BMW M2 Start-Stop Failure Causing Engine Shutdowns

Hey there! I had a similar situation with my 2018 BMW M4 last year. The symptoms match what I experienced, start-stop failure, unusual engine cuts, and warning lights. Took it to the garage and after diagnostics, turns out the battery was severely discharged and couldn't hold proper voltage anymore. This was causing the electrical systems to malfunction, including the start-stop feature. The battery being weak also triggered various error codes. It was actually quite serious because a failing battery can damage other electrical components and leave you stranded. In my case, they had to replace the battery and recalibrate the battery management system. Definitely not something you want to postpone. I'd strongly recommend getting it checked soon, as driving with these symptoms could lead to bigger problems. Make sure whoever works on it knows BMWs well, these cars need specific coding when replacing batteries. Hope this helps!

Thanks for sharing your experience! It definitely sounds like what I'm dealing with. Would you mind telling me roughly how much you ended up paying for the whole fix? Also curious if you've had any other electrical gremlins pop up since getting the battery replaced? Just want to make sure I budget properly and know what to look out for.

Hey again! Just wanted to follow up and let you know that getting my battery issue sorted out was totally worth it. The repair cost me 290 € and since then, my start-stop system has been working perfectly, no more unusual engine cuts or warning lights! I know you asked about other electrical issues, honestly, everything's been running smoothly since the fix. The battery was definitely the culprit of all those problems. Once they put in the new one and did all the proper coding, my M4 has been running like a dream. Got to say, I was pretty relieved it wasn't anything more serious. The symptoms can seem really scary when you're experiencing them, but a failing battery can cause all sorts of weird electrical behavior in these cars. If you're dealing with similar symptoms, I'd say go for it, the peace of mind is totally worth the cost. Just make sure you get someone who knows what they're doing with BMW electrical systems. The coding part is super important to get right. Let me know if you need any other info!

Thanks everyone for the advice! Just wanted to update you on what happened. After getting all your helpful feedback, I bit the bullet and took my M2 to a different mechanic who specializes in BMWs. Turns out you were spot on, it was indeed the battery causing all the trouble! Got it replaced and properly coded, cost me about 350 bucks total. The mechanic was super professional and explained everything clearly. Even showed me how the old battery was struggling to maintain proper voltage. Been driving for a couple weeks now and everything's working perfectly. No more unusual shutdowns, warning lights are gone, and the start-stop system is back to normal. Such a relief it wasn't something more serious! Actually really glad I asked here first, saved me from stressing too much about it. And found a great mechanic in the process too. Definitely keeping this place for future maintenance. Thanks again for all your help!