What is the button on the dash (below the ac) that has a P ^ (triangle)

It's your rear parking sensor "off" switch. If you have a trailer connected, you can turn off the back-up beepers which will go nuts if you're trying to back up a trailer. If you have the lights plugged in, it usually turns the back-up sensors off automatically. Hope that helps!

That was it thanks

I have found that when sitting in the passenger side of my 2008 f150 the big "P^" button will turn on when pressed. I think it is to turn on the passenger side airbag. The truck must be running. That button has a light in it that said off. There is a light above the radio that indicated that the passenger side airbag was off when there was a child or a box of something in the seat. This may automatically turn off if children are in that seat. Or it is for something else.

What causes the P button to be stuck on off? In a 2006 Ford f-150 lariat

What causes the P button be stuck off? On my Dodge Ram 2018 when hauling