My "check gas cap" saga - Fixed!

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

EdGs

Senior Member
Joined
Nov 29, 2020
Posts
2,478
Reaction score
3,556
Location
FL
Ram Year
2015
Engine
Hemi 5.7L
Wanted to start a new thread on this in case my situation is different than @fijicorey.

2015 Ram 1500 SLT QC 5.7L 8SPD 2WD

140K miles.

A few days ago, I got the 'check gas cap' message in my evic.

I was not able to get a new cap right away, but picked one up at the dealer yesterday ( the oe one was on backorder, they gave me one without the tether, no biggie, switched my tether to it, $35)

Message did not clear with the new cap, and the check engine light also came on. I stopped at a local O'reillys and borrowed their reader - 8 codes:

1. P0456 small evap leak
2, 3. P0457 gas cap loose
4. P0456
5. P0440 general evap failure
6. P0441 evap purge system performance
7. I missed that one I believe P0456 again
8. P0457

I did buy the Dorman 310-219 evap pump, but need to check the purge solenoid and hoses as well tonight.

I'm not worried about having purchased the cap and pump as I am at 140k miles.

Also, when I reset the dtc's, it said 2 are permanent, the P0456 and P0457 I believe.

Is there anything that jumps out at any of you?
 

e3mrk

Junior Member
Joined
Sep 5, 2021
Posts
18
Reaction score
25
Location
Ohio
Ram Year
2013
Engine
5.7 Hemi
I get the check gas cap on my 2013 Ram and it took a while but I found the problem The gasket in the cap gets distorted and then cant seal properly so I discovered by trial and error that if I spread a light film of grease on the O ring it solves the problem. I think the reason the gasket goes bad is it isn't solid O Ring and flattens out over time and greasing it makes it last a lot longer.
 
OP
OP
EdGs

EdGs

Senior Member
Joined
Nov 29, 2020
Posts
2,478
Reaction score
3,556
Location
FL
Ram Year
2015
Engine
Hemi 5.7L
New gas cap on mine, the old one didn't look in the greatest shape.
 
OP
OP
EdGs

EdGs

Senior Member
Joined
Nov 29, 2020
Posts
2,478
Reaction score
3,556
Location
FL
Ram Year
2015
Engine
Hemi 5.7L
I finally changed the Leak Detection Pump.

I was not able to reset the codes, and I still had the check gas cap message and the check engine light.

After a few cycles, the check gas cap went away, but the check engine light is still lit.

Do I have to physically reset the stored codes, or will the light go out on its own? I just didnt have access to a scan tool.
 
OP
OP
EdGs

EdGs

Senior Member
Joined
Nov 29, 2020
Posts
2,478
Reaction score
3,556
Location
FL
Ram Year
2015
Engine
Hemi 5.7L
I ended up going to an O'reilly's and having them read the codes, just showed the stored P0456 P0457.

He couldn't reset it, so he let me press the 'reset' button on the scan tool. So far, so good.
 

Wulf

Senior Member
Military
Joined
May 16, 2021
Posts
182
Reaction score
77
Location
United States
Ram Year
2021
Engine
5.7 Hemi
I do not know on these newer vehicles if there is a similar process, but on an older vehicle I had, you could check the codes by cycling the ignition key from off to on (without starting it), and back a certain number of times, and it would display the code(s) currently stored. And then, if I remember right, there was a similar method to clear them, just repeat that on/off thing a time more, or something.
 
OP
OP
EdGs

EdGs

Senior Member
Joined
Nov 29, 2020
Posts
2,478
Reaction score
3,556
Location
FL
Ram Year
2015
Engine
Hemi 5.7L
I do not know on these newer vehicles if there is a similar process, but on an older vehicle I had, you could check the codes by cycling the ignition key from off to on (without starting it), and back a certain number of times, and it would display the code(s) currently stored. And then, if I remember right, there was a similar method to clear them, just repeat that on/off thing a time more, or something.
I remember having to do stuff like that on older vehicles, not sure if something similar for newer ones, though.

It's been about 3 weeks, and no lights or codes, hooray!
 

firepuppet66

Junior Member
Joined
Nov 29, 2021
Posts
22
Reaction score
18
Location
Ottawa, Ontario Canada
Ram Year
2009
Engine
hemi 5.7
I had the same issue. After checking the forums and watching you tube vids (and after trading gas caps with a buddy) I determined the problem with my 2009 Laramie crew cab 5.7L was the evap pump. I bought one at the dealer. Crawled all over under the truck. Where is the darn thing? Vids I watched indicated that various years and models have it in different locations. Crawled under the back (no spare tire) and aha! There it is on top of the gas tank at the back. As per the vids it's easy to change (dirty greasy job working over the rear diff). Ran the truck, gas cap symbol went away but not check engine. Used Blue Driver code reader and cell phone. select clear all codes (must have engine off, key to "on"). It cleared.
 

El Guapo Phil

Senior Member
Joined
Jun 2, 2020
Posts
101
Reaction score
156
Location
Belize, Central America
Ram Year
2016
Engine
Hemi 5.7
I had a similar issue with the codes and light on the dash. I changed the gas gap. Light went out but returned 4 weeks later. I decided to change the PCV and the Purge Valve (less than $60 for both). Installed three months ago. No lights and no codes showing up.

It was just time to change those items. Glad I did.
 

