It could be nothing like a fuse.....or...it could be a serious network problem.
Sounds kind of ominous and sounds like some critical details are missing. Not something you normally see posted in car for sale ads.
It is not a normal known failure issue with those cars. (....Escalades are known for this if a penny gets in the cigarette lighter socket and blows the fuse...).
I personally would have a mechanic look at the issue and see if it can be quickly resolved. If not a quick and easy fix....I would walk away.