BMW i8 Window Regulator Failure: Fixes & Expert Tips

Hey there! I had a similar issue with my 2017 BMW i3. Initially thought it was just the window regulator, but it turned out my battery was on its last legs. The low voltage was causing electrical system issues, including the windows not functioning and unusual error codes popping up. Got it checked at the garage last month. They ran a full diagnostic and found the original battery had degraded significantly. They had to replace the battery and then reinitialize all the electrical systems. The whole process took about half a day, including programming and testing all power windows. It wasn't a super serious issue, but definitely something that needed immediate attention to prevent other electrical problems from developing. After the fix, all the error codes cleared up and everything's been working perfectly. If your symptoms are similar, I'd recommend getting the battery tested first before diving into window regulator repairs. These hybrid systems can be sensitive to battery performance. Take care

Thanks for sharing your experience! That's really helpful since it sounds exactly like what I'm dealing with. I'm starting to think it might be battery-related in my case too. Would you mind telling me roughly how much you ended up paying for the whole repair? Also, curious to know if you've had any other electrical problems since getting it fixed?

Hey again! Happy to report back! Since you asked, the total bill came to 290 € for the battery replacement, and honestly, it was worth every penny. The mechanic sorted out the window regulator initialization problem right away, and everything's been running like clockwork since then. You know what's interesting? Haven't had a single electrical issue pop up after getting the battery replaced. It's like getting a fresh start, all those annoying error messages disappeared, and the windows work perfectly now. I was actually surprised at how many little quirks were connected to the aging battery. The whole repair was much more straightforward than I initially feared. The shop had it done in just a few hours, and they even did a full system check to make sure everything was working properly. If your symptoms are matching what I had, you're probably looking at a similar fix. Just a heads up though, make sure they use the right battery spec for your i8. Being a hybrid, it's a bit pickier about these things than regular cars. Best of luck with getting it sorted!

Thanks for all the details! I went ahead and took your advice today. Turns out you were spot on about the battery issue. The mechanic I found was really thorough, ran all the diagnostics, and confirmed it was the same problem you had. The repair was actually cheaper than I expected, came in at 265 €. Got to say, the car feels completely different now. Not just the windows, but everything's running smoother. The error codes are gone, and all the electronic systems are working perfectly. The mechanic mentioned that hybrid batteries can affect multiple systems when they start failing. Really glad I asked here first instead of jumping straight into replacing the window regulators. Saved me both time and money! Thanks again for pointing me in the right direction. I'll definitely keep an eye on the battery performance going forward. Also, the mechanic I found was great, super knowledgeable about BMWs and hybrids. What a relief after my previous bad experiences with repairs!