Which h/u does this part number belong to on the 900 series trucks.

154940103

Trying to find out if this is the DVD unit or just the Nav. unit? If it is just the Nav. unit, has anyone found a way to make it play DVD's? I.E. stand alone dvd player.

15940102 is the nav unit with the DVD. I have one and it works great, the one you quote is the nav unit WITHOUT a DVD player.