Detroit throwing me for a loop

Working on a 91 Volvo with a series 60 Detroit ddec II. Initially the truck ran 30 seconds an died, swapped out the coolant level sensor and the truck ran great for half the day and died completely. Traced it to a fuel line and repaired only to have a return problem of running 30 seconds before it died out again. Checked the oil pressure sensor and found the harness bare and wires crossing. Patched the wires and truck ran great, for about 3 hours before diving and refusing to start. Towed it to the shop and after some searching found bad batteries. Replaced the batteries and the 30 second run time issue reoccurred. Pulled the wire harness to the sensors and repaired several questionable wires, and the problem continued. Replaced the oil pressure switch and no change. I’m out of ideas, can anyone point me in a new direction? Any help appreciate, thank you.

 

I’ve checked the pigtail and it’s good, unfortunately the ecm has several codes stored in it and my scan tool is out for repair so I can’t clear them to see what comes back, but I’ve checked both the oil and coolant sensors and repaired the harnesses and replaced both sensors. The truck still keeps shutting down like it’s sensing a problem.

 

Pulled the power supply harness to the ecm and cleaned all contacts, as well as broke down the other wire harnesses (except the injector harnesses) and checked each wire in them, repairing damaged wires. Here’s a list of codes 12, 14, 16, 34, 35, 36, 43, 44, 45, 46, 54, 58, & 61. Not sure which of the codes are still active and what is stored