How I Fixed My Code P0456

If it's about Power Wagons, all generations, this is where it'll go. This is the original PWR Forum Power Wagon Technical Discussion Section. And this includes everything that doesn’t fit in any one of the other categories related to the truck goes here!
Post Reply
User avatar
Retired BLM Rig
500_Posts
500_Posts
Posts: 799
Joined: Sun Jan 31, 2016 6:51 pm
Model Year: 2008
Location: San Clemente, Ca.

How I Fixed My Code P0456

Post by Retired BLM Rig » Sat Dec 31, 2016 2:30 am

Re: Check engine light on due to code P0456 (small evaporative system leak detected). All of this information applies to a 2008 PW, but the theory should apply to any vehicle (sometimes they change the name of system components from year to year).

It's been a couple months since my check engine light first came on because of this code. When I read what it was on my scanner, I cleared the code and checked my gas cap for tightness and forgot about it since it was nothing serious. But then it started repeating the same code every week or two, so I figured I better get to the bottom of it.

The most common failure is a bad rubber seal on the gas cap, even though I couldn't see any cracks or deformities, I decided to replace it since it was the original eight year old cap. I got an O.E. Mopar replacement, cleared the code again and waited to see if it would come back on. Sure enough, after a few more trips to work, the CEL popped back on with the same code. :evil:

Next on my diagnostic list was to carefully check all of the rubber and plastic lines in the evaporative system for cracks, splits or loose connections. I started at the evap/charcoal canisters mounted just in front of my fuel tank and followed each line to and from the canisters throughout the entire system. The hardest ones to check are on top of the fuel tank, but a good flashlight and mirror can help with those. I didn't find any problems with the lines, so now it was time to focus on components.

The first and most obvious component is the canister. It's pretty well protected between the frame rails, but you never know when a stray stone or piece of road debris may get kicked up there and damage something. Mine looked good with no signs of splits or cracks.

Every evap system has a vent/inlet somewhere, mine is above the transmission bell housing.
001.jpg
If pressure needs to be vented or air needs to be drawn in, this is where it happens.
The cap is just an open restrictor to stop debris or bugs, like mud dobbers, from building a nest and plugging the vent line.

The next component inline is the filter, this is to stop any dust from entering the evaporative system. It's a mini air filter inside a plastic housing.
002.jpg
My filter sits on top of the evap/charcoal canister assembly.
The next component is called the "Evaporative System Integrity Monitor" (ESIM for short). It locks on to the canister. This is a double weighted check valve that allows pressure venting or vacuum relief at predetermined pressures based on the weight of the check valves.
003.jpg
The ESIM is the bad boy that will turn on your check engine light if it sees that pressure/vacuum isn't being maintained in the system. It's a leak detector, that's what the two wires are for.
To remove the ESIM, lift up the locking tab and rotate it 45º clockwise.
004.jpg
There's an o-ring under the ESIM, make sure it doesn't get lost and check it's condition.
007.jpg
The ESIM is glued together and is supposed to be non serviceable :thppt: . Looking inside the ESIM you can see that a layer of superfine dust made it past the filter media and took up residence on the check valve causing it not to seal.
005.jpg
006.jpg
My solution was to spray aerosol brake cleaner into the ESIM, shake it around and then quickly blow it out with compressed air. I did this two or three times until it looked clean. Make sure not to let the chemical sit for too long as it will ruin the rubber check valve (spray it in, shake and blow it out). The ESIM is available to purchase as an individual part for $30-40, but why buy it if you can clean it.

The next thing I did was blow out the vent filter and lines (a rather impressive cloud of dust). In fact it wouldn't be a bad idea to make this an annual maintenance item if your truck spends a lot of time off road or in dusty conditions.
008.jpg
Blowing out the vent line.
It's been a couple weeks since I did all this work and so far no check engine light and no pending codes. If this hadn't fixed it, other components to check would include the purge solenoid valve (under the hood), fuel fill neck and hoses, fuel pump/sending unit & o-ring and finally the fuel tank.

