I have no hard codes set and the truck runs fine, however if I run a buzz test on the truck it will return a p1668. Now, I know that this codes means there is a communication problem between the IDM and the PCM and I have found a few mentions of chasing grounds and wires in the harness between the two. WHat i don't have is any information as to exactly what wires, colors, locations, anything to get me started. Does anyone have any information where to start on this one? I am a pretty capable mechanic but I think some better resources would be helpful on this one, especially if it is just a bad connection and not a broken wire or something.
Also, does anyone happen to know if this code specifically identifies what the communication problem is or what "communication" it is looking for. Not so much for troubleshooting (although it may help) but because I am wondering if it could cause minor problems and I'm just one of those people that like to know how things work.
Thanks guys, the .org hardly ever fails me.