P0456 Code

[JerryETX]

So I’ve been dealing with this code for many months now on my 2016 6.4 Hemi (60ish k miles). First time check engine light came on I went to Auto Zone and checked the code- P0456. They said it was likely the ESIM so I bought a new module from them (their house part) and installed it. Waited a few days and it worked. Check engine light gone. About a month later it happened again. Same code same part (warranty exchange) same results. About a month or two later happened again this time I went with a different hopefully better part. Same results. A couple of weeks ago happened again. This time I went with OEM Mopar ESIM purchased from the dealer. It’s been over a week and check engine light has not gone away.

Each time I have replaced the ESIM the check engine light has cleared (after 2 days of driving) for about a month or two then came back on except for this last time. This time check engine light is still on after 9 days.

There’s not a mechanic shop around me that I trust to try and fix this issue and the dealer has a 3 week waiting list just to get the truck in. Any ideas on what could be the issue?

 

[JohnCA]

I have had P0456 twice once for gas cap and once for the purge valve

 

[JerryETX]

I have had P0456 twice once for gas cap and once for the purge valve

Each time when you replaced these parts did you go with OEM or aftermarket parts?

 

[JW2 Innovations]

Anything to do with an error on an evaporator system, I have always struggled with it. Gas cap, purge valve, canister, canister filter......enough to drive you crazy!

I would check it all visually, and if you can't tell start with gas cap and purge valve. Cheapest parts go first if not obvious for me.

Weirdest one I ever had was the return line coming from the purge valve had rubbed another hose/something near the engine and the way they sat next to one another and their position back near the firewall it wasn't easy to see. But a hole had been rubbed into that line. I found a fuel hose of the closest I.D. and cut a small piece with some hose clamps and cut the purge return line using the small piece of rubber fuel line in it's place to seal it all up. Worked like a champ and cost me Zero.

So frustrating.

 

[JW2 Innovations]

Also note that the reason you're probably getting a delay between dash lights is that testing of that system doesn't usually happen until the car has warmed up and met some other running requirements. Dig around for what is the pre-req list before it will fire off a test. I think the last one I dealt with your fuel level had to be in a certain range as well if I remember right, temp, running over a certain rpms for so many minutes, etc. Anyways, when you reset the code it may be a bit before it fires off another test and if you haven't fixed the issue you'll just get another error code, but won't know it until the conditions to do a test are met again.

My daughters Jeep had a "small leak" once and not sure what criteria sets that code, but you would catch a whiff of gas smell when it was kicking off a test. That one ended up being the purge valve being swapped along with one piece of tubing connected to it just cause it looked degraded like it had been struck or something.

Hope you find it soon.

 

[chri5k]

It seems the ESIM is not the issue. You have a small leak in the evap system. The surest way to find the leak is with a "smoke machine". They are available on Amazon for $90 to $150. Many folks spend more than that amount on the "parts cannon" approach and still don't solve the issue. One other possibility is the ESIM is installed upside down. The ESIM uses gravity acting on a small weight as part of the system to detect a leak.

From the Standard Brand website:
Left image is correct. Right image is incorrect.



P0456 - EVAP Purge System Small Leak: When the ignition is turned OFF and the EVAP system is sealed, a change in the fuel tank vapor temperature/pressure occurs. If the ESIM switch does not close within a calibrated time, the PCM calculates a small leak of 0.02".

 

[carlucci89]

I had that code for a while too. It ended up being a hole in one of the tank lines. The dealer found it, it was not an expensive fix and has not returned.

 

[JerryETX]

It seems the ESIM is not the issue. You have a small leak in the evap system. The surest way to find the leak is with a "smoke machine". They are available on Amazon for $90 to $150. Many folks spend more than that amount on the "parts cannon" approach and still don't solve the issue. One other possibility is the ESIM is installed upside down. The ESIM uses gravity acting on a small weight as part of the system to detect a leak.

From the Standard Brand website:
Left image is correct. Right image is incorrect.

View attachment 517687

P0456 - EVAP Purge System Small Leak: When the ignition is turned OFF and the EVAP system is sealed, a change in the fuel tank vapor temperature/pressure occurs. If the ESIM switch does not close within a calibrated time, the PCM calculates a small leak of 0.02".

Interesting! I’m not near my truck but I may have installed it incorrectly looking at those images. I’ll check that out tomorrow.

 

[GTyankee]

Check your Purge Valve, it is near the throttle body & water pump

Real easy to access, pull it off & use your mouth to try to blow through it.
If you can blow through it, replace it

where it is located

2013-2016 Ram 5.7 Hemi evap purge solenoid replacement

Please use the following link when ever using Amazon.com. Any purchases you make on Amazon will help support this channel.http://amzn.to/2mALgqSFeel the need...

www.youtube.com

testing the purge valve
poor guy is slightly confused

(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

 

[JerryETX]

Ended up being the purge valve. Took me a bit to get it fixed been battling tendinitis elbow but was finally able to replace the purge valve last Saturday and check engine light went off this morning. Hopefully this is the last of these issues for a while.

Thanks for the advice guys.

