Sorry! I'm not very good at English.
I have a problem, periodically turn on the lamp "check fuel cap".
fuel cap-normal.
What reasons can lead to the inclusion of this warning light?
Sincerely SERGE13
Ford Explorer 4.0l XLT 2000

 

the system under the hood has a small vacuum on the breather line from the gas tank. if gas tank cap is loose, or tube from tank to engine is broke, or rubber boot connectors cracked--- all will loose vacuum. ...Look at hoses and clamps on fiiler neck to gas tank

 

Thanks Steve (ill)!
I checked all the fuel system, but the fuel leak was found.
Odor of fuel, I do not feel.
I tightened the clamps.
Signal Check Fuel Cap still there

 

Thank you all.
Signal "check fuel cap" No!
I had a bad fuel cap
The fuel tank is not a vacuum.
Now all O. K.