ACDelco GM Original Equipment Tire Pressure Monitoring Sensors (TPMS) are battery powered sensors located in the tire that monitor the vehicleÆs tire pressure and warn the driver when pressure falls more than 25% below the manufacturerÆs recommendations (normally through a slow pressure loss), and are GM-recommended replacements for your vehicleÆs original components. The sensor is connected with the valve stem and, by way of Radio Frequency (RF) technology, sends pressure updates to the vehicleÆs on-board computer. Tire pressure is displayed on the vehicleÆs Driver Information Center (DIC) or, when low, a warning light may be illuminated to warn the driver. U.S. Federal Regulations require that new cars and light trucks be equipped with TPMS starting in 2008. These original equipment tire pressure monitoring sensors have bn manufactured to fit your GM vehicle, providing the same performance, durability, and service life you expect from General Motors.