After seven years of government work in the desert, the dust finally took its toll. Luckily I was able to find it and fix it with the investment of a little time and effort. I hope this will help someone else that may be experiencing the same problem and help save some money and a trip to the dealer/shop.

Happy New Year!!! :patriot:

waldo
250_Posts
250_Posts
Posts: 374
Joined: Sat Dec 26, 2015 7:46 am
Model Year: 2007

Re: How I Fixed My Code P0456

Post by waldo » Sat Dec 31, 2016 7:53 am

Good info and post. Thanks.
2007 and 2019 Power Wagons

User avatar
cruz
500_Posts
500_Posts
Posts: 996
Joined: Sat May 26, 2012 11:36 am
Location: Santa Cruz, CA

Re: How I Fixed My Code P0456

Post by cruz » Sat Dec 31, 2016 12:00 pm

waldo wrote:Good info and post. Thanks.
X2
While we're on the subject, here is another P0456 code problem that I had a while back ...
http://forum.powerwagonregistry.org/vie ... 456#p53100
2005 Power Wagon

User avatar
DamageWagon
Vendor
Vendor
Posts: 2150
Joined: Tue Oct 11, 2016 1:21 am
Model Year: 2011
Location: Portland, OR
Contact:

Re: How I Fixed My Code P0456

Post by DamageWagon » Sat Dec 31, 2016 12:05 pm

Thanks man, I'm going to have to try this on my truck. I'm having the same issues and its spent a lot of time in dust and mud. Great write up, hopefully to something easy on mine as well!


Sent from my iPhone using Tapatalk

flattire
250_Posts
250_Posts
Posts: 326
Joined: Fri Jun 08, 2012 1:22 pm

Re: How I Fixed My Code P0456

Post by flattire » Sat Dec 31, 2016 12:52 pm

WOW!

This is the best "how to fix" write up of anything I have seen . :rockon:

In focus photos with proper lighting.
Arrows and comments for details.
How to do it and materials to use procedure.

In school terms a "100%" grade. :patriot:

Future articles suggestions: :secret:

Replace broken exhaust studs.
Tie rod ends and ball joint troubleshoot (and replace).
How to grease driveshaft.
Tranny and diff service.

And if that isn't enough:

How to fix "serv4wd" light for under $100.00. :rofl: ( This might be a challenge.)

:cheers:

TwinStick
2000_Posts
2000_Posts
Posts: 4162
Joined: Mon May 28, 2012 7:58 pm
Model Year: 2008

Re: How I Fixed My Code P0456

Post by TwinStick » Sat Dec 31, 2016 3:07 pm

AWESOME write up,pics & commentary ! :notworthy:

And really, what is the actual purpose of all that plastic crap ? :cash: :cash: :cash: :cash: :cash: :cash: :cash: :cash: :cash: :cash: :cash: :cash: :cash: :cash:
Traded to 2019 ZR2, Red.

4Runner was a GREAT vehicle but could not even tow our 6x10 enclosed utility trailer comfortably, even when it was empty-ish.

It was time. Truck was still leaking BADLY every time it rained or snowed & melted. It was leaking at every single gasket (rear window, front window, all 4 doors). You could sit inside & watch it run down the inside of windshield, rear window & drip off the upper side door beams. It was molding on the inside & starting to stink. Needed new steering gearbox, shocks, new upgraded T-style steering, tires, brake lines, d/s manifold bolts that are barely recognizable due to rust-removed & replaced. Everyone around here would not even touch em once they looked at them.

So, say what you will. PW turned into a money pit. Was no longer a joy to drive. Hoping that this downsized 4x4 with lockers will fill the bill & have minimal problems, but..... As long as manufacturers keep making engineers design things that fail soon after warranty is up, we are going nowhere fast. Regardless of what you buy. :rockon:

flattire
250_Posts
250_Posts
Posts: 326
Joined: Fri Jun 08, 2012 1:22 pm

Re: How I Fixed My Code P0456

Post by flattire » Sat Dec 31, 2016 7:25 pm

A simple concept gone crazy by regulation.

What started as a charcoal filter to absorb gas fumes has become this system. I had no idea all this stuff was even there.