Jack W

Member
Joined
Dec 30, 2021
Posts
39
Reaction score
13
Location
Texas
Ram Year
2005 2017
Engine
Hemi 5.7
Where is the purge valve located?
 

GTyankee

Senior Member
Supporting Member
Military
Joined
Nov 2, 2020
Posts
10,060
Reaction score
12,606
Location
El Cajon Calif. 92021
Ram Year
2016
Engine
3.0 ecodiesel
I believe the Purge Valve is always under the Hood

Older Rams have it under the Battery/Fuse Box
2005


late 2014, it is next to the throttle body, under the big air hose

 

Justin33

Senior Member
Joined
May 16, 2015
Posts
483
Reaction score
111
Ram Year
2015
Engine
Hemi 5.7
So I have the same year truck as you do. Gf had filled truck and awhile after got a gas cap code. She pushed more in after the click told her not to do that again. My main thing is I used Alfa and I don’t see the code populated, I do see a third break light which I need to take care of too. Anyone have any idea why the check engine light isn’t showing a code when I use alfa? I’m pretty sure I’m doing it right as I’ve named cbs he’s on the truck with the app and my tablet already.
 
OP
OP
EdGs

EdGs

Senior Member
Joined
Nov 29, 2020
Posts
2,478
Reaction score
3,556
Location
FL
Ram Year
2015
Engine
Hemi 5.7L
I think mine showed the gas cap symbol before the check engine light lit.

I had to look up what it was, had never seen a symbol like it before.

After I replaced the ESIM, it took a few drive cycles to clear the check engine light.

Now 35k miles since, no issues.
 

Justin33

Senior Member
Joined
May 16, 2015
Posts
483
Reaction score
111
Ram Year
2015
Engine
Hemi 5.7
Yeah I need to
I think mine showed the gas cap symbol before the check engine light lit.

I had to look up what it was, had never seen a symbol like it before.

After I replaced the ESIM, it took a few drive cycles to clear the check engine light.

Now 35k miles since, no issues.
Yeah I need to check the purge. The esim is the one above the tank right…luckily I have four inch super lift I think it wouldn’t be terrible. How did you know that was the issue. I checked cap and it looks good don’t think that’s it. I also can’t figure out why alfaodb won’t clear out the code and why it’s not even showing up.
 
OP
OP
EdGs

EdGs

Senior Member
Joined
Nov 29, 2020
Posts
2,478
Reaction score
3,556
Location
FL
Ram Year
2015
Engine
Hemi 5.7L
Yeah I need to

Yeah I need to check the purge. The esim is the one above the tank right…luckily I have four inch super lift I think it wouldn’t be terrible. How did you know that was the issue. I checked cap and it looks good don’t think that’s it. I also can’t figure out why alfaodb won’t clear out the code and why it’s not even showing up.
The ESIM wasn't super expensive, I just took a chance that was it. My truck had 140k miles at the time, so it was due for either, IMO.

I couldn't find or see any issues in the lines.

Wasn't bad to change, either.
 
Last edited:

Justin33

Senior Member
Joined
May 16, 2015
Posts
483
Reaction score
111
Ram Year
2015
Engine
Hemi 5.7
The ESIM wasn't super expensive, I just took a chance that was it. My truck had 140k miles at the time, so it was due for either, IMO.

I couldn't find or see any issues in the lines.

Wasn't bad to change, either.
Thinking it may be my issue as she shoved more gas into it after the click. So you didn’t check the purge under the engine cover first?
 
OP
OP
EdGs

EdGs

Senior Member
Joined
Nov 29, 2020
Posts
2,478
Reaction score
3,556
Location
FL
Ram Year
2015
Engine
Hemi 5.7L
Thinking it may be my issue as she shoved more gas into it after the click. So you didn’t check the purge under the engine cover first?
No

First I got a gas cap from the dealer, because mine didn't really look that good. It was something like $35.

The Dorman ESIM was only $25 or $30, so that wasn't a big hit either.

Even if I did buy the purge valve, I think it wouldn't be terribly expensive either.

I too, used to cram as much extra fuel in after the click, but now not much at all, maybe 25 or 50 cents, but that's it.
 

Justin33

Senior Member
Joined
May 16, 2015
Posts
483
Reaction score
111
Ram Year
2015
Engine
Hemi 5.7
No

First I got a gas cap from the dealer, because mine didn't really look that good. It was something like $35.

The Dorman ESIM was only $25 or $30, so that wasn't a big hit either.

Even if I did buy the purge valve, I think it wouldn't be terribly expensive either.

I too, used to cram as much extra fuel in after the click, but now not much at all, maybe 25 or 50 cents, but that's it.
My cap seal looks good. Had maybe a little oxidation on neck on the inside so I used aluminum foil and rubbed it down. I’m thinking it has to be the purge or what you replaced. I know each options isn’t expensive and a lot less than the 600 the dealer will probably be asking for. I just don’t think it’s the cap.
 
OP
OP
EdGs

EdGs

Senior Member
Joined
Nov 29, 2020
Posts
2,478
Reaction score
3,556
Location
FL
Ram Year
2015
Engine
Hemi 5.7L
I would say 99/100 times it's not the cap.

My cap did look terrible, the o-ring had some small cracking going on, don't know why, but wasn't the fix.
 
Last edited:
Top