2001 Aurora-Check Gas Cap Warning

Since a recent fill-up, 5 days ago, the "Check Gas Cap" warning comes up with every start-up. Hitting reset makes it go away until the next start-up. The gas cap is on and tight. Anybody know how to make the warning go away permanently?

I have no firm knowledge of this problem but the first thing I'd do is try a new GM cap. The fuel system should be sealed.The cap has a one way valve in it that lets air in but no fumes out. It may be stuck causing vaccum to build up in the tank. You could try loosening the cap after a drive and listen for the pressure equalizing which would show the valve isn't working.

Thanks for responding. I guess patience is a virtue. The next time I started the car after posting, the warning stopped coming up. It must clear itself after a number of starts.