BMW iX3 Transfer Case Failure Causing AWD Malfunction

Hey there! I had very similar issues with my 2018 BMW i3s. Started with jerking movements and transmission problems, and those pesky warning lights in the cluster. Initially thought it was the transfer case too, but it turned out to be a faulty ABS sensor that was messing with the entire system. The bad sensor was feeding incorrect data to the car's computer, which made the traction control and stability systems go haywire. This triggered a chain reaction affecting the transmission control module. When I brought it to the garage, they found that moisture had corroded the sensor connections, which then caused issues with the wheel speed readings. It was quite serious because the faulty readings could've potentially affected the car's stability control in emergency situations. The fix involved replacing the ABS sensor, cleaning up the corroded connections, and recalibrating the entire system. The mechanic also had to clear all the error codes and run a full diagnostic to ensure no other systems were affected. My advice? Get it checked ASAP. These symptoms might seem like a transfer case issue, but it could be something else entirely affecting multiple systems.

Thanks for sharing your experience! Yeah, that's exactly what happened to me. Going through the sensor replacement really sorted things out for me too. Out of curiosity, do you remember roughly how much you ended up paying for the whole repair? And has everything been running smoothly since, or have you noticed any other quirks popping up? Just trying to figure out if I should expect any follow-up issues. Would love to hear how it's been holding up for you.

Hey again! Great to hear back from you! Since you asked, after I got it fixed at the dealer, I literally haven't had a single issue with the transfer case or those annoying warning lights. The best part? It didn't cost me anything because it was covered under warranty since it was a consequential fault from the ABS system problems. My i3s has been running like a dream since then, no jerking, no transmission problems, nothing. It's been about 8 months now and the car feels as smooth as it did when it was new. The mechanic really knew their stuff and properly diagnosed the root cause instead of just treating the symptoms. Just keep an eye on those sensors, sometimes they can get dirty or corroded again, but it's pretty rare. I've been taking mine through automated car washes without any problems. Honestly, once they fix it properly, you shouldn't have any follow-up issues. These BMWs are pretty solid once you sort out any electrical gremlins! Let me know if anything else comes up, always happy to share what I've learned from my experience!

Thanks for the detailed update! Just got back from the mechanic today and wanted to share what happened. They found it wasn't just the ABS sensor, turns out there was a wiring harness issue too. The mechanic showed me where some wires had gotten worn down, causing those crazy warning lights and jerking problems. Cost me a bit more than I expected, around 800 bucks for parts and labor, but at least it's fixed now. Took her for a test drive and she's running smooth as butter. No more warning lights, and the transmission's shifting perfectly again. Funny thing is, the mechanic actually remembered working on another iX3 with the same problem last month. Makes me wonder if it's a common issue with these models. Anyway, really appreciate your help earlier, it gave me a good starting point when talking to the mechanic. Think I'll keep a closer eye on these electrical issues from now on!