Plastic = cheap to make ....sure to fail....expensive to replace. :doh:

User avatar
BigRed2007
250_Posts
250_Posts
Posts: 298
Joined: Sun Jul 15, 2012 5:08 pm
Model Year: 2007
Location: Central Texas

Re: How I Fixed My Code P0456

Post by BigRed2007 » Sun Jan 01, 2017 9:12 am

Great write up. Hopefully I'll be able to find it when I get a chance to try to fix that code. I've had it for at least the last five years....

Sent from my XT1254 using Tapatalk
Flame Red 07 PW - BIG RED
White Knuckle Offroad Rock Sliders, Volant Intake, LightForce 210 HID x2, HiLift Mounted on Tool Box, Locker Bypass, OBA - EXTREMAIRE Magnum, High Idle, 315/70/17 MTR/Ks, ARB Front Bumper, Synthetic Winch Rope, 3000 Watt Inverter, Carli Performance 2.0 Front end and rear shocks, DT PROFAB Steering brace and Steering Stabilizer,Carli Front Diff Gaurd, 12v Fridge Freezer, Dual Optima Yellow Tops, AirFlow Snorkle, Magnaflow Muffler and Y-Pipe, 2x50W Solar Panels, DOR Control Arms.

KE0BZG
WQUY939

RustyPW
2000_Posts
2000_Posts
Posts: 4603
Joined: Thu May 24, 2012 4:23 pm
Model Year: 2008
Location: Brownsville Pa.

Re: How I Fixed My Code P0456

Post by RustyPW » Sun Jan 01, 2017 4:13 pm

Excellent write up! :rockon:
PWOC #53
2008 POWER WAGON RC

My build thread. viewtopic.php?f=13&t=2826 :cash: :cash:

Moab '10, '12, '14.
Rausch Creek - Summer '10, Spring-Fall '11, Spring '12, Summer '13, Summer '14, Summer '15, Summer '16, Summer '17, Summer '18, Summer '19 AOAA,

Russ
NRA - Benefactor, Golden Eagle. :lockedandloaded:


User avatar
adeluca73
2000_Posts
2000_Posts
Posts: 2124
Joined: Mon May 19, 2014 11:56 pm
Model Year: 2014
Location: The Pentagon, VA

Re: How I Fixed My Code P0456

Post by adeluca73 » Mon Jan 02, 2017 9:38 am

Very thorough. What a giant PIA for a system that's much like a vestigial organ....useless
2014 Ram PW SLT: 1st year of the Best Gen
<Build Thread>

TwinStick
2000_Posts
2000_Posts
Posts: 4162
Joined: Mon May 28, 2012 7:58 pm
Model Year: 2008

Re: How I Fixed My Code P0456

Post by TwinStick » Mon Jan 02, 2017 9:26 pm

Retired BLM Rig wrote:Thanks for the feedback guys! :patriot:
1gy3xh.jpg

:lol: Thats the OLD MIMITW. You got to update ! :lol:

https://www.youtube.com/watch?v=8KqjvM7r2xY
Traded to 2019 ZR2, Red.

4Runner was a GREAT vehicle but could not even tow our 6x10 enclosed utility trailer comfortably, even when it was empty-ish.

It was time. Truck was still leaking BADLY every time it rained or snowed & melted. It was leaking at every single gasket (rear window, front window, all 4 doors). You could sit inside & watch it run down the inside of windshield, rear window & drip off the upper side door beams. It was molding on the inside & starting to stink. Needed new steering gearbox, shocks, new upgraded T-style steering, tires, brake lines, d/s manifold bolts that are barely recognizable due to rust-removed & replaced. Everyone around here would not even touch em once they looked at them.

