Sensor Function Using Pressure Increase/Decrease method
WARNING: This page is about a different car, the 2004 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
Each sensor takes a pressure measurement sample once every 20 seconds while in stationary mode. If the tire pressure increases, or decreases by more than 11 kPa (1.6 psi) from the last pressure measurement, another measurement will occur immediately to verify the change in pressure. If a pressure change has indeed occurred, the sensor transmits a re-measure mode transmission. When the antenna module receives a re-measure mode transmission while in TPM learn mode, it will assign that sensor's Id to the location on the vehicle relative to the order in which it was learned.