Is this the test you are referring to?
Are the actuator motors stuck in one position? On my 2015 Caravan it does that when you want to start using the AC (after winter is done and it gets hot out).
The one giving me problems is the passenger side which is to the left of the glove box underneath the left part of the foot well carpeting.
What I found besides the obvious solution of new Actuator motors, was to find where the actuators are and if they are accessible, give them a few firm taps (don't go gorilla) with the side of a hammer. Then turn on the AC unit and cycle it between hot and cold and that seems to loosen up a stuck motor. At least on a Dodge Caravan.
Found online that folks say you can hold down buttons on AC module for it to go into diagnostic mode. Anybody out there know if this is true?
AS shown by others; yes - it's true, there is a self diagnostic test.
If you're only getting hot air, regardless of desired setting, then the BDA (blend door actuator) is bad. Not uncommon on the Panther cars. Not really "hard" to fix, but a long, tedious task. Have to pull the entire dash panel (the whole thing, not just the facia bits on the front) away from the chassis a bit to reach it. I did mine and successfully was able to do it in a few hours with help of a friend. There are many vids on this; watch several and you'll get the idea.