[Johnes]

Hi,
I picked up my car with this issue:
The driver's window switch mostly doesn't work at all. Intermittently, it's possible to roll the window down, but only an inch or so and then it's stuck there. The next day or in a couple of hours it's possible to roll it back up.
The previous owner had it diagnosed by a "non-BMW" technician as faulty FRM module. His reasoning behind it was that if the window motor is powered separately, it works all the way up and down now issues.
All of the other windows work.
I found this thread:
https://www.e90post.com/forums/showthread.php?t=695268
Which talks about faulty capacitors. I pulled my switch unit out and took it apart. Didn't see anything wrong, but when I tried to charge the capacitors with a 9V battery and after measure the voltage the largest capacitor didn't hold anything. The two smaller ones did. I'm not an electrician, so I'm not sure if it's possible to test the capacitors without soldering them of the board.
I would prefer to try to replace the capacitors over buying the whole switch unit. Especially since I'm not sure if it's faulty.

Does anybody have a similar issue? I talked to one place in Vancouver which does FRM modules repairs and I have been told that my issue is most likely not caused by FRM module.

I would appreciate any help on this problem.
Thank you.

[Johnes]

[Johnes]

Here is a little update:
Right before I almost ordered the capacitors, I tried to roll down all the windows with the key fob. And the driver's window got stuck the same as always (2inches down or so). Then I tried to roll all the windows up with the key in the door and all the windows but the driver's window went up. The next day, I was able to roll the window up and tested the same with the window controls cluster removed to prove that the issue isn't in it; It behaved the same as always.
After a couple of rainy days, I found that there's a leak into the cabin through the driver's door vapor barrier. Since I had to take the door apart, I decided to test the motor and the actuator. With external 12V, everything worked perfectly. I was hoping that the issue would be in a loose or broken wire connecting the door and FRM. I unplugged it and tried to bend it etc. No change. When the window is stuck and doesn't respond, there is not measurable voltage at the motor connector. I was too scared to measure it at the door connection due to the small space and not having small enough alligator leads.
I had just two hours to work on it, I decided to unplug the window motor to prevent accidentally opening the window in the winter and getting it stuck there.
The interesting thing is that now with the disconnected motor I hear the relay clicking when I push the window button. It will react (click) only three times. After that, there is no clicking when pushing the window button.
As far as I understand the relays for the front windows are located in the FRM module. That leads me to the conclusion that the FRM unit is faulty. I doubt that it would be a faulty relay.

Could somebody with better knowledge of the FRM please advise if re-programming it could fix my issue?

[Johnes]

About two months ago I decided to pull the FRM module out and have a look at it. When I opened it, I found green corrosion on the PCB. So it was probably shortening somewhere when rolling the drivers window down.
I tried to clean the whole PCB with 99% isopropyl alcohol because I had success cleaning water damaged iphones with it. I cleaned it, dried it and put it back the next day. The window worked like a charm.
After doing some reading, I decided to put a conformal coating on the PCB to prevent it from corrosion. There was originally some conformal coating on the PCB, not sure if a silicone or an acrylic one.
I went with an acrylic coating. Unfortunately, after the spraying and drying the driver's window didn't work at all. It was quite disappointing.
So I gave up, went on eBay and ordered a used FRM module. Installed it and coded ti today and everything works.

I hope this will help if somebody is experiencing the same issues as I did.

[simster007]

Originally Posted by Johnes

About two months ago I decided to pull the FRM module out and have a look at it. When I opened it, I found green corrosion on the PCB. So it was probably shortening somewhere when rolling the drivers window down.
I tried to clean the whole PCB with 99% isopropyl alcohol because I had success cleaning water damaged iphones with it. I cleaned it, dried it and put it back the next day. The window worked like a charm.
After doing some reading, I decided to put a conformal coating on the PCB to prevent it from corrosion. There was originally some conformal coating on the PCB, not sure if a silicone or an acrylic one.
I went with an acrylic coating. Unfortunately, after the spraying and drying the driver's window didn't work at all. It was quite disappointing.
So I gave up, went on eBay and ordered a used FRM module. Installed it and coded ti today and everything works.

I hope this will help if somebody is experiencing the same issues as I did.

Was it difficult to code the new frm?

[e90yyc]

Originally Posted by simster007

Was it difficult to code the new frm?

No, it’s fairly straightforward. You’ll just need a K+DCAN cable and software like NCS Expert. Lots of tutorials online.

Only thing is make sure you get the correct FRM module. There are many versions, and the one you’ll need depends on your vehicle’s options, put simply.