Fault code for "small" leak in evap system.....

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.

Fnjoey

Senior Member
Joined
Aug 6, 2018
Posts
116
Reaction score
88
Location
New Jersey
Ram Year
2019
Engine
5.7 hemi
I have a 2014 1500 with about 48k on it and A couple of months ago, on a random hot ass day here in NJ, I left work, started my truck and *ding* look up to see my cel on.. ****.. grab my scanner (yes I keep one in my truck, who doesnt?) Scan, forgot the number but came up as small leak in evap system. Ok, gas cap... take off and put back on until click clicky.. clear code and off I go.. ran the full tank and it never came back on.. go get gas, ran through that whole tank and nothing. Cool. 3rd full, and a day or two after , light comes on again.. same code. Take the cap off and put it back on. Didn't have an issue after that.. well now it's happening more.. and its ******* me off.. aside from throwing money at it, what else should I be looking at besides a new gas cap (will be ordering one today) as to not waste money replacing everything until I find the issue at hand, if the new cap doesn't work.
 

Tach_tech

Senior Member
Joined
Jun 1, 2014
Posts
3,307
Reaction score
3,555
Ram Year
2017
Engine
5.7L HEMI
Literally any component in the evap system can cause a leak. Gas cap,lines,fuel tank, filler neck, evap canister,ESIM, purge solenoid etc.

The most common issues I see are no leaks at all and it’s the ESIM causing a false leak result, or the evap purge solenoid, but usually the ones that are mounted on the intake manifold. The purge solenoids that are near the battery almost never seem to leak. The gas cap is easy to change but in my experience it’s not often the issue.

The small leak test can also take a few weeks if not more to complete depending on conditions.

Really the only thing you can do with out an evap smoke machine is do a visual inspection of everything and make sure there’s nothing obviously wrong. You could disconnect the tank side of the purge solenoid and run the engine and make sure there’s no vacuum on that side, that would indicate a leak.
 
OP
OP
Fnjoey

Fnjoey

Senior Member
Joined
Aug 6, 2018
Posts
116
Reaction score
88
Location
New Jersey
Ram Year
2019
Engine
5.7 hemi
Great.... ibhate chasing down stuff I can't find with out some other tool...
 

srv1

Senior Member
Joined
Nov 7, 2019
Posts
327
Reaction score
222
Location
blasdell n.y
Ram Year
2004
Engine
345 c.i. HEMI MAGNUM
You can chase it and throw parts at it or you can do a smoke test.There are many diy smoke machine videos on line.I made one with a pickle jar,and an aquarium pump.It works great!The evap test must fail twice before you will get a cel and there are alot of parameters to be met to get the evap monitors to run,so i've heard.It is also a 2 part test with the "small leak test" being made after the truck is parked.My evap system is slightly different than yours.I have an nvld and I believe you have the esim.These are both common problems as they are the "back door" of the system that closes for the evap test.The "front door" will be the purge valve,another common problem.This can be tested with a hand vac. pump.Some other common places for leaks is around the filler neck,the top of the tank where the fuel pump is and all of the hoses around the charcoal canister.Good luck.Also,make sure to use a mopar cap or whatever else you may replace.The hemi is finnicky *****.
 
OP
OP
Fnjoey

Fnjoey

Senior Member
Joined
Aug 6, 2018
Posts
116
Reaction score
88
Location
New Jersey
Ram Year
2019
Engine
5.7 hemi
Just Google some stuff. Hand pump on the purge valve seems to be common. I'll give that a try first and see if the pv is what is causing the issue. Its cheap enough that if I'm wrong it's ok.
 

vernitron

Junior Member
Joined
Mar 30, 2021
Posts
19
Reaction score
6
Location
Arizona
Ram Year
2017
Engine
5.7L
I had the same issue on my JK Wrangler. Replaced the gas cap, checked hoses etc. Didn't do a smoke test. I don't know if the RAMs do this differently, but on my JK there was a vacuum operated switch that I think was connected to the charcoal canister in the rear. When the fuel system would cool it created a vacuum and closed that switch. I had read on Jeep forums this was a potential culprit due to dust getting in there. I replaced that vacuum switch and voila, never got a code after that. It was fairly inexpensive and easy to replace. Apparently on these jeeps (2008), Chrysler did this differently than everyone else in the industry. If it didn't fix it I was going to wire in a manual switch to fool it.
 

Hanover Fiste

Senior Member
Military
Joined
Apr 29, 2020
Posts
379
Reaction score
1,009
Location
NW Florida
Ram Year
2005 SLT, 2018 Sport
Engine
5.7L Hemi
The code is P0456. I've had that code appear in my 2005 for a couple years now. I've replaced the gas cap, charcoal canister, purge solenoid, plus a couple other parts, and the code still appears. When I reset it, sometimes it reappears the next day; or, it could take a couple months. The truck still runs just fine, so I just reset it and go on my merry way.
 
