Hello
i have unknow trouble with it , a have speed impuls and rear gear connected , wenn i open a 3d state display , i can see a speedpulse ( the counter is o.k) but the distance (km or Mile) 0.00 , i can drive a 20 km and a Unit dont make any progress by turn's a have tried many times with total reset of the unit , and with only reset calibrate ,and with take a Unit away from car , and one time from 5 or 10 distance run's and i can calibrate the Unit with in 5 to 8 km.
It "see" a turns and so on and 3d-Hybrid appers ,but i don't not understand , what i must to du that distance run's . It's probably a Ghost in it 
Can anybody explain to me , how it must work ?
I make the same things , and one's it run's and another 5 time not
Sorry for my bad english