Problems getting key out of ignition

I have the same problem with my 2001 Pontiac Grand Prix. I have checked the console for any type of beverage and found none. I checked the fuses and they were a little low. Which ones had to be at twelve volts? When removing the key, I repeatedly push the button on the shifter, leaving a few seconds in between each time, to engage the twelve volt pulse to the ignition solenoid until I hear the click. Sometimes it has a delay when it sends the pulse, but most of the time it is instant. Is there any way to tell if it is the solenoid from the shifter or the ignition? Could it be something else?

Welcome to AF.

I have moved your post from the Buick Regal forum to Pontiac Grand Prix forum. There are differences in the shift interlock and key release system although they are similar platform GM "W" body cars.

The BTSI fuse was measured at 11.77V, and the battery was measured at 12.65V.

That is too much of a voltage drop for the shift interlock solenoid. I would systematically check the BTSI circuits and try to illiminate components like the shift solenoid, brake switch, BTSI fuse socket, wiring, etc. It would help to have the GM wiring diagrams. I'd have to double check the wiring diagrams but even a bad contact in the ignition switch could be the cause. Some Grand Prixs, can't remember which specific years, had flaky BTSI fuse sockets.

And are you sure nothing like coffee or soda was spilled on the console?