I'm beginning to tbink on the same line as edwardt with it being battery related.
Sometimes low battery voltage can cause the control system to code out different codes, usually several at a time. And now that you come back and say it improved when water was added is a tell tell sign of battery issues.

I'm curious how much he/you had to add?
If it was alot like 3 to 5 gallons or more then in my mind theres no doubt about the battery being the cause.

I'm sorry i didn't ask you about the battery to start off with because in normal troubleshooting on electric trucks that is the first thing that is always checked.
I saw the codes you posted and just jumped right into that thinking it might of been a switch or circuit problem.