OK. This code indicates that there is an issue with what's called the internal mode switch, or IMS. It is what we used to call the park/neutral switch, it tells the computer what gear the transmission is shifted into. If this switch doesn't work, the computer may not know it's in park, and therefore won't release the key.
Work the shifter through the ranges several times, all the way back as far as it will go, then all the way back to park, and see if the key releases. It may or may not, but this is worth a try.
This IMS is inside the transmission, not a very DIY friendly repair unless you're comfortable taking the pan off the transmission and poking around in there. There is also a calibration update for this, which I would perform first, but your dealer needs to do this for you. It may be fixed with some software, so always try that first, but it seems that worst case scenario here is that you need a new IMS.
My recommendation is to take it to the dealer for this programming, and perhaps further diagnosis if that doesn't fix it.