Check Fuel Cap light

On my 2003 Ford Explorer Sport, my Check Fuel Cap light came on and stayed on even after making sure the cap was on secure. It wasn't until I disconnected the battery for 10 minutes that I was able to reset it. Can't understand why the system is designed that way. I heard that it takes up to 10 drive cycles to reset the light. Is this a ploy from Ford to get you to take your car in for servicing????

Jim

Reply to
Jim Johnston
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Hi Jim,

I had something similar happen on my '97 XLT a couple of years back.

At the time, the dealer asked me if I sometimes left the ignition in the 'accessory' position while I was filling up (I do, as I often leave the radio on to listen to while refueling.)

He claimed that there is a sensor to detect a vacuum leak in the fuel tank, and that by leaving the ignition on (even in 'accessory') while refueling could trigger this.

Not sure if this is a known issue, or whether the dealer was just feeding me some lame excuse, but since then I've always left the ignition completely off while refueling, and the condition has never reappeared. Oh yeah, I seem to remember that the dealer corrected the issue by replacing the fuel cap, which was about an $18 part. Again, not sure why this would be needed, as it seems likely to me that the sensor wouldn't be in the gas cap, but...

Hope this helps.

Reply to
Steve Reppucci

I believe it's just one of the many federal requirements for emission control. If you don't have a cap you vent gas vapors. So they require the computer test for that condition.

Reply to
AZGuy

The sensor is not in the gas cap (don't know where that idea might originate) but there are valves in the gas cap that are prone to leaking.

Additionally, for those states with emissions testing, there is a requirement for emissions related codes to remain in history in order to foil those that might try to usurp the testing regimen.

We must remember that cleaner air isn't a cash grab by anyone (though cleaner air doesan't come cheap)...... it's a growing concern in many well populated areas. Indeed, for those living in the Los Angeles basin, it is all ready a major concern with other urban settings joining up fast.

-- Jim Warman snipped-for-privacy@telusplanet.net

Reply to
Jim Warman

The most common leak found in evaporative systems is a loose gas cap, hence, Ford is trying to prevent (underline that) you from taking your car to the service station by signaling you to tighten the gas cap and fix it yourself. The more money Ford spends on warranty service the less profit they make.

Ten drive cycles are not required to reset the light. If the MIL is lit, it will take three drive cycles to turn it off. I believe the check Fuel Cap light will turn off it one trip. Now here's the catch...You must drive the car is a specific manner to meet all the conditions necessary to run the evaportive leak check. Most of the time our everyday driving conditions do not meet the required conditions for the evaporative leak test. For example, it takes about a month of driving my normal routine for the system to run an evaporative leak check on my truck, and I take about four trips in a day. Let's see, 4 times 30 equals 120 trips to turn off a Fuel Cap light. However, if I knew what conditions were required to run the test I could turn the light off in just one trip (i.e., cold start, stable cruise at x mph for y seconds, etc.).

As you know, you can turn the light off by disconnecting the battery. But, if the state you live in has a smog check program and they're checking the computer system, you will probably fail the inspection if you've recently disconnected your battery to clear fault information.

Tom

Reply to
Tom

Here in Chicago if you've got a newer car all they do for the emissions test is plug into the diagnostic port. Much better than a couple years back when the put your car on a dyno!

Reply to
JaWise

Hope you aren't afraid to have your car on the dyno as the still do it here in the fine state of Illinois. After the fuel cap is inspected for vapor leaks they hook it up to the diagnostic port and then roll it onto the dyno.

Reply to
Sustang

Anyone here from California? I'm led to believe that their's is one of the most stringent programs to pass.

-- Jim Warman snipped-for-privacy@telusplanet.net

Reply to
Jim Warman

My 94 Explorer gets tested every other year. They use a dyno to test with a sniffer in the exhaust pipe, and it's connected to the DMV computer so the results are recorded immediately after the test. You do get a copy of the results.

Reply to
Mike Iglesias

It depends on the year of the car. If you have a newer car they just plug into the OBD port. If it comes up ok your done.

Reply to
JaWise

OK, here's the next report on my Check Fuel Cap light. After I disconnected the battery everything cleared up for a few days, then the Check Engine Light came on. Two days after that the Check Fuel Cap light came on. So now instead of trying to reset it myself, I took the car in for servicing. Ford plugged into the module and read a "Minor Emissions Problem". They ran a vacuum check on the cap and fuel tank and everything checked out OK. They reset the light and then ran an Evaporative cycle on the system and no warning light. I have driven it two days now and everything seems OK. The maintenance guy at the dealer said he had seen alot of these since Ford when to the new Fuel Cap.

Jim

Reply to
Jim Johnston

Here's the latest and I need someone's advice on how to proceed. Both Check Fuel Cap and Check Engine Light are back on. I tried buying a new fuel cap (Stant) and have driven it for a week now making sure it is on tight and the lights will not go off. I haven't disconnected the battery. I want to take it in to the dealer, but I am afraid they will do the same thing as last time ... nothing!!! How do I convince them that there is another intermittant problem and that I'm not leaving my gas cap off????

Jim

Reply to
Jim Johnston

Turns out that this problem is caused by overfilling your gas tank, usually in the summer and not driving it afterwards. The gas expands and overflows into the EVAP canister. They found the canister filled with fuel. Lesson learned ..don't overfill past the normal cutoff on the pump.

Reply to
Jim Johnston

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