TPMS Sensor
Tire Pressure Monitoring System sensor—a battery-powered electronic device mounted inside each wheel that measures tire pressure and temperature, alerting the driver to low inflation.
The TPMS sensor is a small electronic transmitter mounted to the inner end of the tire valve stem inside the wheel. It continuously measures the air pressure and internal temperature of the tire and broadcasts this data wirelessly to the vehicle's computer.
If tire pressure drops 25% or more below the manufacturer's recommended level, a warning light shaped like a horseshoe with an exclamation point illuminates on the dashboard. TPMS sensors are powered by non-replaceable lithium batteries designed to last 5 to 10 years; once the battery dies, the entire sensor must be replaced.
Common failure points include physical damage during tire mounting, corrosion of the aluminum valve stem, and dead batteries. Driving with properly inflated tires is essential for safety, fuel economy, and tire longevity.