Check fuel cap

[Tommyva]

Check Fuel Cap Message

Just out driving and the Check Fuel Cap message comes up along with an icon on the dash. The truck runs perfectly. No check engine light at all. Any idea what causes this message?

 

[MADDOG]

Usually, it's a loose cap or possibly a cap with a defective seal.

 

[Rlaf75]

What that means is there's an EVAP leak somewhere in the system. The most common and least expensive fix is a new gas cap. Filling the gas tank while the engine is running is also a common issue. The light may not come on for a few times but it will eventually. I'm not saying you do that but if you do then stop. Like I said, a gas cap would be the least expensive part to replace but you'll still probably have to check it on a scan tool and clear the code(s). If you replace the cap try to get a factory cap or a good name brand aftermarket and clear it and keep driving it. If it comes back on then further diagnoses wil be needed.

 

[Tommyva]

Well a few days later the check engine light came on. I replaced the purge valve mounted on the tank. $20.00 part and it took longer to get the truck in the air than it did to replace the valve.