I use VMSPC http://www.silverleafelectronics.com/?q=node/6 It is an adapter that allows you to read many different engines on your laptop for one price ($395 retail). It can be left open while you drive showing a slick glass cockpit type of display on a laptop with most engine and transmission values. It should read most Detroit, Cummins and Cat engines and later transmissions. It will not allow you to reprogram.