I've been thinking back to the 605-02 Code. I think you need to do some more troubleshooting of that Code seeing as it's still there. Try this procedure with the 40-pin connector to the transmission control unplugged. 1. From Post #10 above you said that you already checked for a good ground on Pin 2 of the 40-pin connector. 2. I have arrowed four pins (24, 27, 28, & 29) in the 40-pin connector. If you follow the wire from each of those 4 pins it travels up through CONN 13 and to the splice in the Harness Code plug. From there a single wire goes back to Pin 2 on CONN 13, and from there via wire 202-BK to exactly the same ground point as the one service wire 202-BK coming from Pin 2 of the transmission control connector. 3. Connect one lead of your multimeter to Pin 2 of the 40-pin connector. Then connect the other lead to each of Pins 24, 27, 28, & 29 in turn. The result of each one of the four tests should be good continuity. Report your results.