Yaw is the motion of turning pure left or pure right.
I wonder if that yaw rate thingy is a G force meter..
i mean, the car already has accelerometers for the VSA. IT can easily output the reading from those accelerometers.
Just a wild guess..
edited:
check this site out. Maybe Honda senses where the car is going by sensing the g forces and speed. So the nav stll "kind of " work when GPS satellite reception is bad.
Vehicle control system using navigation system steering - US Patent 5928299