Tire pressure sensors (TPS) communicate with your vehicle’s computer relaying the pressure inside the tire.  If your vehicle is equipped with TPS and the tire pressure falls below the recommended pressure, you should see a tire pressure error on your dash.

Keeping tires properly inflated ensures your tires do not wear out prematurely.

TPS sensors should be replaced if they stop relaying tire pressure to the computer
A faulty TPS could cause damage to the tire as the owner may not be aware they are driving on an improperly inflated tire.  Driving on improperly inflated tires increases tire wear and the possibility of a blowout while driving.