"Check gas cap" purgatory

[CaptOchs]

This issue won't go away! It comes back right before state inspection too!

I have a 2013 Big Horn. Over a year ago I got the evap leak CEL / gas cap. I was able to resolve it by buying a new gas cap (at Autozone) and sanding the rust off the filler tube. It came back a few months later, but I sanded it down more and it went away. Last July I had the fuel tank straps replaced by a recall. Last month the CEL came back with an evap leak / gas cap. I took a look underneath and the fuel filler line was rusted pretty bad. Since it has obvious rust issues I replaced the fuel filler neck. I put all new water clamps on too. I reset the CEL with my ELM scanner and the codes went from "pending" to "historical." The CEL light is off, but the gas cap message still displays. I drove around for 45 minutes at different speeds. I heard some genius thought these codes best remain until the computer is certain the condition no longer exists. I thought about buying an OEM gas cap to rule that out, but the dealer wanted $58 for a gas cap! My state inspection is due again an although the CEL is gone the gas cap light is on.

Not sure if anyone else has gone though this. If the light doesn't go away soon, I will probably be forced to take it in. Thoughts?

 

[Daw14]

Petroleum jelly on the cap gasket may help , also so many engine cycles may have an effect.

 

[EdGs]

Mine turned out to be the esim.

 

[PA Ram]

Mine turned out to be the esim.

2nd this, mine was also the ESIM.

 

[stenerson]

In my case it was the Evaporative Emissions System Leak Detection Pump. Is that the same as esim?
21 dollar part at Amazon

 

[Sherman Bird]

This issue won't go away! It comes back right before state inspection too!

I have a 2013 Big Horn. Over a year ago I got the evap leak CEL / gas cap. I was able to resolve it by buying a new gas cap (at Autozone) and sanding the rust off the filler tube. It came back a few months later, but I sanded it down more and it went away. Last July I had the fuel tank straps replaced by a recall. Last month the CEL came back with an evap leak / gas cap. I took a look underneath and the fuel filler line was rusted pretty bad. Since it has obvious rust issues I replaced the fuel filler neck. I put all new water clamps on too. I reset the CEL with my ELM scanner and the codes went from "pending" to "historical." The CEL light is off, but the gas cap message still displays. I drove around for 45 minutes at different speeds. I heard some genius thought these codes best remain until the computer is certain the condition no longer exists. I thought about buying an OEM gas cap to rule that out, but the dealer wanted $58 for a gas cap! My state inspection is due again an although the CEL is gone the gas cap light is on.

Not sure if anyone else has gone though this. If the light doesn't go away soon, I will probably be forced to take it in. Thoughts?

58 dollars for a gas cap on a 50-75,000 dollar truck. I wonder if jumping over a dollar to save a penny is REALLY worth it! Get the OE, or have chronic headaches.... or you could have it properly DIAGNOSED! What a novel idea!

 

[CaptOchs]

In my case it was the Evaporative Emissions System Leak Detection Pump. Is that the same as esim?
21 dollar part at Amazon

Seems to be pretty common!

 

[CaptOchs]

58 dollars for a gas cap on a 50-75,000 dollar truck. I wonder if jumping over a dollar to save a penny is REALLY worth it! Get the OE, or have chronic headaches.... or you could have it properly DIAGNOSED! What a novel idea!

Actually it was a $24k truck bought 5 years ago used. It's a 2013, over 10 years old!

I did take it in to have it fixed last year. I pulled into the shop with the CEL light still on for an evap leak. The mechanic pulled it into the shop and the light was off. He cleaned up the filler neck because of rust and checked the gas cap. It all looked fine so he recommended changing the cap if the issue came back.

The filler neck is pretty cheap and only 3 hoses. Easily done. The CEL is gone so it may have fixed the issue if only this gap cap light would go away.

 

[EdGs]

In my case it was the Evaporative Emissions System Leak Detection Pump. Is that the same as esim?
21 dollar part at Amazon

Yes

 

[stenerson]

Seems to be pretty common!

Yeah. I bought a new aftermarket cap and smoothed the rusty area top of filler neck where it sits. The old gas cap was a little loose when tightening up. But the gas cap light issue didn't go away until I changed that ESIM. Personally I'd try replacing that before taking it to a stealership.

