Battery Drain C200 Kompressor

[NZNobby]

Will be grateful for any suggestions people can offer.

I am the proud owner of Dec 2001 C200 Kompressor (first registered Dec 2002) 40,000KM recently imported into NZ from Singapore. Delighted with car but have a battery draining problem.
Replaced battery soon after arrival because it could not hold a charge. New battery went flat after a week without use. After reading comments in this forum I have carried out the ammeter tests which showed a battery drain of 1.1amp with all things I could turn off, off.
Then I went through the fuse by fuse removal test and after much head scratching, trial and error, and I hope, logical thinking have the following scenario.

With all systems off and the 1.1amp drainage showing on the ammeter. removing fuse 27 ( used in the seat and steering wheel adjustment circuits) and waiting 4/5 seconds the ammeter reading reduced to .09amp i.e. virtually 0. Fuse 27 was then replaced but did not cause the drainage to immediately reappear. Inserting the key and turning to position 1 ( not starting the engine) and turning on parklights or opening the boot (boot light comes on) or starting the car and then testing the 1.1amps drainage has reappeared. It seems that any significant battery draw sets up a situation that leaves a drainage on the battery that is not turned off when the car is turned off but the removal of fuse 27 will turn it off……..

Any ideas please..

Regards

 

[jberks]

Well done on getting this far.
It will be a control unit but which is beyond my knowledge. I assume the seat control one but I'll leave this for more specialised folk.
We had the same on an E class. Turned out to be the dashboard switch cluster and it didn't begin to drain until 15 minutes after switch off so it was a nightmare to find! Funny things mercs!

 

[Ellsy Tanners]

J berks is right, it will be one of the seat control modules, disconnect one by one, driver then passenger. unplug the main connector block under the seat, attached to the seat base.

Beware of any small yellow connector for the airbag system. dont unplug them as this could put the srs light on.

 

[NZNobby]

Tks ET & jb. To clarify...unplugging the main connector block under the seat is "disconnecting the control module" for that seat.

 

[Ellsy Tanners]

Yes thats right

 

[EagleI]

I had a similar problem on my C220 CDI. Battery drained after 3-4 days of standing still. The door and seat modules had been eleminated, and so was the boot light. In the end I ended up taking it to MB and the problem was diognised to a fault with the mobile phone control unit.

I got it changed by MB so that I could hold them to account if the problem still remained. Total cost £800 !!!! Ouch !

I had my mobile phone as a factory fitted option. I am no techie but Hope this helps !

 

[NZNobby]

Tks for that EagleI. Thank goodness I don't have a mobile phone to worry about. Good luck. Regards

 

[NZNobby]

Try this for my result in using this solution..
http://www.benzworld.org/forums/w203-c-class/1403233-diy-how-fix-your-power-seat-2.html

 

[television]

This is interesting and I think the the memory is retained because of the fault in the module,, If the module is OK say passenger seat done at the same time then the memory may not work for that seat.

A very good solution though and we should have it in our DIY section. Do you feel like giving us the pictures