Ok totally weird.

Got in the car and it said TIGHTEN GAS CAP.

Well I have no idea why because it wasn't loose. So I took it off totally and retightened it and still the error was coming up.

So I turned the car off and did it again...STILL THERE.

So I did it again and turned the car off for like 2mins and finally it went away.

Anyone else get this? My "acuralink" said if this keeps happening to take it in because it might be an emission problem!. WTF?

 

I also got a same message. I also knew that the gas cap was definitely not loose. After a few re-starts, the message went away and hasn't come back. I think it was just a hiccup. This was about a month ago.

 

It has not come back yet. It was interesting because I think it had something to do with it sitting in the hot sun that day. I never like to see error messages especially after only 1300 miles!

 

make sure to click it at least 3 times...
in older cars it would end up giving a check engine light code...maybe this was to avoid people freakin out about it if that's all it was.

Try retightening and then reset the ECU by pulling the fuse or the neg on the battery to reset it. Make sure to have your radio security code if you do.

 

That happened to me as well. The gas cap wasn't loose at all. Eventually, the message went away.

 

I had the same problem. The cap was tight but I still had the message. Dealer replaced the cap and no message since.

 

bumping up an old thread as this happened to me today. my tank is 3/4ths full but parked outside the whole day today. nonetheless, it's 55C here so it cant be the heat. it did, however, go away on the third start after i opened and re-tightened the gas cap.

is there a reason why this happens? so far, a search has yielded the following:
a) could be due to overfilling (but then im only 3/4ths full when this happened)
b) change in atmospheric pressure? (eg. direct sunlight)
c) problem with fuel filler neck

has there been a definitive answer for this? if it helps, i just changed fuel from 91 octane 0% ethanol to 94 octane 10% ethanol during my last 3 fillups but was always 0% ethanol prior to the last 3...

many thanks

 

Fuel vapor has to remain onboard the car for recirculation and treatment, so the system has to seal. It's called the evaporation system (or EVAP) and it's part of emissions requirements.

So if the fuel cap doesn't seal, the system detects a vapor leak and throws a "fuel cap" message. Changes in system pressure (solar heating) can sometimes cause leaks past the cap. After tightening the cap, you might have to drive the car a little while before the system is convinced the cap is sealing, and turns the message off.

Or if the cap seal is failed like jbeano's, you'll need a new one.

 

thanks. makes absolute sense when i saw the vehicle outside today (our house faces east and when the sun rises, the rays hit directly on the gas filler door area). interesting post. i guess posts about "topping up" is not true then (Eg. topping up your gasoline can cause tighten cap msg and EVAP system to fail). either way, so far so good, the msg disappeared after 3 starts. but ill make sure not to overfill or park in direct sunlight as much as possible... (though the latter might be harder esp if parked outdoors during workhours LOL)

 

ok updating this and bumping the thread again. the tighten fuel cap msg appeared again last night. so it seems like using fuel with ethanol (vs no ethanol ) was NOT the culprit. the only "similar" conditions i noticed vs the first time the tighten fuel cap msg appeared are:
a) i was parked outdoors, sunlight initially then all of a sudden drastic change in temp (warm and hot to cold and humid/very light drizzle)
b) fuel tank still has 3/4th in it...

i noticed it's been 2 weeks since the last time i had my first tighten fuel cap msg. i am beginning to wonder if this isnt a temporary issue but more a gas cap replacement issue now... any thoughts? the msg may go away again tomorrow/tonight (ive only had 2 start/off cycles afte the latest msg occured) so i dunno what to make of this for now... page 354 of the 2010 manual does tell you what to do if it happens but one cannot keep doing this every 2 weeks, i hope.

 

Mine just came on today, 21000 miles on the car. I checked it and it was tight on. Last time I filled up the car was 3 days ago. Now I have 3/4 of a tank left... Not sure why this is happening.

 

Just am update, it went away the same day... Weird stuff