A TPMS relearn procedure is required any time a new sensor ID is introduced to the vehicle or when the tires are rotated. The vehicle's ECU records the four sensor IDs (or five when the spare tire is included) so that the unique IDs installed on the vehicle are correctly recognized by the vehicle's ECU.

TPMS or Tire Pressure Monitoring Systems are now standard equipment on today's passenger vehicles. TPMS sensors gather data in real time and often are attached to the back of the valve stem or banded to the wheel.

In the U.S. each year, hundreds of deaths in road accidents are attributed to tire defects, according to National Highway Traffic Safety Administration data. Adding TPMS to all vehicles is estimated to save 660 lives per year, as well as preventing 33,000 injuries annually.

TPMS sensors transmit all kinds of data in real time, such as unique sensor ID, tire pressure, tire temperature, sensor battery status and other details. The data are sent to the engine control unit (ECU) or a specific receiver on the vehicle at ultra high frequency (UHF).