I'm still wondering about the CPS. I had one a couple of months ago that did somthing similar, but didn't exhibit the usual signs of a CPS. Turned out that was the problem. The only difference is there was smoke. I know it's not much to go on. But a good way to rule it out.
And also not every scanner will communicate with thease trucks. About the only thing they share is the obd2 plug. Other than that how they "talk" is not obd 2 friendly. If you could find auto ingenuity (plugs into a laptop) or a scanner you know will talk to thease trucks it's hard to get anything out of them.