BMW X7 Transmission Issues: Warning Lights & Rough Shifts

Hi there! I have some experience working on cars and faced something very similar with my 2021 BMW X5 last year. When I got those exact same symptoms, transmission warning, check engine light, and rough shifting, it turned out to be low transmission fluid level. My local workshop discovered it during diagnosis. They did a complete gearbox oil level check and refill, which cost me 365 Euro. Since then, it's been shifting smoothly with no warning lights. Before you head to the shop, could you share: How many miles/kilometers on your X7? Have you noticed any fluid leaks under the car? Did this start suddenly or gradually? I know the X3 and X7 share similar transmission systems, so this might help pinpoint the issue. Let me know these details and I can share more from my experience.

Thanks for your response! I've got 50204 KM on my X7, and just had my service done last month. No fluid leaks that I can see underneath. The issue actually started quite suddenly, was driving normally yesterday when the warnings popped up and the transmission began acting weird. I'm crossing my fingers it's just a sensor issue like yours and not something more serious! Would make sense since everything was fine during my recent service. Did your car also go into limp mode when you had the low fluid problem?

Hey again! Thanks for those details. You know what, when I had my X5's issues, it did go into limp mode, but my situation was a bit different from yours. Since you've just had a service and there's no visible leaks, I'm starting to think it might not be the fluid level like in my case. In my experience, sudden issues like this, especially right after a service, often point to electrical problems. When my transmission started acting up again a few months after the fluid fix (yeah, I had multiple issues, lucky me), it turned out to be a faulty wiring harness connecting to that pressure sensor we talked about. The symptoms were identical, warning lights, limp mode, the whole nine yards. Cost me around 600 Euro for the repair, but it was worth it because it solved the problem completely. The mechanic showed me how the wires had gotten corroded and were sending wrong signals to the transmission control unit. Since your X7 is still pretty new, you might want to check if it's covered under warranty. Mine wasn't, being a 2021 model with higher mileage when it happened. If you're heading to the dealer, ask them specifically to check the wiring harness and connections to the pressure sensor, it might save some diagnostic time. Have you noticed any other electrical glitches lately? Like flickering lights or weird behavior from other systems?

Thanks for all that detailed info, really helpful! No, I haven't noticed any other electrical issues, which makes the wiring harness theory interesting. You've actually made me feel a bit better about the whole situation. I was worried it might be a complete transmission failure, but what you're describing sounds more likely, especially since it came on so suddenly. I just checked, and my X7 is still under warranty, thank goodness! I've booked it in for tomorrow morning and will definitely mention the wiring harness and pressure sensor connection issues you experienced. Hopefully, it'll be a similar quick fix like yours. Really appreciate you taking the time to share your experience, it's given me a much better idea of what to expect and what to ask about at the workshop. I'll make sure to post an update once I find out what's actually causing the problem. Thanks again!