Fuel Cap warning light

[SuperAvant]

This light just came on on my way home to work. My center display tells me the fuel cap is missing or is not on correctly which of course that isnt the case. I believe this works on a vacuum system so maybe I have a gas leak? I dont smell gas at all however...

Any thoughts?

[charliemike]

Ze Germans, they over-engineer everything don't they?

Light to say the gas cap is off? How awesome is that?

[SuperAvant]

Anyone else help? whats the best way for detecting a fuel leak? Maybe the fuel vapor hose?

[40valve]

Maybe the fuel vapor hose?

That's what I was thinking but you would be throwing a code for that and smell the gas. I does sound like you are losing pressure somewhere.

[SuperAvant]

Anyone got any tricks for finding a leak? I wonder if the vacuum seal is only for the tank or the entire fuel line system...

[wkornfeld]

My only current trick is to take it to the dealer....

[szinkuti]

so u have a light on that says your fuel cap is not on?.....or you have an check engine light on with the fault that says you have an evap leak?...alot of times you will yank the fuel filler out of your neck when u fill up and it catches the metal and bends it out...then when you put your fuel cap back on..it doesnt see it there...look at the neck with the gas cap out and look at where the gas cap would be...and see if the metal on the neck is not perfect...like a possible little hump instead of smooth....if you had a fuel leak...the check engine light would come on.....so check your filler neck where the cap would be..i can take a picture if you need one of what im talking about...

[steveo_01vwgolf]

pic please, think i'm having this problem. getting evap leak warning and i took it to the shop, they looked and can't find any leaks.. pic please... thanks..

[GameBreaker]

Did you recently fill your car or was there a decent temperature change? This occurs when you turn on the car and the gas cap wasn't properly tightened, or in the rare occasion a large drop in temperature when the gas cap was partially tightened. Basically it is just an automated check to make sure the proper pressure is maintained on the seal. I would suggest retightening the gas cap while the car is off, and give it about a day, usually the problem will correct itself within a day. If not, check for codes or take it in.

[Eddie Man]

This happened to me a few weeks ago and I was saying WTF...
It happened right after fueling and I did indeed place the filler cap on correctly.
I believe what happened was during fueling, some sort of air gap got into my system and then subsequently, triggered the CEL...
The bitch of it was that the CEL remained on for a good day and a half.
After that, no issues.

A believe what happenned was that I was cleaning my windshield, completed pumping and didn't put the fuel cap on till I was done windshield cleaning.
Maybe that was the issue but who knows.

My suggestion is to check the cap and give it a couple days.

[GameBreaker]

D'oh, I forgot to mention one very important thing. When you guys were doing this, by chance did you have your cars running at the time, perhaps to stay warm? At fillup, BMW, Mercedes, and Audi all have the same issue where you have to make sure the car is off while you fill up the tank. Otherwise, if the car is on during fillup this is what normally causes the problem.

[40valve]

D'oh, I forgot to mention one very important thing. When you guys were doing this, by chance did you have your cars running at the time, perhaps to stay warm? At fillup, BMW, Mercedes, and Audi all have the same issue where you have to make sure the car is off while you fill up the tank. Otherwise, if the car is on during fillup this is what normally causes the problem.

People that have cars running while filling up should be punched in the throat

[SuperAvant]

My light went off. It wasnt the CEL but rather the display in the center dash (that comes on if you have a door open) that told me my gas cap wasnt on. It hasnt come back some I am a little confused on why this happened.

[nimski62]

My light went off. It wasnt the CEL but rather the display in the center dash (that comes on if you have a door open) that told me my gas cap wasnt on. It hasnt come back some I am a little confused on why this happened.

Didnt even know we had such a feature, for me in my past cars, the CEL comes on if the fuel cap is not tight.

[Mooneywa]

This happened to me. I took it to the dealer and they had to replace the "fuel door sensing switch" and associated circuitry, wiring, etc. They had to take out the back seat and it was quite an ordeal from what I gathered. I can look into it more if necessary.

[0302]

People that have cars running while filling up should be punched in the throat

I agree

This situation also happened to me. I replaced the gas cap with a new one and didn't happen again.

[SuperAvant]

Came back again. It appears only to happen at idle and in bad weather...So weird.