^^ This statement is correct.
If you want to trouble shoot the solenoid, remove the shift nob, remove the cover (the thing that has P,R,N,D etc) by pulling upwards. Towards the passenger side of the hole you've just exposed is a WHITE connector connecting the solenoid to the wiring harness of the tranny and ecu (make sure your keys are not in the ignition or in the on position) If you disconnect this white connector (two halves click into eachother) you should be able to put it in park. Now you won't be able to drive the car normally as disconnecting this plug places your car in LIMP-HOME mode. Now if by doing this you were able to engage the transmission into park your culprit would be the brake switch as you are required to press the brake to place the vehicle in park. The reason I ask you to disconnect the solenoid is tofigure whether it is actually working.
I had the same problem. It was my brake pedal switch.
"If everything seems under control, you're just not going fast enough."
- Mario Andretti
1979 320is RiP
1994 318is Sold
1995 325is Sold
1995 530i Sold