BMW Window Failure After Mechanic Visit Raises Red Flags

I had a very similar issue with my 2009 BMW 3 Series 320d. The power windows stopped working completely after a routine service. Turned out the main power window switch module in the driver's door was defective. The mechanic found that water had gotten into the switch assembly over time, causing corrosion on the circuit board. Had to replace the entire driver's door master switch panel. The repair wasn't particularly complicated, but finding the genuine part took a few days. Not a serious mechanical issue, but definitely annoying. The warning light was because the system detected a fault in the window control module. After replacement, everything worked perfectly again. Been working fine for the past 2 years now. My suggestion would be to first check the fuses, then have someone scan for electrical faults specifically in the window control module. Given your car's age, it's a common wear point.

Thanks for sharing your experience with the window issue. That's really helpful to know it was the master switch panel in your case. I had my switch replaced about 6 months ago, can't remember exactly how much I paid for it though. Have you had any other electrical issues pop up since getting it fixed? When mine was repaired, the mechanic mentioned something about the wiring harness looking a bit worn too, but we didn't replace it at the time. Just wondering if I should keep an eye on that. Would be great to hear what your total repair cost was, if you don't mind sharing. Trying to figure out if I got a fair deal on mine.

Hey there! Happy to give you an update about my BMW 3 Series window situation. After getting the power window switch fixed at the mechanic's, everything's been working like a charm, no more issues whatsoever! The total repair came to 200 € for the switch replacement. I think you made the right call getting yours fixed too. About other electrical problems, nope, haven't had a single one since the repair. That's been a relief! Though I get why you're asking about the wiring harness. My mechanic actually did a thorough check of all the wiring when fixing the switch and regulator, and everything looked good. But it's smart to keep an eye on it, especially in these older BMWs. Quick tip from my experience, if you do notice any slight hesitation in the windows going up or down, get it checked right away. Much cheaper to fix small issues before they become big ones. The 200 € I spent was totally worth it for the peace of mind. Hope this helps give you some context about repair costs and what to expect long-term!

Thanks for all that info! Actually, I ended up taking it to a different mechanic yesterday. Turns out my issue was a bit different, they found a blown fuse and some damaged wiring from my last repair job. The total fix was cheaper than expected, just 150 € for parts and labor. The new mechanic was really thorough and showed me exactly what was wrong. They even checked all the other electrical connections while they were at it. Pretty relieved it wasn't anything major like I first thought. Funny thing is, they noticed the previous repair work wasn't done properly, which probably caused this whole mess. But at least now everything's working perfectly, all windows go up and down smoothly, and that annoying warning light is finally gone. Thanks again for sharing your experience. It really helped me make the decision to get a second opinion, and I'm glad I did!