So, say what you will. PW turned into a money pit. Was no longer a joy to drive. Hoping that this downsized 4x4 with lockers will fill the bill & have minimal problems, but..... As long as manufacturers keep making engineers design things that fail soon after warranty is up, we are going nowhere fast. Regardless of what you buy. :rockon:

User avatar
DamageWagon
Vendor
Vendor
Posts: 2150
Joined: Tue Oct 11, 2016 1:21 am
Model Year: 2011
Location: Portland, OR
Contact:

Re: How I Fixed My Code P0456

Post by DamageWagon » Tue Jan 10, 2017 2:04 am

So I followed your information there over the weekend and cleaned out my ESIM/NVLD. I took some pictures so people could see a little more. Brake cleaner and air dos perfect, it was obvious how much better it moves now. There is still dust inside it somehow that I can't get out. Oh well. You were right about how much dirt gets in that filter! I swiped my finger inside the ESIM to show the fine layer of dust that accumulates. ImageImageImageImage


Sent from my iPhone using Tapatalk

User avatar
DamageWagon
Vendor
Vendor
Posts: 2150
Joined: Tue Oct 11, 2016 1:21 am
Model Year: 2011
Location: Portland, OR
Contact:

Re: How I Fixed My Code P0456

Post by DamageWagon » Tue Jan 10, 2017 2:18 am

So I followed your information there over the weekend and cleaned out my ESIM/NVLD. I took some pictures so people could see a little more. Brake cleaner and air dos perfect, it was obvious how much better it moves now. There is still dust inside it somehow that I can't get out. Oh well. You were right about how much dirt gets in that filter! I swiped my finger inside the ESIM to show the fine layer of dust that accumulates. ImageImageImageImage


Sent from my iPhone using Tapatalk

User avatar
Retired BLM Rig
500_Posts
500_Posts
Posts: 799
Joined: Sun Jan 31, 2016 6:51 pm
Model Year: 2008
Location: San Clemente, Ca.

Re: How I Fixed My Code P0456

Post by Retired BLM Rig » Tue Jan 10, 2017 3:09 am

I know you had more than one code, but I hope that's all it was for you too. Time will tell.
Last edited by Retired BLM Rig on Tue Jan 10, 2017 9:26 am, edited 1 time in total.

User avatar
stamm20
50_Posts
50_Posts
Posts: 211
Joined: Fri May 25, 2012 1:51 pm
Model Year: 2007
Location: Greenville, NC

Re: How I Fixed My Code P0456

Post by stamm20 » Tue Jan 10, 2017 8:59 am

Great write up thanks man!!! I have a few EVAP codes in right now

Sent from my XT1254 using Tapatalk
07 Brilliant Black Power Wagon
Current Mods: 35x12.50x17 Kelly Fierce Attitude M/T, DiabloSport Predator tuner, 3in Super 40 with 3in dump, TPS bypass, Pioneer touch screen Nav System with ipod hookup, Carli front diff gaurd, Fox adjustable steering stabilizer, Mopar steering box upgrade weathertec floor mats, Fox 2.0 performance shocks, hardwired lockers, evo swaybar disconnect



Yea Though I wheel through the valley of the shadow of death,
I will fear no evil: For thou lockers are with me;
Thy lift and thy tires, they comfort me.
Thou preparest a spotter before me in the presence of mine obstacles

socalluke
Posts: 18
Joined: Mon Nov 24, 2014 8:43 pm
Model Year: 2012

Re: How I Fixed My Code P0456

Post by socalluke » Wed Aug 07, 2019 8:34 pm

No codes, but now, even the slow flowing gas station pumps are shutting off every 30 seconds, as I try to fill the gas tank.

-> Any tips for how to remove the filter, so I can blow air out the vent tube?

User avatar
Retired BLM Rig
500_Posts
500_Posts
Posts: 799
Joined: Sun Jan 31, 2016 6:51 pm
Model Year: 2008
Location: San Clemente, Ca.

Re: How I Fixed My Code P0456

Post by Retired BLM Rig » Thu Aug 08, 2019 9:22 am

socalluke wrote:
Wed Aug 07, 2019 8:34 pm
No codes, but now, even the slow flowing gas station pumps are shutting off every 30 seconds, as I try to fill the gas tank.

-> Any tips for how to remove the filter, so I can blow air out the vent tube?
It's just held on by one or two 10mm hex fasteners, very simple to remove and blow out. Be prepared for a large dust cloud.

Post Reply