[Ron Nielson]

Get the truck back to your house and to safety. See if there are any codes stored. Ensure the batteries are fully charged and the cables are clean and tight.
Download the electrical manual for your truck here https://www.gmupfitter.com/wp-conte...Builders_Manual_Service_Manual_2016_en_US.pdf Lots of good information in this.

Am I correct that your fuel filter pump is now hard after pumping? No air coming out of the bled screw? Does the engine crank over but not start? Is your check engine light on in the dash? If so, get the truck scanned for codes. An inexpensive reader tool that will read and clear various codes is a great tool especially when there is no other information. I keep one in each of my cars and truck all the time.

 

[Ron Nielson]

The only code that stuck around is p128e.

Go here // on edit//TSBs (Technical Service Bulletins) for All Years, Makes and Models
// on edit//
and enter CHEVROLET and P128E

 

[Ron Nielson]

I hope you replaced the o-ring under the bleeder screw. If it fell out and you didn't know it was there, it may still be missing. Did you do the fuse check you mentioned earlier? Easy to do with a test light and will take less than 15 minutes.

Mobile mechanic, if he has some experience with the Duramax, might be the best thing to do.