Tire pressure sensor
WARNING: This page is about a different car, the 2009 Acura MDX, 2008 Acura MDX, and 2007 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.
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 internal tire information to the control unit once every 60 seconds. When the TPMS control unit receives tire pressure of less than 175 kPa (1.8 kgf/cm2 , 25 psi), the control unit then turns on the low tire pressure indicator and the appropriate tire{s) indicator. When that tire's pressure is increased to more than 200 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.