How to troubleshoot a transmission that won't shift into gear?

I've been experiencing problems with my transmission not shifting into gear. It's a BMW 3 Series with automatic transmission. I've had it looked at by a mechanic but they couldn't find anything wrong. What could be causing this issue?

Hi Maggie, it's possible that the issue could be with the transmission fluid. Have you checked if it's at the correct level and if it needs to be replaced? Another possibility could be a faulty shifter cable, have you had that checked?

Hey Maggie, have you noticed any strange noises or vibrations when trying to shift gears? This could indicate a problem with the transmission's solenoid. It's best to get this checked by a professional mechanic.

Hi Maggie, have you tried resetting the transmission control module? This could potentially resolve the issue. If not, it could be a mechanical problem with the linkage or clutch system. It's best to have a specialist take a look.