I just dug up some more info about reading codes. Some ECUs don't have an LED to read codes with. This does not leave you out in the cold. Go back to the dash connector that was rewired during the swap and connect the red wires together. This will allow the ECU to flash the malfunction light in the cluster to output codes. All of the wiring tutorials, including the NPM listed above, do not tell you to connect these wires. It will not work without it!