That was a bust. Didn't fix the problem, so on to chasing the wiring I reckon.
Thanks Rawze, I'll do that. After reading what you guys seem to be able to do, I like that option.
Since I don't want to leave a thread unresolved, if simply for future reference, here's what happened.
Apparently the truck was throwing a code for a "Speed Sensor" issue when it was shutting off. The company mechanic who had been working on it dismissed it as a fluke... because he'd taken 2 used ones off another truck in the fleet when they had gotten ready to sell it to my friend. After our computer experiment failed, he revisited those sensors. Replaced one on cam, I think, and one on transmission. Truck has worked 3 days straight with no issues. Sometimes it's the simplest things I guess!
thanks for following up for everyone.
Cam sensor. Will shut off like its ignition switch problems. Thanks
(07-15-2017 )Magard Wrote: [ -> ]Cam sensor. Will shut off like its ignition switch problems. Thanks
Usually you will get a lot of alarms for cam/crank position sensor failures along with the shutdown if they are failing. I didn't see where he mentioned he was getting any alarms, just truck shutting off. Nonetheless, it is always a good idea to check the ecm for fault codes whenever it shuts down.