the wife an i just got an 06 armada se 4x4 an it has 20's on it. it has 37 thousand miles on it. but anyway on the way home the low tire pressure light come on an i checked the tire pressure an they all have 40psi in them. they have more than the truck requires. so why is the light coming on?

They probably didn't put the sensors in the 20's or one of them is bad. Are they rubber valve stems or metal ones?

they are metal valae stems

hmm... then one is more than likely bad.

Pull up the tire pressures on your display an see which one isn't reading. You might have to play with it by letting one tire down a few pounds at a time to se which sensor goes to what position on the display.

i dont have an display. that is the thing that is above the radio right?

yup the navigation screen. But don't have that. So I don't know how to check that.

Sorry, I didn't look at your post close enough. I was thinking it was newer. You may have to do o a dealer and let them initialize them to see.