Tighten Fuel Cap Warning Light Stays On

[jetdoc]

I had same problem, tried tightening 3-6 clicks over four days, no luck. I used vasoline on large o-ring on cap it self. Light went off on next drive. (that was six tanks of gas ago and four weeks ago ! ) try it !

[Cobra]

As I posted earlier this happened to me a couple days ago. I saw a posting from 'jetdoc' that he applied oil (valvoline) to the fuel cap o-ring. I took this a step further.

I took the cap off and noticed that the top lip of the filler neck seemed a bit 'rough'. So I 'polished' it a little with gray scotch-brite. Then I rubbed a very small layer of oil (mobil 1) on the lip I just polished. (the o-ring on the cap is recessed in and I thought a little to difficult to get just a little oil on easily).

Then I put the cap back on (one click). Started the vehicle, the '... tighten..' message flashed for a split second and then was gone.

This was my experience. It might be worth a shot.

[VoicesInMyHead]

Originally Posted by Cobra

...I took this a step further. ...Started the vehicle, the '..tighten..' message flashed for a split second and then was gone. This was my experience. It might be worth a shot.

Interesting. I had this message for 10 days and through 2.5 fill ups, a little while back. I may do this as a preventative measure for the future. Thanks for the suggestion!

[JRohe]

I had the same thing happen with just 1800 miles. The problem started Friday on my way home from work. So when I got home, I opened the gas cap, re-tightened 6-7 clicks and it remained on...so I tried again...same result. I even turned the vehicle off, then back on...same old story. I parked the vehicle over the weekend and today (Monday), then message is gone. Don't know what happened, but time seems to heal the problem.

[Pug]

Originally Posted by mugen1

Now, for those of you who have the Scangauge II, can you use it to reset the fuel cap warning light? Did I ask this question before? ...

16,000+ miles and 30 months later I get the warning!

Originally Posted by HondaTech

There is no sensor for the fuel cap. The evaporative emissions system runs a self test every now and then to make sure fuel vapor is not being leaked out into the atmosphere. Fuel vapor - the gas smell you know so well - is actually unburned hydrocarbons, an unwanted and restricted emission gas. The evap system consists of various valves and solenoids as well as a vapor canister, the fuel tank pressure sensor and the fuel tank. The idea is that the fumes from the gas are introduced into the intake manifold to be burned, rather than going free into the atmosphere. The vehicle will run it's tests when certain enable criteria have been met. It opens and closes the valves and solenoids and monitors fuel tank pressure sensor voltage. By monitoring the pressure changes, it tell if the evap system is leaking... or letting fumes out when they should be sealed in. It uses the rate of leakage - expressed to the ecm/pcm as a voltage change over time, to determine the size of the leak. The ecm/pcm then uses logic to determine what to do - set a DTC and a "check engine" light.... or simply warn the driver that the fuel cap might be loose. When you re-tighten the cap... the message will stay on. It will remain on until the evap system undergoes another self check. This could take a few starts, or it could take a week. It depends on how the vehicle is driven. If all you have is a check fuel cap message, tighten the cap and wait for it to go away. It will go away when the system runs its next self check. If, when the system self checks, it finds there is STILL a leak... instead of resetting the Check fuel cap message... it will store a DTC and the MIL will illuminate. (MIL = malfunction indicator lamp) Then it is time to head to your local friendly Honda dealer and get it checked out.

HT

I was going to investigate the Scangauge reset until I read HT's explanation. I don't ever remember seeing the "Check Fuel Cap" warning before... I s'pose I'd remember if I did.

Being there is no DTC thrown, I'm assuming there's nothing to clear.
I'll just have to wait patiently (while resetting the display after each startup), and if there is no further reason for it to be on, it will eventually disappear.

Weird that it appeared three days after filling-up, though. And it might take awhile for it to go away... I only plan to take my normal 6 mile commute to and from work in the coming week, so the "auto-reset" when the system decides to self-check may take awhile.

Thanks for the detailed explanation.
Saved me some time.

[flathead]

I've a new twist to add to the ongoing saga. This has happened to me also, but it ususally resolves with a re-twist of the cap or the next fill-up. The dreaded message came up again about 3 weeks back and just wouldn't go away no matter what I did. I figured at the next service, I'd have the tech look at it.

Behold this morning when I left work with the air temp at 42F @ 7AM (IN AUGUST!!! ), the message was gone. Go figure

[FTM1]

Originally Posted by flathead

I've a new twist to add to the ongoing saga. This has happened to me also, but it ususally resolves with a re-twist of the cap or the next fill-up. The dreaded message came up again about 3 weeks back and just wouldn't go away no matter what I did. I figured at the next service, I'd have the tech look at it.

Behold this morning when I left work with the air temp at 42F @ 7AM (IN AUGUST!!! ), the message was gone. Go figure

I have said it may have something to do with Temp change when it runs its check not sure. I think the 2 times we had the message the Temp had changed. But the Temps change all the time so that might not even matter.
The light goes off by itself & shows up when it wan'ts to no dealer service required. If it comes on & stays on longer then a week I would make the trip to the dealer.

[Pug]

Just an update...
My RL's "Check Fuel Cap" message went away with my last startup while leaving work tonight.
I forgot to check the mileage and fuel usage of that tankful of gas up to that point , but can get it when I get back into the truck.
For those of you wondering, the temperature outside was 61 degF when I started the engine and noticed that the message had disappeared.
The "reach and push RESET routine" had almost become a reflex action by this time.
I'd like to record the fuel usage and mileage on that tankful of gas to compare if this ever happens again, so I'll try to remember to get the numbers before driving off tomorrow.