Calculation of Vehicle Position
WARNING: This page is about a different car, the 2008 Acura CSX, 2007 Acura CSX, and 2006 Acura CSX. However, it is still accessible from the selected car via links, so may be relevant.
The navigation unit calculates the vehicle position (the driving direction and the current position) by receiving the directional change signals from the yaw rate sensor and the travel distance signals from the ECM/PCMs vehicle speed pulse (VSP) signal.