I just bought a 2005 highlander limited from a toyota dealership. It came with this navigation unit.. when i start a route the lady says go to the point and navigation will begin or something to that effect.. but after that i never get any voice, turns or anything.. one time i go to the location and she said arrived.. what can this be?? the voice is on the volume is up? the map goes off location many many times until i reset it with the change tire option. Still no turn by turn directions at all.. any ideas?