Issue with windows/mirrors
 

Hey guys, I got a 2007 4.8 x5
I've been having issues with my windows. Randomly the window switches stopped working (3 windows - both rear and driver side) Passenger window goes up and down no problem with the side switch. Master switch doesn't seem to work at all (changing mirrors placement doesn't work) I'm not exactly sure why. I checked fuses that I could find and they look ok (tested with multimeter - I didn't pull them out)
I unplugged the negative cable from the battery and still same issue. Any ideas where to look?

You might want to figure out how to connect a coding cable to your car and look for error codes from modules.

I believe there is a door control module in the driver door...not sure.

I'll check with my bmwhat app and post back. I believe there was a Lin communication error but I wasn't sure what it was. I'll post back.

This is the error I got from bmwhat

LIN bus is the communication channel between the master window switch,mirrors and the Footwell module(FRM).

"Fussraum modul" is foot rest module. As is "FRM"

E70

Of course if you cant read russian, it might not be much use. ;) try google translate

So what exactly am I looking for? Module? Loose connection? Also if you can point me where to look that would help me greatly.

If the lights and other stuff work correctly the problem probably is not in the FRM. You want to disconnect the mirrors and the master window switch and clear then check the codes again. If the LIN bus code is gone you can start connecting them one by one and check the codes to see when the LIN bus problem will reappear. My best guess is for the master switch faulty, so you try disconnecting it first and check the codes.

^ There is a little 'scale' icon in each post. This is a way of voting for a user/post.

So when I clicked on bawareca's it said "You need to spread some reputation around before giving it to bawareca again"...

:thumbup:

:thumbup:
I like to give reputation too ;)

Same with me. There are a few others like that for me, too.

Ok so I had a chance to take it out and yes you were right. Master switch is f***ed. Here's a couple pics. Any idea if I could just get the burnt components? I can do soldering work.
http://imageshack.com/a/img538/3576/AQZzTm.jpg
http://imageshack.com/a/img911/78/nRxicE.jpg
I found this one that is in better shape for reference
http://imageshack.com/a/img832/2312/img30381s.jpg

Impossible to say which are bad. Impossible to know what components to buy. Most have no part number nor values on them.

Isnt this a simple $150 part? just buy a new one.

Maybe might be easier but if I can save myself $150 why not. I checked the components they actually seem ok just the lines are totay burnt. I'll see if I can repair the board and post back. Worst case scenario I need a new switch. Best case I fixed it for free. I work with cell phones and do board repairs so maybe its paid off. We'll see I guess.

Cool.

Usually people that can do this kind of repair dont ask 'can it be done'. ;)

Worse case is you burn out something else on the bus.

I have a switch from my flooded parts car. It was under salt water for sure, but the elements may have survived. I can try to find it if you are interested.

Swap the switch with used or new one, its not an expensive part in the grand scheme of things.

Oh yes that would be great if you can find it and post pictures of the board... I actually fixed it, it worked for a little bit but when pressing my window down (driver side) I think i reshorted the line and I blew it up again.. LOL
I'll retry to repair it again tomorrow while I'm at work... if anyone is curious heres a picture of the current repair (blown again though)
https://imagizer.imageshack.us/v2/53...909/Eo7UtG.jpg - blown line
https://imagizer.imageshack.us/v2/53...537/ft2R8Y.jpg - From this image it's hard to see it unless under the right light but I got a small copper wire running under all that burn crap LOL

Success!
I ended up repairing the board. It was such a mess everything was shorted with ground. I had to use isolated wire I had from a macbook air display cable. soldered everything together and tested with my multimeter - no more short. Plugged it in and everything works. doesn't look pretty but it works (and gets covered by plastics anyways) The line was so badly burnt that I could actually fit the wire in it with no problems. I glued it down with some acrylic compound for boards and everything worked out great.. Sorry I forgot to take pics.

Interesting. Any idea what failed initially to cause this? A trace partially fail, and then the remaining trace overheated and burned due to the increased current concentration???

I'm going to guess that some water got in it and caused a short. The line you see with the white stuff on it (from the rubber mat with the buttons) melted right on the line. That line was completely shorted. I scratched it a lot and cleaned it and tested with multimeter - still shorted with ground. Had to bypass it all with isolated wire that I used from a macbook air lcd cable. Same thing on the other side (which connects to that line)