?
 
#15 ·
JurgenB said:
I recently became a memeber of the "C320 Battery Drain Club." :p I charged the battery and disconnected the seat modules and so far so good. Many praises to this site for the info!!!

Perhaps I'm not understanding something though ---> IF there's a PROBLEM with these seat modules allegedly not going into "sleep" mode THEN WHY PAY (parts & labor) TO HAVE ANOTHER EVENTUALLY-DEFECTIVE COMPONENT put into your car?????? Until MB decides to FIX it, aren't "we" just wasting time and money? ... AND setting ourselves up for the SAME problem in the future?

Does anyone know if MB HAS fixed the seat modules? ... or done a recall???

Lastly, I read on this site that the TeleAid could also be a drain source. If this is true, would someone please tell me how I can disconnect the TeleAid?

Thanks in advance for any/all help! :D
Jurgen
...3 days after disconnecting both seat modules, CAR WILL NOT START - AGAIN! I have attempted to fully charge the battery overnight since I do NOT believe it is the battery. I still have to check the alternator. Based on what I've read here, I should probably also disconnect the TeleAid.

WOULD SOMEONE PLEASE TELL ME HOW TO DISCONNECT THE TELEAID?

SOMEONE MENTIONED THEY DID "SERVICE B" THEMSELVES. WOULD SOMEONE PLEASE TELL ME HOW TO DO SERVICE B MYSELF?

I REALLY NEED HELP. I RECENTLY BECAME DISABLED DUE TO A HOSPITAL-ACQUIRED (STAPH) INFECTION [HAI] THAT "ATE MY KNEE AWAY" -- result of a "simple" arthroscopy to "fix" an extremely minor tennis injury! ... long story short, I have lost my business of nine years; I have not been able to work for 4+ years; I am on disability; and I simply do not have $500 for an oil change!!! Irrelevant, I know ... I just really need some help with these problems. :((

PLEASE HELP ME!!!

Thank You All,
Jurgen
 
#16 ·
Battery Drain / Seat Control Module

JurgenB said:
I recently became a memeber of the "C320 Battery Drain Club." :p I charged the battery and disconnected the seat modules and so far so good. Many praises to this site for the info!!!

Perhaps I'm not understanding something though ---> IF there's a PROBLEM with these seat modules allegedly not going into "sleep" mode THEN WHY PAY (parts & labor) TO HAVE ANOTHER EVENTUALLY-DEFECTIVE COMPONENT put into your car?????? Until MB decides to FIX it, aren't "we" just wasting time and money? ... AND setting ourselves up for the SAME problem in the future?

Does anyone know if MB HAS fixed the seat modules? ... or done a recall???

Lastly, I read on this site that the TeleAid could also be a drain source. If this is true, would someone please tell me how I can disconnect the TeleAid?

Thanks in advance for any/all help! :D
Jurgen
I am having the same problem, and MB wants $1155.00 plus $255 for a new battery. My car is sitting in the garage and I can't start it, unplugged modules as advised but car still won't start, do I have to jump start it first? And seriously people, we need to get MB to fix this problem for free
 
#17 ·
PROBLEM SOLVED - REPLACED BATTERY

Hi weekendgangsta,

I went through the process of disconnecting the seats ... etc. etc. etc. ... troubleshooting for about a week. Using a portable battery charger, I recharged the battery overnight (with the seats disconnected). It took about 8 consecutive tries (key turns) before the car started -- but it started! However, it wouldn't hold the charge. I let the car sit overnight and it would not start the next day.

Then, after reading (here) about the approximate life of the battery (about 3 years), I decided to replace it with a non-benz ~$70+ battery -- before spending $thousands at the dealer on new seat controllers, etc. etc. etc.!!! What did I have to lose?

I HAVEN'T HAD A PROBLEM SINCE REPLACING THE BATTERY!
**AND** I HAVE RECONNECTED THE SEAT CONTROLLERS!

I hope you only need a new battery!

Best of Luck,
JurgenB
 
#18 ·
"When you jumpstart or change the battery those warning lights come on. After you start, turn the wheel all the way to the left, then all the way to the right. It should reset."

After changing the battery, initially I did get a bunch of warning messages.... BUT, they just went away! I didn't have to do anything....
 
#19 ·
Hey guys, had the same problem disconnecting the modules workes but you deff have to have a fresh or recharged battery to start the car.
You can eliminate which module is bad by disconnecting one at a time and seeing either the voltage drop or by trying to start the car.
I have a driver's side module brand new that i would like to sell. PM if you are interested
http://www.benzworld.org/forums/w203-c-class/1336015-w203-drivers-seat-module-sale.html
 
#20 · (Edited)
Hello All,

This is my first post and I'd like to use it to try to help my sister with this problem. She has a 2001 C320 Sport, with about 125,000 miles. Last year, she had to replace the passenger seat module. This month she had to replace the driver seat module. The MB service technician let her know, off the record, that the next thing that would probably begin to drain the battery will be the moonroof module.

Does anyone know how to disconnect the moonroof module? Can this be done?

The service technician also let her know that MB won't recall the 2001 and 2002 models with this problem because it's not a safety-related problem, and he advised her to buy another car. If she should buy another Mercedes Benz, he suggested that she not keep it more than 4 years. (His opinion based on the quality issues he has seen).

Thanks in advance for any suggestions!
 
#21 ·
Geez oh Pete! Man you guys got me spooked now!
Before I left for Overseas Duty; I did a lot of prep. work on my MB
I won't bore you with the details but I know about the friggin' battery
problem so I bought a Solar Powered Battery Charger.
I hooked it up to my Kompressor and made sure the SPBC was facing due East, where the Sun would give it a good dose every day!

I am due to arrive back in the USA in two days and after reading this
I am antsy. Dang it yall I hope it worked. MB is in a secured compound and no one is allowed to touch the cars in there so what's a soldier to do eh?

Hey; I'll let you all know in a few days ok?
 
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