"CHARGE SYSTEM FAULT"
My 1999 C5 coupe (built 8/98) displayed repeated "charge system fault" messages when starting. The dealer mechanic was stumped and called Chevrolet Technical Assistance. He was instructed to check ground locations on and near the starter (below the battery tray). He found several nuts that were loose on ground studs, with corrosion present (not from a leaking Delco battery acid - that happened later).
He cleaned the locations and tightened the nuts on the studs. That eliminated the DIC messages. The mechanic said Chevrolet Technical Assistance immediately knew what the problem was and said it was a problem with the new car assembly (the nuts were not tightened properly).
My car was built after the infamous UAW strike. I'm not sure if the improper assembly was intentional or sloppy work, but apparantly there was enough of a problem for Technical Assistance to investigate and determine the problem.
I saw on your profile that your C5 is a 1998 - is it a "late build"? Mine was one of the first 1999's built - in August 1998.
Good luck - I hope this helps.












