I would take a second look at the ALDL wiring. The '8625 only uses 3 wires to the ALDL; pin A, pin B, and pin M. Remove the unused wires from the ALDL.

It sometimes causes confusion with scan tools, select a 1993 '8625 $E6 vehicle by make / model / year / engine / trans. For example 1993 / GMC / K1500 / 5.7 liter / 4l60E Vin code K. The vehicle you choose might need to be different if your using $OD, $OE, or $31.

dave w