2006 International 4300 dt466 running rough and dying intermittently

I have a 2006 international 4300 with a dt466. Also Allison 2000 series. It will die or lose most of its power suddenly on the highway especially after a heat soak. If you clear the codes it has good power for a while then dies. When you restart it it has low power again.

I have a hand full of codes

421-426 injectors 1-6 low to high open

454 cylinder 4 injector shorted to ground or b+

332 ICP above spec engine off

125 ICP signal out of range high

113 electrical system voltage B+ out of range low

312 EOT out of range high

135 idle validation switch circuit fault

525 injector driver circuit fault "M"

It also seems to have a erratic ICP pressure when running badly/lopes.
Top of the range is like 6000 psi. Is it even supposed to got that high?!?


This is from servicemaxx all codes were inactive even right after it happened.


Do all of those sensors feed into the idm? Am I looking for an idm issue? Just looking for insights and hopefully a place to start from.

Also according to fuel pressure sensor it has good fuel pressure. ~60 psi

 

I load tested with a halogen bulb the powers and grounds at the idm directly to the battery and they all lot up brightly and equally. Sorry for the slow response I'm super sick so working on things stinks right now. Could it be a power board problem or a idm itself? What other wiring should I check?

 

Zero psi. It seems something is freaking out the ecm/idm intermittently. Normally the icp is fairly normal.

 

I also followed the wires from the batteries up to where they entered the harness up by the firewall. I also load tested the wires and they all lit up brightly while maintaining voltage.

 

Okay...

I'm super sorry for the long wait. We are currently moving to across the country to Montana. I have been incredibly busy and haven't had time to do anything meaningful on this truck. However, I have now installed a IDM from a 6.0 powerstroke and had it reprogrammed. (Fun fact, it works.)

It sure feels like it has more power. Runs better, a general improvement. I also installed a IPR valve. Genuine International. Set me back almost 600$ from the dealer. (Oof). Anyway as I was test driving it and also grabbing some sheetrock (Overkill I know) The CEL came on for a few seconds.
Truck did not shut down as far as I can tell. If it did it was fast enough that it wasn't obvious. It has now set these codes.

 

As a side note, it also appears oil is pushing/wicking into the harness and into the PCM connectors.

After studying the wiring diagrams graciously sent by Inderjit, I am wondering if I am losing my reference ground. (*Vref A and B). I am wondering how best to test this or, if I am going completely the wrong direction, where I should be looking.