Got a 01 durmax in the shop for a crank no start, its got a new filter head, new cp3, new injectors within the last 10k miles and a new frp sensor, we have bled the system and nothing, the frp is desiring 42-45 mpa and the actual is stuck at 2 unless you unplug it which makes it around 180mpa, we’ve tried a known good ficm and that didnt fix it, ecm/ficm fuse is good, we tried the return test out of the main return line and it only had 50 milliliters which check it seeing as each bank say 12 mil each with cp3 using 20 roughly and the truck wont start at all, possibly ecm? It will run off old cosby juice but thats it, any info or thoughts?