If you open the pro driver up ( 4 little screws), and remove the keep alive battery for a minute, then it resets the prodriver to 0 odometer. You can program in any number you want.

If you hook up a DDEC reader, you will see the odometer kept by the DDEC computer. It is not resettable, and will count from when it was installed new.

Neither is guaranteed to be the chassis mileage though.