Perhaps you could upload (to Steve) a copy of your 2008 Patriot Thunder Owner's Manual for the "Coach Assist" section.
It sounds like your 2008 PT has a new style dash cluster.
The 2007 PT and 2008 Marquis' owners manuals show they still use a physical gauge for air pressure - so your '08 must be the first to get a digital air pressure display.
My 07 PT has a small digital screen in the middle of the upper dash which allows you to scroll through a number of different information items, eg. a trip screen, one with temp, fuel, boost, oil, V, and Others which I can’t recall. However one screen is air pressure. And, I also have the useless gauges
UPDATE:
Jeff .”Does anyone have information on how to get the dash digital section to show up when the engine is not running? I'm trying to do the Air System Test.”
Turn the ignition to on, but don’t start. It’ll come back with engine not running. Then maybe bay door open if that is the case.
Then press the “M” button below the screen and you can cycle through the different options. Obviously mine was not running and it’s been sitting for quite some time, so no air.
Should work for you.
Apologies for upside down pics. Not going to spend time correcting.
Jeff