 

[62Blazer]

What code is showing up with the scanner? I can't imagine a warning light on without showing a specific code?
Keep in mind that the system is detecting a small evap leak in the fuel system. The gas cap comes on because that is a common issue (people forgetting to put it back on after fueling, etc...). However there is no specific sensor that knows if the actual gas cap is on or not, it only senses a small evap leak that could be caused by several different reasons.

 

[PA Ram]

What code is showing up with the scanner? I can't imagine a warning light on without showing a specific code?
Keep in mind that the system is detecting a small evap leak in the fuel system. The gas cap comes on because that is a common issue (people forgetting to put it back on after fueling, etc...). However there is no specific sensor that knows if the actual gas cap is on or not, it only senses a small evap leak that could be caused by several different reasons.

This ^^^^^^

 

[Hemi395]

ESIM is the #1 thing to cause evap issues on these trucks. That and the purge solenoid.

Proper diag is key tho...

 

[stenerson]

This ^^^^^^

I had that tighten gas cap message stay on without a CEL light.

 

[CaptOchs]

Yeah. I bought a new aftermarket cap and smoothed the rusty area top of filler neck where it sits. The old gas cap was a little loose when tightening up. But the gas cap light issue didn't go away until I changed that ESIM. Personally I'd try replacing that before taking it to a stealership.

Thanks. Amazon just delivered the part. Will try and get it installed soon.

 

[CaptOchs]

What code is showing up with the scanner? I can't imagine a warning light on without showing a specific code?
Keep in mind that the system is detecting a small evap leak in the fuel system. The gas cap comes on because that is a common issue (people forgetting to put it back on after fueling, etc...). However there is no specific sensor that knows if the actual gas cap is on or not, it only senses a small evap leak that could be caused by several different reasons.

I did have the small evap leak. It's now a historical fault and CEL is off. I still have the pestering gas cap. We'll see what the esim does since it was cheap and common.

 

[stenerson]

Thanks. Amazon just delivered the part. Will try and get it installed soon.

I found this video helpful when installing mine.
Boosted Motor Sports RAM TRUCK GAS CAP LOOSE P0456 P0457 HOW TO REPAIR

 

[PA Ram]

I did have the small evap leak. It's now a historical fault and CEL is off. I still have the pestering gas cap. We'll see what the esim does since it was cheap and common.

My check gas cap light went off after changing the ESIM. I did replace my gas cap before that (aftermarket one). My original gas cap did fit loose and new one fits much better. Never had any issues after changing my ESIM.

 

[GTyankee]

OEM Gas Cap is the last thing to check, when you get the p0456 Code, even though it is the 1st thing Listed.
This is a Little Known, 100% FREE Check, when you get that Trouble Code.

Check the PURGE Valve first.

You can check it, when it is still on the Engine,
OR when it is removed.

The Purge Valve works on Air

Just watch the Videos

Quick Easy Test For Stuck Open Evap Purge Valve

In this video I show a quick and easy way to test to see if an evaporative emissions purge valve is stuck open due to an internal mechanical fault. (The evap...

www.youtube.com

(Ram 1500) Quick Diag of P0456 code (Evap small leak)

2015 Ram 1500 5.7L HemiShowing a quick method to verify a faulty Evap Purge Valve, by using a hand vacuum pump.Music created by "THELUFFLIFE"

www.youtube.com

bad ESIM

RAM TRUCK GAS CAP LOOSE HOW TO FIX ERROR P0456 or P0457 #Ramtrucks #ram1500 #ram2500

How to fix GAS CAP LOOSE Error P0456 and or P0457 on a RAM TRUCK and get rid of the check engine light issue on my 4th GEN RAM1500 pickup truck with the 5.7L...

www.youtube.com

RAM TRUCK GAS CAP LOOSE P0456 P0457 HOW TO REPAIR

We fix the RAM TRUCK GAS CAP LOOSE Error P0457 and show how to repair this check engine light and issue on this ram1500 pickup truck with the 5.7L HEMI engin...

www.youtube.com

 

[CaptOchs]

Thanks all for the ESIM recommendation. It's a $20 part on Amazon and EASY to replace. I pulled the old one off and it had a ton of green corrosion on one pin. Attached a picture and you can see there is a clean break in one of the two pins. It's a little hard to see. I had to bend the gas tank heat shield to see it.

The CEL came back so I cleared it after replacing the part. I started it up and still had the gas cap message. So I took it for a 10 minute ride. I did some light and heavy acceleration. I hit the expressway for a few miles. Just as I was about to get off the gas cap message went away. So crossing fingers that it will stay off.