 

[62Blazer]

Hopefully you got it fixed. The P0456 code is for a small evaporative leak of the fuel system and can be caused by numerous different things.
I would never, ever randomly throw parts at a vehicle based on what some person at Autozone stated. No offense to anybody that works there, but from my experience most of them have very little mechanical knowledge. On top of that somebody simply reading a code and telling you start throwing parts at it should not be listened to either. I almost always look up the actual part number I need and order based on that, versus jumping through the hoops to tell them what color the car is when ordering an oil filter.
I would also hope people might consider looking at something else if the issue was not fixed after replacing the same part multiple times. Sure, you might get a bad part one time and need to replace it (just because it's new doesn't mean it's good) but getting 2 bad parts in a row is not that common.
In regards to when the code comes on, it's pretty common to have long delays in re-activation of this code after being cleared. There is a whole series of "tests", or drive cycles, that need completed prior to a light engaging. And for many codes it would have to fail multiple tests before the ECM finally triggers a check engine light.

 

[briantmustang]

I have a 2018 dodge 2500 6.4 with a p0456 light and I smoked tested it and replaced the gas cap and the esim and I still get the p0456 and the gas cap light coming on. what else can it be?

 

[Rayzaa]

Hopefully you got it fixed. The P0456 code is for a small evaporative leak of the fuel system and can be caused by numerous different things.
I would never, ever randomly throw parts at a vehicle based on what some person at Autozone stated. No offense to anybody that works there, but from my experience most of them have very little mechanical knowledge. On top of that somebody simply reading a code and telling you start throwing parts at it should not be listened to either. I almost always look up the actual part number I need and order based on that, versus jumping through the hoops to tell them what color the car is when ordering an oil filter.
I would also hope people might consider looking at something else if the issue was not fixed after replacing the same part multiple times. Sure, you might get a bad part one time and need to replace it (just because it's new doesn't mean it's good) but getting 2 bad parts in a row is not that common.
In regards to when the code comes on, it's pretty common to have long delays in re-activation of this code after being cleared. There is a whole series of "tests", or drive cycles, that need completed prior to a light engaging. And for many codes it would have to fail multiple tests before the ECM finally triggers a check engine light.

True, i didnt consult them. I had that code as well and just started from the beginning and the cheapest part.
Gas cap from Amazon didn't fix it, purge valve from O'Reillys didn't fix it. The esim from same auto parts store fixed it.
Total cost about $85

 

[EastWestHemi]

Father in laws truck has this code still to this day. Smoked at a semi trust worthy dealer and found that something is cracked or broken on top of the gas tank where lines and stuff connect. Supposedly needs a new gas tank because nothing is serviceable. What a PITA. I shared a post awhile back on it. He doesn’t have $1500 sitting around throw a new gas tank under it, bad design IMO, truck is a 2016 with 80k miles. I hope it doesn’t happen to mine.

 

[JerryETX]

I have a 2018 dodge 2500 6.4 with a p0456 light and I smoked tested it and replaced the gas cap and the esim and I still get the p0456 and the gas cap light coming on. what else can it be?

So I went through several ESIM’s before buying a Mopar part and that makes a difference. This last time for me it was the purge valve. I ordered one online and it took me about 10 minutes to replace it and that’s only because I don’t have good eyes and was being careful. It’s more like a 5 minute job for most.

 

[Rayzaa]

Doesn't matter if it's a Mopar part or not. You have to replace the problem part which was the purge valve. Mine was the esim but I did the gas cap & purge valve first doing process of elimination.

 

[JerryETX]

Doesn't matter if it's a Mopar part or not.

Not true. I replaced the ESIM 3 times with Auto Zone parts and all 3 times were temporary fixes that didn’t work. I installed a Mopar ESIM and light went off and no issues until the purge valve went bad. I talked to a Jeep mechanic as well as the dealer and both said at least for the ESIM OEM matters

 

[Rayzaa]

Not true. I replaced the ESIM 3 times with Auto Zone parts and all 3 times were temporary fixes that didn’t work. I installed a Mopar ESIM and light went off and no issues until the purge valve went bad. I talked to a Jeep mechanic as well as the dealer and both said at least for the ESIM OEM matters

That's because according to you, the problem ended up being the purge valve and wasn't the main problem. It was likely on its way out as well.
Me I started w/ a gas cap and then purge valve which didn't fix it. Mine ended up being the esim, didn't use Mopar part.

Later on I needed a new oil pressure sensor and didn't use a Mopar part and it's fixed.

 

[JerryETX]

That's because according to you, the problem ended up being the purge valve. You could of put a Mopar esim in it and it wouldn't have fixed it.

I didn't use any Mopar parts and mine was fixed when I put in a new part that was the problem.

Later on I needed a new oil pressure sensor and didn't use a Mopar part and it's fixed.

To clarify it was between a week and two weeks from when I installed the Mopar ESIM and the check engine light went off to when the light came on again and I replaced the purge valve. I’m glad the aftermarket parts are working for you. I should’ve said not always true. In my case the Mopar ESIM clearly solved at least a 6 month long issue of going through aftermarket ESIM’s.

FYI- your aftermarket parts aren’t going to last as long as OEM parts, generally. Age also comes with learning and knowledge and I have learned that buying aftermarket parts is stepping over a dollar to save a dime. That’s of course my opinion.

 

[Rayzaa]

To clarify it was between a week and two weeks from when I installed the Mopar ESIM and the check engine light went off to when the light came on again and I replaced the purge valve. I’m glad the aftermarket parts are working for you. I should’ve said not always true. In my case the Mopar ESIM clearly solved at least a 6 month long issue of going through aftermarket ESIM’s.

FYI- your aftermarket parts aren’t going to last as long as OEM parts, generally. Age also comes with learning and knowledge and I have learned that buying aftermarket parts is stepping over a dollar to save a dime. That’s of course my opinion.

We'll see. It's been 2 years. Imo they are the same, they just slap another name on it. Has the same part number.

I mean you have to figure, it's Mopar parts that are failing and are common issues.