Hi Everyone -
This is my first post here so bear with me...I have been doing quite a bit of digging on the popular P0457 code.

I have a 2009 Chrysler Aspen (not a Flex-Fuel). The GAS Cap warning light in the odometer area came on about 2 months ago. Right around the same time I started getting a Cylinder 6 mis-fire. A new gas cap was purchased (not an OEM one) and the problem remained.

After finding out the engine needed to be replaced (thank goodness for a warranty), I am still left with this code that says the Gas Cap is missing or loose. I have since purchased an OEM gas cap from the Chrysler Dealership and that did not take care of the issue.

I just had a smoke test done on the vehicle because at one point I had the P0456 code as well indicating a small leak, but that was cleared and never came back. The smoke test came back with no leaks.

I have seem some posts about an ESIM sensor the the tech that just did the smoke test said after he cleared the codes the GAS CAP warning light came back on in like 3 seconds. This is very quick and the computer would not have had time to scan the vehicle to kick back that warning so he is thinking there might be a faulty wire somewhere.

Is there a gas cap sensor that might need to be replaced? What is this ESIM sensor and could this be the issue? I think the problem has narrowed itself to a faulty sensor or wiring issue as I do not actually have a leak or faulty gas cap.

Thank you so much for your help in advance!

 

I recently replaced this myself due to the same codes you are getting. Replacing the gas cap didn't fix it for me either.

The ESIM sensor (also called the EVAP Leak Detect Switch) is basically a valve which attaches to the charcoal canister. The charcoal canister is mounted under the truck just in front of the gas tank. It sits against the drivers side frame rail. The ESIM is easy to replace. Has one rubber hose which easily pulls off and one electrical plug. The hardest part is getting the mounting tab on the old ESIM to release so you can twist it off (counter clock wise). I ended up just twisting until it snapped the tab off. Since the tab is part of the ESIM, I didn't care if it got broke. The new one would replace it.

You did not specify which motor you have. I have the 5.7 Hemi. If you have the same, the part number for the ESIM is 04861959AA. You will also need the seal, 52129436AA. Cost me only $35 for both from my dealer and took all of 5 minutes to replace. So far, I have not had either code come back. Although I only did this a week ago and have not gone through a complete tank of gas yet. For the price, I think it's worth the try.

Here is a link to one for sale on eBay for reference only. Mind you this is NOT the one for the 5.7. It is for the 3.7L V6 but it looks the same.

Chrysler Jeep Dodge Esim Evaporative System Integrity Leak Module Mopar Factory | eBay

Another link for reference only, the ESIM on the charcoal canister. Again, not for our truck, this is for a Ram 1500, but this shows you pics of how it looks.

http://www.ebay.com/itm/DODGE-RAM-15...87204256&rt=nc

 

jsandvold,

Welcome to the forum.
Based on your explanation, I'd recommend to continue working with your dealer.
It sounds like the issue has nearly been resolved however additional review is needed.
Keep us posted with any news.

 

Agreed, as long as the dealer is paying for this. If not, you're paying them to troubleshoot, and they're failing miserably.

 

Hi Everyone -
Thank you for the replies! I took Coyote's advice and went to the Chrysler dealership I had been working with (terrible by the way) and purchased the seal and the ESIM module for about $50. My dad is a certified master mechanic and did the replacement in less then 10 minutes. Seal was a little tricky to get back in, but very easy fix for anyone who can unhook a sensor and plug back in the new one.

Unfortunately recommended I continue to go back to a dealership that has caused me issues is not helpful. They installed an engine and couldn't even get that part right so I think for all odd jobs like this I will leave it to my dad Luckily I am fortunate to have a resource such as this.

I will say that right after the sensor was replaced, I restarted my car, and the GAS CAP warning came on for a brief second and then disappeared and has not been back yet. This was coming on immediately after starting the car, even before the Check Engine light.

My dad cleared the Check Engine light code as well and that has not come back yet either. I will be back in here if anything else comes back but so far all is well and it feels good to know that such and easy fix for $50 took care of both lights and issues.

On a separate note if anyone with this vehicle gets the Low Engine Oil Pressure code and all is well with the vehicle, the dealership had to do a quick "flash" update on my vehicle to get it to go away. Hasn't come back yet so I am thinking this took care of the issue.

Hope this helps anyone that has been having the same problem.

opps...one more thing I forgot to mention was that you have to buy this part from a Chrysler dealership. The part numbers Coyote supplied are correct. Napa, Auto Zone, and O'Reilly's (at least in Portland, Oregon) don't carry them.

 

Glad the ESIM worked for you as well. So far the code hasn't returned for me. I hope this was a permanent fix for you as too. Keep us posted.

 

Well my P0456 (very small evap leak) code is back. It went away Sunday (just a few days ago) when my dad cleared the codes and it's back.

The P0457 code and the GAS CAP warning went away however and did not come back.

From my original post...I have had it smoke tested and no leaks found as well as replaced the gas cap with an OEM one from the dealership along with the replacement of the ESIM module.

Any other ideas on what could be throwing this code? So frustrating!

 

P0456 is typically one of the following:

1. EVAP purge system leak;
2. EVAP purge solenoid; or
3. EVAP system monitor switch.

It sounds like you've done two of these. If you're confident that the dealer properly performed the smoke test, this narrows it down pretty well for you.

 

Man. I was really hoping you had this one cracked as well. That sucks. The fact that a smoke test didn't find anything worries me. Unless it's leaking somewhere that is not easily seen like on the topside of the charcoal canister. Sorry to hear this.

 

Hey Everyone -
Sorry it has taken me so long to reply. My dad is just now having time to look at this issue.

Looking at the Purge Solenoid and the System Monitor Switch

Anyone have any links or resources on these two parts and where they are located on the vehicle?

Thanks!