My 2019 RAM 1500 Sport is doing something similar, although I get the "Parking Brake Unavailable" message usually while driving at a steady speed. The error will pop up on the dash and the screen goes blank but in most cases it will repeat two or three times, and then go away.
@jsnathan:
The shifter knob going into "P" at a slow speed makes me think the Park Assist braking scheme is taking over, as though something is sensed in front of your vehicle, so it brakes for you.
I've experienced the parking brake being applied AND the shifter going to "P" automatically when trying to back up slowly and opening my driver's door for a better look (old school style), in which case, I believe the vehicle is trying to prevent me from hopping out of the driver's seat while in gear - which cabe annoying but makes sense.
It seems like the "Parking Brake Unavailable" message issue could be related to parking assist being enabled or disabled (likely enabled), but also speed-related in that it would likely brake my vehicle if it occurred while I was driving slowly.
I'm wondering if a related parking sensor might be loose, or something more specifically related to the parking brake is loose or intermittent, so I'm going to wait for the next error to occur, and when it does I'll disable my park assist for a while and see if the message continues to be persistent, or if it goes away.
Either way, we might be on the right track with narrowing down the conditions for the "Parking Brake Unavailable" message, but finding the cause may still be a whole different challenge.
Appreciate your post, thanks.
