BMW iX Electric Motor Issues: Jerking & Power Loss

Hey there! I have some experience working on EVs and went through something very similar with my 2021 BMW i4. Sounds a lot like what happened after I got a third-party chip tuning done to boost performance. The symptoms were exactly what you're describing, jerky acceleration and reduced power. After a nerve-wracking week, I took it to a certified workshop. Turned out the aftermarket tuning messed with the motor control unit. Cost me about 180 Euro to get it reset to factory settings and properly recalibrated. Before I can help more specifically, could you tell me if you've had any recent modifications or tuning done to your iX? Also, what's the exact fault code you're getting? That would help narrow down if we're dealing with the same issue. Hope this helps! Just keep in mind that aftermarket mods can be tricky with EVs.

Thanks for sharing your experience with the i4! To clarify, my iX is completely stock with no modifications. Just had the latest service done at 184273 KM. I probably should've mentioned that in my initial post. The fault code is showing E-1246, which seems related to the motor control unit but I'm not entirely sure. Pretty worried since this is my daily driver and these symptoms just started appearing out of nowhere this week. Really appreciate the help in figuring this out. Was hoping to avoid an expensive workshop visit if it's something simple.

Ah, thanks for clarifying about your stock iX! Yeah, that definitely changes things from my initial thoughts about tuning being the culprit. You know what's interesting, I had a similar fault code (E-1246) pop up in my i4 about 6 months after my tuning saga, but this time it was totally unrelated to any mods. Turned out the motor control sensor was acting up due to some electromagnetic interference. In my case, it was actually a pretty quick fix, they updated the control unit software and replaced a faulty sensor. Cost way less than I expected, around 250 Euro total. Since you mentioned you've just had your service done, I'd actually suggest checking if there might be a connection there. Sometimes these issues can pop up right after routine maintenance if something wasn't properly reset or if there was a small oversight during the service. I know you wanted to avoid a workshop visit, but with that specific fault code and the symptoms you're describing, I'd really recommend getting it checked out soon. These motor control issues can sometimes get worse if left unchecked. The good news is, if it's similar to what I experienced, it shouldn't be too complicated or expensive to fix. Have you noticed if the jerking gets worse during specific conditions, like when the battery is at a certain level or during rapid acceleration?

Thanks for that detailed response! You've got me feeling a bit more optimistic about the situation. The jerking definitely gets worse when I'm trying to accelerate quickly, especially when merging onto highways. Haven't noticed any correlation with battery levels though. I just called the workshop where I had my recent service done, and they mentioned they did update some control modules during the service. Your comment about issues popping up after maintenance makes a lot of sense now. They've agreed to take a look at it tomorrow without charging a diagnostic fee since it might be related to the recent service. Really appreciate you sharing your experience with that fault code. Definitely gives me some peace of mind knowing it might just be a sensor or software issue rather than something major with the motor itself. I'll update the thread once I get it checked out, might help others who run into similar issues with their iX. Thanks again for taking the time to help troubleshoot this! Always great to learn from others' experiences with these high-tech EVs.