Transmission issue

[Luiariy34]

Hi everyone this is my first post to the community as I haven’t seen this asked in any previous posts. A few days ago I took my 2003 M45 for a drive and on the way back noticed the car was acting as if it was in neutral while in drive. I could see the rpm’s go up on the gauge cluster but no acceleration. I pulled over and turned the vehicle off. After restarting it went into reverse and drive fine again for about 30seconds before again acting as if it was in neutral. It also threw on a service engine soon light. Since then I’ve checked ATF fluid and it has transmission fluid. I’m really hoping this doesn’t mean my transmission is out since it was working fine beforehand, (maybe a slightly harsh shift from 1st-2nd) although it seems to me it wouldn’t shift into gear at all if the transmission was blown?? Anyone have the same issue or might know a resolution before taking it to the shop since I’m not that mechanically savvy I don’t want to overpay for what could be something sensor related?

[Ilya]

Welcome!

What did the check engine light code read as? That's the first order of business.