When you say a high end computer will somewhat communicate, are you referring to an aftermarket scan tool like the Snap-On Modis or the Solus or the MAC Determinator?
For the Chrysler computer, are you trying to connect the WiTech or the StarScan to the truck and it will not communicate with the Cummins ECM at all?
When the "high end" scan tool connects and communicates, what are you able to see once in the ECM?
Are there any DTC's set or are you even able to get that far?
When you turn the key on, do you hear the lift pump in the tank power up and make the buzzing sound?
Is you SKIM lamp flashing in the instrument cluster?
Does this truck have a tuner installed?
Does this truck have the original ECM bolted to the side of the block?
