Hello all!
I am currently swapping a 94 6.5 Turbo Diesel in my GMC sierra 1500. The truck had a blown on the crank 6.5TD. The engine is currently in its place but some plugs of the wiring harness are now useless since the former 98 engine is EGR and the 94 isn't. Will the ECU allow the truck to run if it miss data or do I need to transfer all wiring harness + ECU to turn the truck from OBD2 to OBD1?

 

Swap things the other direction-make the 94 like the 98 was.
Also check the # on the 94 IP-if it ends in 5068,you will need to swap the 98 IP over also.

 

I found a complete ECU + complete wiring till ALDL connection for cheap so i'll just swap it OBD1 so I can tune it easier. I'll post here what will happen .
GMTDScan Tech will be on the way soon.