BMW i3 Hybrid Problems: Stalling and Rough Running Issues

Hey there! Got some experience with hybrids (moderate level). Had a similar issue with my 2019 BMW i8 (also test drove the iX3 before getting it). My symptoms matched yours exactly, check engine light, rough idle, the whole deal. Turned out it was just a loose connection in one of the main sensor cables. My trusted mechanic found it pretty quick, basically a cable connecting to the powertrain control module wasn't properly seated. Cost me 95 Euro for the diagnostic and fix. Such a relief it wasn't anything major! Before I can give you more specific advice though, could you share: How many miles/kilometers on your i3? When did these symptoms first start? Any recent maintenance or work done? Might help pinpoint if we're dealing with the same gremlin.

Thanks for your detailed response! My i3 has 141723 KM on the clock, and these issues started right after my latest service about 2 weeks ago. No other work was done besides the routine maintenance. Your experience with the loose connection sounds promising, definitely less scary than what I was imagining! Were you also getting jerky acceleration when your sensor cable was loose? The stalling at idle is what's really worrying me, especially since it's been happening more frequently lately. I'll have my mechanic check the connections first before diving into replacing parts. Fingers crossed it's something similarly straightforward!

Hey again! Yeah, I totally get your concern about the stalling, had the exact same worry with my i8. And yes! The jerky acceleration was actually the first symptom I noticed before everything else started acting up. It's funny you mention it happening after a service, that's exactly when my issues started too. Pretty sure someone didn't properly reconnect something during the routine maintenance. Since you're at 141k km, you're pretty close to where I was when this happened to mine (around 138k). The stalling got worse for me too before I got it fixed. Just make sure your mechanic thoroughly checks all the connections around the powertrain control module, these hybrids are super sensitive to even slightly loose connections. Quick tip: when my mechanic was diagnosing it, he also checked the hybrid system voltage sensor connections since they can cause similar symptoms. Might be worth having them look at that too while they're at it. Let me know how it goes, really hoping it's just a loose connection like mine was. These cars are amazing when everything's properly connected!

Thanks so much for all this info, it's super helpful! Really relieved to hear that your similar issues were just down to loose connections. I've just booked my i3 in with my mechanic for tomorrow morning and mentioned everything you've said about the connections and the hybrid system voltage sensors. You're probably right about something getting knocked loose during the service. Makes total sense since the timing matches up perfectly. I'll definitely have them pay special attention to all those connections around the powertrain control module. I'm feeling much more optimistic now, was honestly dreading some massive repair bill! Will definitely double-check everything's properly connected after future services too. Thanks again for sharing your experience, it's been incredibly helpful. I'll update you once I get it sorted!