BMW 2 Series Auto Transmission Issues, Grinding & Faults

Hey there! Had something very similar with my 2019 BMW 3 Series diesel. Being somewhat experienced with cars (I do basic maintenance myself), I was quite worried when my X4 started showing those exact symptoms. The grinding and rough shifts were super annoying, and I got similar error codes. Took it to my trusted workshop, and they diagnosed a faulty transmission control unit. The repair set me back about 1000 Euro, but it fixed the issue completely. The shifts are smooth again, and all warning lights are gone. Could you share more details about when these symptoms started and if you notice any pattern (like when the engine is cold/hot)? Also, what specific error codes are you getting? This would help confirm if we're dealing with the same problem.

Thanks for sharing your experience! I've got 143097 KM on mine and just had the service last month. The symptoms started appearing more frequently when the engine's warm, especially during highway driving. Getting P0730 and P0733 error codes. Did your mechanic mention anything about the transmission fluid? Just trying to get a rough idea of repair costs before taking it in.

Oh yes, I remember dealing with this! When my mechanic worked on my BMW 3, they actually checked the transmission fluid first, it's always good to start with the basics. In my case, while the fluid level was fine, they found it was quite degraded and had metal particles in it. Actually, those are the same error codes I got (P0730 and P0733). Looking back, I probably should've mentioned the transmission fluid in my first response. The mechanics did a complete fluid flush and filter change before diagnosing the faulty transmission control unit. The fluid change alone was around 300 Euro, but they said it was necessary to rule out simpler issues before jumping to the control unit replacement. With your mileage being similar to what mine was when the problem occurred (I was at about 138000 KM), it really sounds like you're dealing with the same issue. The warm engine symptoms are identical too, my problems were always worse after about 15-20 minutes of driving. One thing I learned: don't wait too long to get it fixed. I drove it for about two weeks with these symptoms, and my mechanic said I was lucky not to cause more damage to the transmission. Better to get it sorted sooner rather than later.

Thanks so much for all this detailed info! Really appreciate you taking the time to share your experience. It's actually quite reassuring to hear someone had the exact same problem and got it fixed. The similarities in symptoms, mileage, and error codes are pretty striking. I'll definitely take your advice about not waiting too long, planning to book it in tomorrow morning. The total cost you mentioned (around 1300 Euro including fluid change and control unit) gives me a good baseline for what to expect. At least now I won't be completely in the dark when talking to the mechanic. Think I'll ask them to check the transmission fluid first, as you suggested. Makes sense to start with the basics before replacing more expensive parts. Really glad I asked here, feels much better going to the workshop with some knowledge about what might be wrong. Thanks again for your help! I'll probably update once it's fixed in case anyone else runs into the same issue.