Transmitter (Tire Inflation Pressure Sensor)

Remove the wheels from the vehicle. < Refer to REMOVAL , Tire and Wheel. >
Remove the tires from wheels.
CAUTION: Use a tire changer when removing the tire from the wheel.
Loosen the screw to remove the transmitter from the valve stem.
CAUTION: Do not reuse the valve and screw.
Replace the valve and screw with a new part even when reusing transmitter.

Fig 1: Identifying Wheel, Screw, Transmitter And Valve
Courtesy of SUBARU OF AMERICA, INC.
Remove the valve from the wheel.