Where is the tire pressure sensor located?
2 Answers
Tire pressure monitoring sensors can be divided into internal and external types based on their installation location. Internal sensors are installed inside the tire, which is relatively more stable and provides more accurate temperature monitoring data. External tire pressure monitoring sensors are installed on the tire, usually at the valve stem position. There are three common methods of tire pressure monitoring: Direct tire pressure monitoring: Direct tire pressure monitoring devices use pressure sensors installed in each tire to directly measure the tire pressure. The pressure information is transmitted from inside the tire to a central receiver module via a wireless transmitter, and then the tire pressure data is displayed. The system automatically alerts when the tire pressure is too low or there is a leak. Indirect tire pressure monitoring: When the pressure of a tire decreases, the vehicle's weight causes the rolling radius of that wheel to become smaller, resulting in a faster rotation speed compared to other wheels. By comparing the differences in rotation speeds between tires, the system monitors tire pressure. Indirect tire pressure alert systems essentially rely on calculating the rolling radius of the tires to monitor pressure. Introduction to Tire Pressure Monitoring System (TPMS): It combines the advantages of both systems mentioned above. Direct sensors are installed in two diagonally opposite tires, and a 4-wheel indirect system is also equipped. Compared to using only a direct system, this hybrid system can reduce costs and overcome the limitation of indirect systems, which cannot detect simultaneous low pressure in multiple tires. However, it still cannot provide real-time data on the actual pressure in all four tires as a direct system does.
With years of experience in auto repair, I can confirm that tire pressure sensors are typically mounted on the inner side of the wheel hub, precisely positioned in the valve stem area—a common design feature of direct TPMS systems. The sensor's placement must be exact to ensure accurate wireless transmission of tire pressure data; even minor misalignment can trigger false alarms or system malfunctions. Indirect TPMS systems, however, don't involve physical sensor placement. During tire replacement, positioning is critical: handle sensors gently to avoid impact damage, and since their batteries have limited lifespan, always check mounting stability beforehand. Regular maintenance of sensor positioning prevents excessive battery drain—I recommend having technicians verify placement during routine servicing to proactively address safety risks that could compromise driving stability.
