You need to stablish communication with the vehicles pcm first. Try connecting
manually, if no connection look for missing power and grounds to the pcm or another
module shorting the bus line like the abs, disconect it from the network and try
communicating again. make sure the check engine light comes on, if not that's a clue
of bad pcm or no power or ground getting to it. you will need a wiring diagram of the
vehicle to figure this out good luck.