BMW X7 Transmission Warning Lights and Grinding Sounds

Hey! I had similar symptoms with my 2017 BMW X5 (40i). Let me share what happened at the garage. Initially thought it was the transmission too, but turned out the wiring harness connecting to the transmission control module was damaged, causing false signals. The grinding noise and rough shifting were from the transmission trying to protect itself by going into limp mode. The mechanic found corroded pins in the connector and some chewed up wiring (probably from rodents). They had to replace the entire wiring harness assembly and reprogram the transmission control module. It was a serious issue that could've led to complete transmission failure if left unchecked. Best to have a BMW specialist check it out properly. These symptoms can be misleading, what seems like a transmission problem could just be electrical. The radiator oil pressure theory doesn't quite add up with these specific warning lights and symptoms.

Hey, thanks for sharing your experience with the X5! That wiring harness issue sounds exactly like what I'm experiencing. Do you remember roughly how much the repair ended up costing you? Also, has everything been running smoothly since the fix or have you noticed any other issues pop up? Been kinda worried about potential long-term problems even after getting it fixed.

Hey again! Just wanted to update you, turns out in my case it wasn't actually the wiring harness like I initially thought. I took it back to the mechanic and they discovered it was just a faulty connection to the radiator oil pressure sensor. Much simpler fix than expected! Only cost me 95€ to repair the cable and plug connection. My X5 has been running like a dream since then, no warning lights, no weird transmission behavior, nothing. It's been shifting perfectly smooth and I haven't had a single issue pop up. I was also worried about long-term problems at first, but honestly, once they fixed that sensor connection, everything went back to normal. Sometimes these BMW electrical gremlins can make you think the worst, but it's not always as serious as it seems. Really hope you get yours sorted out soon! Let us know what your mechanic finds.

Thanks so much for the follow-up! I actually just got back from the mechanic today. You won't believe it, my issue turned out to be pretty minor too. The transmission fluid sensor was acting up because of some dirt buildup, causing all those scary warning lights. The mechanic cleaned it thoroughly and replaced a worn-out connector. Only spent about half of what I was expecting, and my car's running perfectly now. The grinding noise is gone, and the transmission's shifting smoothly again. Such a relief, I was seriously worried I'd need a complete transmission overhaul! Funny how these BMWs can throw such dramatic warning lights for relatively simple issues. Really glad I didn't panic and rush into any major repairs. Thanks again for sharing your experience, helped me stay calm through this whole thing.