Here is an interesting (meaning "how dumb can I be?) story that happened on the way back from Nashville last month.
We stopped for fuel just before getting into NC, While the truck was filling up, I grabbed the IT and started checking tires. All good until I got to the last one which was the left steer tire. It read 147 or something higher than all the others. Well Crap-now what. Looked at the tire, felt it with my hand, all good. Double checked the temp. Yup Still 147.
I thought well maybe the plies were starting to seperate. So I drove the next 50 miles or so at 55. Didnt want to change the tire if I didnt have to. Stopped again at the "coffee recycling center" and checked the tires. This time the left steer was back down to normal and the right steer was hot. It finally dawned on me that the IT was picking up engine heat coming out of the wheel well.
As simple as this sounds, I never had that problem with the GMC and it took awhile to figure what was going on.
Lesson learned. pay attention to where you hold the gun and where you shoot the tire.