Tire Pressure Sensor
The Tire Pressure Monitoring System (TPMS) uses 'active' tire pressure sensors mounted on each wheel rim, inside the tire cavity. The tire pressure sensors are retained in position by the valve attachment to the wheel structure and transmit their Radio Frequency (RF) signals at 433 MHz.
The tire pressure sensors periodically measure the pressure and temperature of the air inside the tire, plus the centripetal acceleration acting on the sensor. These measurements are transmitted periodically to the RF receiver integrated in the Tire Pressure Monitoring System Control Module (TPMSCM).
The tire pressure sensors are self-contained battery powered units which have no electrical connections into or out of the sensor.
When you replace the tire pressure sensor, also replace the nut and seal. Tighten to the required torque value.
The RF transmission from the tire pressure sensor contains a unique identification code in its transmission data. The TPMS can identify the tire pressure sensor through the unique code. When a tire pressure sensor has been replaced on a wheel, the identification for that sensor can be programed into the TPMSCM using Jaguar Land Rover (JLR) approved diagnostic equipment.
If the tire pressure sensor identification is not programed in, the TPMS can learn the new sensor identification and localize to the correct wheel position automatically.
To conserve the battery power of tire pressure sensor, the sensor uses different transmission rates when the wheel is stationary or moving. The wheel speed required to change between the stationary and moving transmission rates is very low to allow for slow driving.