One of your TPS sensors has probably met it's 10 year lithium battery life and died, they can install a new one at the tire shop. Be forewarned, those TPS valve stems can be pricey at the tire outlet stores, you are far better off to order them online via the mail and then have the new TPS valve stem(s) installed at the tire shop. If one is bad and over 10 years old, they are all about to fail soon if they are all the original TPS valve stem sensors. The TPS 10 year lithium battery is a permanent internal part of the TPS valve stem, the battery can't be replaced, a new TPS must be installed and learned into to the BCM (cars body control module) via the cars owners manual instructions. Some cars have a TPS on the spare tire too, if your car doesn't display the location information. Some early Toyota PU's and 4runners had just the TPS idiot dash light which gave no vehicle location info and a TPS sensor on the full sized spare tire under the cargo bed. Many Toyota truck owners were astonished when I told them that they had to put the spare tire back on the truck after they abandoned the stock full size spare due to lifting / installing oversized custom wheels and tires.
I see a bunch of people comment here that don't know how to use a tire whacker properly, most truck drivers of low IQ can learn to do it (18 tires on your knees in the snow). I can tell with one tap of a led shot plastic hammer, granted most big truck tires are 75-80 psi. I can easily punch a car tire with my fist and tell the difference between 32 and under 20 psi without using or the need for a gauge. The TPS's on my cars don't flag until the tires drop below 22 psi.