BMW i3 Electrical Nightmare: FlexRay Bus System Failure

Hi there! I have some experience working on hybrid vehicles and went through something very similar with my 2012 BMW i8. Also owned an ActiveHybrid 5 before. The symptoms you're describing sound exactly like what I dealt with, total electrical chaos! Turned out the issue was a faulty connection in the main wiring harness. My trusted mechanic found that one of the connector plugs had corroded, causing all those system failures. The fix wasn't too complex once they identified the problem. They replaced the damaged connector and cleaned all the connection points. Cost me around 95 Euro and it's been running perfectly since then. Could you share which error codes you're getting? That would help pinpoint if it's the same issue I had. Also, did you notice any warning lights before the systems started failing?

Thanks for sharing your experience! My i3 just hit 69775 KM and had its latest service two weeks ago. The error codes I'm getting are similar, B7B241 and U112F. Before the complete system failure, I noticed the battery warning light flickering for about a day or two. It's interesting you mention the wiring harness because I've been suspecting something similar, though my mechanic initially thought it might be the voltage converter. Did your car also have issues starting up, or was it just the electrical systems acting up? Mine occasionally takes multiple attempts to start, which seems related to this whole mess.

Hey again! Thanks for sharing those details about your i3. Yeah, those error codes definitely ring a bell, had almost the same ones in my i8 before everything went haywire. And funny you mention the starting issues, because that's exactly how mine started acting up too! Had to cross my fingers every time I tried starting it. Looking at your mileage and those symptoms, I'm even more convinced it's similar to what I experienced. The flickering battery warning light is particularly familiar, mine did that for about three days before things got really bad. My voltage converter was actually fine when they checked it, just like yours might be. What really sealed the deal for me that it was the wiring harness was when the audio would out of nowhere cut out while driving, especially when going over bumps. Did you notice anything like that? The corrosion in my case was actually worse than initially thought, they found it had spread to several connecting points. Quick tip from my experience, might be worth asking your mechanic to specifically check the ground connections near the battery management system. That's where they found the worst corrosion in my case. The whole repair ended up taking about 4 hours, but at least it sorted everything out in one go. Have you had any other weird electrical glitches? Like unusual warning messages on the display or the climate control acting up? These were some other symptoms I noticed before getting it fixed.

Thanks everyone for the helpful responses! After reading about your experiences, especially with the i8, I'm definitely going to have my mechanic take a closer look at the wiring harness. And yes, now that you mention it, my audio does cut out over bumps! It's super annoying and happens pretty much every time I hit a rough patch of road. I've actually noticed those other electrical glitches you mentioned too. The climate control has been going crazy, sometimes blasting hot air when it's set to cool, and I'm getting unusual warning messages popping up on the display. It's really reassuring to hear that fixing the wiring harness sorted out all these issues for you. I'm going to take it back to my mechanic tomorrow and specifically ask them to check those ground connections near the battery management system. Really hoping it's the same issue you had and can be fixed for a reasonable price. You've been super helpful, I'll update once I get it sorted!