BMW iX3 Electrical Gremlins: Multiple System Failures

I have some experience working on EVs. Had a similar issue with my 2021 BMW i4 last winter. Initially thought it was the main battery, but turns out the 12V auxiliary battery wasn't holding charge properly. Sounds very similar to what you're describing! Took it to my regular workshop. They ran diagnostics and confirmed the auxiliary battery was failing to maintain proper charge, which was affecting multiple systems. Had them replace it, cost me around 290 Euro, but it fixed all those error messages and starting issues. What's your mileage and have you noticed any other warning lights? Also, how old is the auxiliary battery in your iX3? These details would help better understand if you're facing the same issue I had. Honestly, with these newer EVs, when you get multiple electrical gremlins at once, it's often the 12V system acting up rather than the main battery. Worth having it checked out before it leaves you stranded.

Thanks for sharing your experience! My iX3 has 102442 KM on the clock, and I just had it serviced last month. The symptoms you described with your i4 sound exactly like what I'm experiencing. Really helpful to know it might be the auxiliary battery, that's way less scary than thinking something's wrong with the main system! Will definitely get the 12V battery checked out asap before it gets worse. Fingers crossed it's just that simple fix like in your case.

Hey again! Yeah, after seeing your mileage numbers, I'm even more convinced it's the same issue I had with my i4. You know what's funny? My problems started right after hitting 100K too, even though I had regular services. These auxiliary batteries can be sneaky, they often don't show any warning signs until they're really struggling. Since you mentioned you just had it serviced, did they check the auxiliary battery voltage? Sometimes it gets overlooked during routine maintenance because everyone's so focused on the main battery system. In my case, the battery was technically still "working" but wasn't holding charge properly anymore. Quick tip from my experience, if you're planning to get it checked, try to do it soon. When mine started showing these symptoms, it got worse pretty quickly. Within a couple of weeks, I was getting unusual system shutdowns while driving, which was pretty nerve-wracking. BTW, after I got mine replaced, the car's been running like new for the past year. No more error messages, start-stop works perfectly, and all those electrical gremlins disappeared. Just make sure they use the right battery spec, these EVs are pretty particular about their auxiliary batteries.

Thanks so much for the follow-up info! No, they didn't specifically check the auxiliary battery voltage during the service, guess I should have asked about that. Pretty concerning to hear about those unusual shutdowns you experienced... definitely not something I want to deal with! I've actually already called my workshop and booked it in for tomorrow morning. Better safe than sorry, especially after hearing about how quickly your issues escalated. Really appreciate all the detailed advice, particularly about making sure they use the correct battery spec. Makes total sense these modern EVs would be picky about their components. You've helped me feel much more confident about what's likely wrong and how to fix it. Will update you once I get it sorted, hopefully with the same positive outcome you had. Thanks again for taking the time to share your experience!