rshoemaker

I've been experiencing some weird electrical issues with my car - some have been happening longer than others. I'll list them in the order I noticed them.

The passenger side seat switch rarely does what you tell it to do. Frequently I need to move the seat forward as far as possible and tip it all the way forward so I can load cargo. However, when I hit the slide forward and tilt forward buttons, the seat slides backwards and tilts backwards. Usually if I fidgit with the buttons, I can find a sweet spot that makes the seat move/slide forward. This has been happening for a while - maybe a year or so.

When I lock the car, the lights flash 3 times. This might be poor attention to detail, but I'm pretty sure it used to only flash twice. I can't find anything in the manual or online that explains what 3 flashes means. Probably not an electrical problem per se, but I'm curious if it means something. This has also been happening for a long time.

One of the key fobs stopped working last month. It started acting funny about a week before I was stranded. It stopped locking the car no matter what I tried. I thought that the batteries might be dying in the key, but it didn't ever have trouble unlocking the car so I didn't bother changing them. I found that if I put the keys back in the ignition, the ignition would click / unlock, then if I pulled the keys and shut the door the lock button would work. Finally, the key stopped working altogether. I was leaving work one night, I hit the unlock button and the car unlocked. I put it in the ignition and it clicked / unlocked. I turned the key and the car started, but then stalled immediately. I removed the key and put it back in the car, but the ignition wouldn't unlock and I couldn't turn the key at all. My wife brought the backup key and it worked fine. I tried swapping the batteries to see if that was the issue, but nothing I've tried has fixed the key. We've had no issues at all with the backup key for a month now. I've read that the keys have a 100k start limit on the rolling security code - not sure if that's true or not.

As part of diagnosing the issue with the key, I followed a troubleshooting guide that suggested disconnecting the batter for 20min. That's didn't seem to help at all, but immediately after....

...the window switches seemed to stop working correctly. I doubt disconnecting the battery would have that effect, but they really seemed to stop working properly right after. The switches have two detents in each direction: manual up, auto up, manual down, auto down. The manual detents work correctly, but none of the automatic ones work at all. If I push the rocker buttons all the way to auto open or auto close, the windows stop and nothing happens. All 4 window buttons behave the same way.

Then today I noticed a similar problem with my sun roof. The four way rocker switch has 4 detents: slide open, slide closed, tip up, tip closed. The first three seem to work fine, but tip closed doesn't. If I tip the roof open, the only way to get it to close is move the switch to the slide open position which causes the window to tip closed first and then I release the switch when I think the window is closed.

I suppose it is possible that none of this is related to disconnecting the battery, but I'm wondering if there's something simple that needs to be reset or perhaps a fuse blew. I doubt it's a fuse - in that case I would expect things to simply not work at all rather than work incorrectly. It wouldn't make sense for any of these issues to pop up after disconnecting the battery, but I'm at a loss trying to diagnose the problem(s).

Any suggestions?

n2it

There are others on this board which can certainly tackle some of these issues much better than I but as far as disconnecting your battery and the power windows and sunroof not working correctly now; you have to resync them after disconnecting the battery. In fact, that could also be the issue with your seat (but I doubt it). You can find the resynching instructions on this board by performing a search (my apologies, I would post a link for you but am running short on time). The instructions are also in your owners manual. Hope this helps some...

CKonstantin

As for resyncing your windows and sunroof
http://www.benzworld.org/forums/w210...cronizing.html

I believe it's in the manual as well, as for your seat most likely culprit is the switch it-self, if you're quiet handy you can try taking it apart and fixing it look here
http://www.benzworld.org/forums/w210...t-problem.html

But as you describe it it's probably the micro-switches themselves which are toast.

Best of luck.

n2it

From the same thread...a pdf file on repairing the seat module. Very helpful: http://www.benzworld.org/forums/atta...tch-module.pdf

rshoemaker

Awesome! I'm going to try resynchronizing everything in the morning...

This has to be the problem - I also saw the BAS/ESP error the first time I started the car after disconnecting the battery, but haven't seen it since.

rshoemaker

Thanks, this cleared up the issues with the window switches. The headrests and BAS/ESP didn't need to be reset for some reason.

Perhaps I'll tackle resoldering the circuit board for the seat switch when it warms up a bit.

Any thoughts on why one of my keys is completely useless? The little led on the side of the key flashes when I hit the button and I put fresh batteries in it, but it otherwise won't work at all.

Also, is 3 flashes normal when you lock the car or am I crazy?

Thanks again for the speedy response!

renault12ts

Correct, resyncing is necessary. So many people discover this after the battery is disconnected.