Tire Pressure Monitoring System+, Indirect Measurement System
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2018 Audi S6, 2018 Audi A6 Quattro, 2018 Audi A6, 2017 Audi S6, and 2017 Audi A6 Quattro. However, it is still accessible from the selected car via links, so may be relevant.
TPMS + indirect measuring. There are no wheel electronics installed inside the wheel. With the help of the ABS sensors, the TPMS compares the speed and rolling circumference of the individuals wheels. The loss of pressure is determined indirectly. If there is a change in the tire pressure, then the speed and the rolling circumference of wheel will also change.