OP
OP
Fnjoey

Fnjoey

Senior Member
Joined
Aug 6, 2018
Posts
116
Reaction score
88
Location
New Jersey
Ram Year
2019
Engine
5.7 hemi
The code is P0456. I've had that code appear in my 2005 for a couple years now. I've replaced the gas cap, charcoal canister, purge solenoid, plus a couple other parts, and the code still appears. When I reset it, sometimes it reappears the next day; or, it could take a couple months. The truck still runs just fine, so I just reset it and go on my merry way.

That's the code. I'm just tired of having to take out my scanner to reset the cel. I bought a new purge valve as that seems to be the issue, just have to find time to put it in.
 

PolarisCobra

Senior Member
Joined
Jul 16, 2018
Posts
457
Reaction score
643
Location
Mendon, MA
Ram Year
2017
Engine
5.7 HEMI
On my 2017, I fixed it by replacing the purge valve. Very easy, not expensive. I found a you tube video of an older guy who had a very good explanation of how that system works, and how to test things without a smoke tester. Basically, take the purge valve off, blow in it. Should be closed tight.

Sure enough, i could blow through mine a little. New one was tight. Cleared the code, no more message.

When it happened, truck was under warranty. Took it to dealer, they did a smoke test. Told me it was gas cap, not covered under warranty. Code came back in a month or so. I did some searching on line, found the video, fixed it myself. No point taking it back to the dealer if they can't figure it out with their high tech tool. Cost me about $200 for a gas cap that I didn't even need...
 
OP
OP
Fnjoey

Fnjoey

Senior Member
Joined
Aug 6, 2018
Posts
116
Reaction score
88
Location
New Jersey
Ram Year
2019
Engine
5.7 hemi
On my 2017, I fixed it by replacing the purge valve. Very easy, not expensive. I found a you tube video of an older guy who had a very good explanation of how that system works, and how to test things without a smoke tester. Basically, take the purge valve off, blow in it. Should be closed tight.

Sure enough, i could blow through mine a little. New one was tight. Cleared the code, no more message.

When it happened, truck was under warranty. Took it to dealer, they did a smoke test. Told me it was gas cap, not covered under warranty. Code came back in a month or so. I did some searching on line, found the video, fixed it myself. No point taking it back to the dealer if they can't figure it out with their high tech tool. Cost me about $200 for a gas cap that I didn't even need...


Yeah, I Googled how to diagnose my issue and found a you tube of a guy checking the purge valve with a hand vac pump. I looked up the part and it was $17, so I figured I have nothing to lose I'd it isn't that part. I hope to change it out this weekend so I'll check it then. Considering it's plastic, and it right on the engine, I wouldnimagine over time the plastic warps and causes the issues..
 
OP
OP
Fnjoey

Fnjoey

Senior Member
Joined
Aug 6, 2018
Posts
116
Reaction score
88
Location
New Jersey
Ram Year
2019
Engine
5.7 hemi
Just a quick update, I replaced the purge valve and it seems to have fixed the issue.. haven't had the cel come on yet and it's been over a week. When I pulled the old one I was able to suck air through it ever so slightly.. compared to the new one where nothing came through. So I'm assuming that did it.
 

daveray9

Senior Member
Joined
Oct 22, 2015
Posts
1,698
Reaction score
585
Ram Year
2020
Engine
Hemi 5.7
Anyone know how to replace the purge valve on a 2012? I saw all the videos on the 13s and up but cant find one for the 2012... its not in the same place as the 13s and up.
 

Glenn Chaisson

Junior Member
Joined
Nov 7, 2021
Posts
4
Reaction score
0
Location
Santa Fe Texas
Ram Year
2004
Engine
5.7
I have a 2014 1500 with about 48k on it and A couple of months ago, on a random hot ass day here in NJ, I left work, started my truck and *ding* look up to see my cel on.. ****.. grab my scanner (yes I keep one in my truck, who doesnt?) Scan, forgot the number but came up as small leak in evap system. Ok, gas cap... take off and put back on until click clicky.. clear code and off I go.. ran the full tank and it never came back on.. go get gas, ran through that whole tank and nothing. Cool. 3rd full, and a day or two after , light comes on again.. same code. Take the cap off and put it back on. Didn't have an issue after that.. well now it's happening more.. and its ******* me off.. aside from throwing money at it, what else should I be looking at besides a new gas cap (will be ordering one today) as to not waste money replacing everything until I find the issue at hand, if the new cap doesn't work.
The snap on cap on the diaphragm of the Leak Detection Module Pump on mine was not snapped on tight to make a seal. It is the flat top on the attached picture. I can’t believe I finally found my issue! It to sooooooo long to figure this one out. I hope this is your issue also
 

Attachments

  • FCDEF264-E2DC-4A1D-9D6E-1021B7AB7040.png
    FCDEF264-E2DC-4A1D-9D6E-1021B7AB7040.png
    471.1 KB · Views: 9
Top