Well I got an interesting one in today that I have not seen in years. It has to do with the EGT sensors shorting out or going open and the pcm locking out from starting the truck for 60 min or until it is corrected. This is a unique protection strategy on the 6.4l and there is no indication of this fault in the cluster (no cluster message like the one it shows while engine is running). In this video I show how to get your truck back up and running so you can get it to a shop or home and fix it without a tow bill and how to replace that EGT sensor without breaking it. Hope this helps as this is often a misunderstood no crank concern.