Hello! First Time visiting this forum

I have a 2006 3.2 VR6 Cayenne, which came with a CDR-23 Radio (the stock single din). I was given a PCM (the double din which came stock in a Turbo) and tried to install it. The two black plugs, the brown one, and the antenna plugged in perfectly, and the radio turned on perfectly and it started playing FM radio, but the buttons in the PCM don't respond. However the steering wheel controls work. The radio displays an error message for not having an amplifier nor navigation. The radio was taken out of an 04 S, and was working like it was supposed to. What can be the problem? The radio physically is in great condition, and sounds great. Thanks!

Shortlist
-PCM retrofit into an 06 3.2
-Sounds and looks great
-Not one button works