I hava a 2005 sut hummer engine light came on once I check my gas cap and the light went off,it's been at lea

I hava a 2005 sut hummer engine light came on once I check my gas cap and the light went off,it's been at least a month and now and the window on the dash say check gas cap I did but the engine light is still on I changed it and the light wont go off don't know what the deal is now.I hava a 2005 sut hummer engine light came on once I check my gas cap and the light went off,it's been at leait probably is indicating a fault somewhere in the fuel evaporative control system. See a technicianI hava a 2005 sut hummer engine light came on once I check my gas cap and the light went off,it's been at leaTake it to either the dealer or a mechanic. Sometimes the gas caps don't have the correct seal. They will put it on a machine which will tell them why the vehicle is sending off the signal. If it is a computer error the machine will clear it and you should be fine. If it comes back on take it to the dealer and inform them of your situation. If you can't afford it you can buy a new gas cap and have them clear it again. If it comes on again then you better get it checked out..