Jeep cherokee

hey team i have a 1999-jeep cherokee, 4 liter, 6cyl. the check engine light cane on.about three week ago.i had advance auto,scan it.there was not a code.the truck run find.so using the scan tool.he cut the light off.it has not come back on.any idea while light would come on,with no code.

Get someone else, maybe with a more sophisticated scanner, to scan it.
If it really lights the CEL with no code then it might be a problem with the computer itself.
You can get away with that if your state doesn’t have emission inspections, but what if a “real” problem crops up and you’re ignoring the light?

I not sure about Jeeps but I know in Chevys if the gas cap is not on corectly or missing it will set off the CEL and when the gas cap is put on tight enough it will clear itself after a short drive.