Audi A4L checks tire pressure by selecting the tire pressure monitoring option through the system menu. There are three commonly used tire pressure monitoring methods: Direct Tire Pressure Monitoring: The direct tire pressure monitoring device uses pressure sensors installed in each tire to directly measure tire pressure. It transmits pressure information from inside the tire to a central receiver module via wireless transmitters and then displays the tire pressure data for each tire. The system automatically alerts when 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 rotational speed differences between tires, the purpose of monitoring tire pressure is achieved. The indirect tire pressure warning system essentially relies on calculating the rolling radius of the tires to monitor pressure. Introduction to Tire Pressure Monitoring System (TPMS): It combines the advantages of the above two systems, equipping direct sensors in two diagonally opposite tires and incorporating a 4-wheel indirect system. Compared to using only a direct system, this hybrid system can reduce costs and overcome the indirect system's inability to detect simultaneous low pressure in multiple tires. However, it still cannot provide real-time data of the actual pressure in all four tires like a direct system.
