TPMS Sensor Description and Operation

Description

1. 1
   General Description: The wheel unit (WU) is a sensor mounted inside the tire that reports pressure and temperature. The WU is mounted inside the wheel and fastened to the valve. The angle between the valve and the WU body is variable, which allows adaptation to different wheel types. The wheel unit consists of a printed circuit board supporting the electronic components, enclosed in a polyurethane-filled housing. It is powered by a battery and includes all systems for measuring parameters (pressure, temperature and centrifugal acceleration, and optionally rotation direction), radio frequency transmission and LF detection. To achieve the specified battery life, the WU supports different measurement and transmission timings depending on the WU operating mode. For RF transmission, the WU uses an internal antenna.
2. 2
   First Block Mode: When the vehicle starts moving, the sensor enters first block mode. The typical radio transmission period is 16 seconds, 40 times, for the auto-learn and auto-location function.
3. 3
   Driving Mode: After 19 minutes of parking, and after completing first block mode, the WU enters driving mode. The typical radio transmission period is 64 seconds when vehicle speed is above 4 g.
4. 4
   Parking Mode: When vehicle speed is below 3 g, the system enters parking mode. The typical radio transmission period is 13 hours.