Tire pressure sensor
Each sensor is an integrated unit made up of the tire valve stem, a pressure sensor, and a transmitter. The unit is attached to the inside of the wheel, around the valve stem. The sensor transmits the tire pressure to the control unit when tire pressure is less than 168 kPa (1.7 kgf/cm2 , 24 psi). The control unit then turns on the low tire pressure indicator and the appropriate tire indicator(s). When that tire's pressure is increased to more than 198 kPa (2.0 kgf/cm2 , 29 psi), the transmitter sends tire pressure to the control unit, and then the control unit turns the indicators off.