The Tire Pressure Monitoring System (TPMS) is to monitor the tire inflation pressure and gives the information of tire inflation pressure to the driver by showing the warning light on the instrument panel. The Tire Pressure Monitoring System (TPMS) consists of four wheel-mounted tire pressure sensor unit (TPMS transmitter), a receiver and a warning light. The wheel-mounted sensor unit is an assembly consisting of the pressure sensor, related electronics, and power source. The tire valve stem is integrated into the assembly. Refer to Wheels/Vehicle Underbody Component Views .