Just scanning the service report,
1) Codes reported by car.
2) Some work done? But it is cool the Tech admits he has not had the training or taken the time to call for support !!
3)R/R=Remove and Reinstall. Let's hope he actually laid hands on each fuse and reseated it. He says he tested resistance on two wires.
The Tech's thoughts on the cause of failure or what fixed it?
5430922 CONNECTOR RECONNECTION
In aviation this would be written up as: Reseated LRU. System ground tests good. (Line Replaceable Unit)
In their defense, You can't fix it if it isn't broke.
It sounds like they fiddled with all (?) the 14 V bus fuses and a few connections, then it started working.
'14 Spark EV 2LT w/ DCFC. 85k miles.
'17 Bolt Premier w/ It All! 53k miles.
GM needs Modern Troubleshooting tools for Modern EV's.
3 step Trouble Tree, 1st try, nope, 2nd try / cost $800. 3rd try fixed it.