P0456 code question

I woke up this morning with this code and it's for a small leak detected in the evap system. My research says to replace the gas cap first so I ordered one that'll be here tomorrow. The code said it was temp and I cleared it and it has stayed off but I want to be prepared for if it comes back on. Is this potentially going to be an expensive problem? I have a 2013 1500 with the hemi and I've gotten codes speratically throughout the years telling me the gas cap was loose but it always went away on its own.

On my '15, it turned out to be the ESIM down by the gas tank.

I did my gas cap first, but that wasn't it.

I just had this code on my chrysler pacifica and I replaced the EVAP purge valve and the code went away.

The code has not returned since I cleared it this morning but I'm replacing the gas cap since it's cheap and I've wanted to replace it anyway. I also ordered the purge valve because it's so easy to get to and replace. Both of those will be replaced tomorrow (assuming I can figure out how to disconnect the wire harness) and if the code comes back I'll replace the leak detector on the gas tank which seems a little more difficult to get to but is a cheap part.

ramtruckrob said:

The code has not returned since I cleared it this morning but I'm replacing the gas cap since it's cheap and I've wanted to replace it anyway. I also ordered the purge valve because it's so easy to get to and replace. Both of those will be replaced tomorrow (assuming I can figure out how to disconnect the wire harness) and if the code comes back I'll replace the leak detector on the gas tank which seems a little more difficult to get to but is a cheap part.

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I had it a few years ago. It ended up being some deep scratches around the metal filler neck opening.

ramtruckrob said:

The code has not returned since I cleared it this morning but I'm replacing the gas cap since it's cheap and I've wanted to replace it anyway. I also ordered the purge valve because it's so easy to get to and replace. Both of those will be replaced tomorrow (assuming I can figure out how to disconnect the wire harness) and if the code comes back I'll replace the leak detector on the gas tank which seems a little more difficult to get to but is a cheap part.

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If it returns after you replace the gas cap and purge valve definitely look into the ESIM attached to the charcoal canister on top of the fuel tank. It’s pretty cheap and they do go bad. It’s a PITA to get at and helps if you are young, thin, in shape with long thin fingers, small hands and the grip strength of a gorilla lol
Do it when you have very little gas in the tank and lower the tank a few inches by loosening the retaining/mounting straps. It’s the white thing in the pic.

Check all the hoses on top of the tank for any cracks,splits or wear thru abrasions. Sometimes critters will make a meal from hoses also.

I looked underneath at what I could see on top of the tank and it all looked good other than a possible broken clip that I couldn't confirm but the hose felt like it moved around more than I'd expect. I couldn't see anything obviously leaking or broken though.

My wife just took the truck to work and the light still didn't come back on.

Atcer2018 said:

If it returns after you replace the gas cap and purge valve definitely look into the ESIM attached to the charcoal canister on top of the fuel tank. It’s pretty cheap and they do go bad. It’s a PITA to get at and helps if you are young, thin, in shape with long thin fingers, small hands and the grip strength of a gorilla lol
Do it when you have very little gas in the tank and lower the tank a few inches by loosening the retaining/mounting straps. It’s the white thing in the pic.

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I don't know if it makes a difference but I have the larger 32 gallon gas tank and the one video I saw of someone replacing this it looked different. I couldn't see mine from under my truck.

Atcer2018 said:

If it returns after you replace the gas cap and purge valve definitely look into the ESIM attached to the charcoal canister on top of the fuel tank. It’s pretty cheap and they do go bad. It’s a PITA to get at and helps if you are young, thin, in shape with long thin fingers, small hands and the grip strength of a gorilla lol
Do it when you have very little gas in the tank and lower the tank a few inches by loosening the retaining/mounting straps. It’s the white thing in the pic.

Click to expand...

I just figured it out. I was planning to replace the leak detection pump and not the ECIM. I think I looked at the ECIM and not the pump since I was at the front of the tank and apparently the pump is on the back drivers side of the tank.

ramtruckrob said:

I just figured it out. I was planning to replace the leak detection pump and not the ECIM. I think I looked at the ECIM and not the pump since I was at the front of the tank and apparently the pump is on the back drivers side of the tank.

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Yeah the ESIM is on the back corner of the tank near the spare tire on the 26 gallon tank.

I'm having similar issues and this is a fairly recent post so I figured I'd throw my hat in the ring here rather than starting ANOTHER P0456 post! lol!

2012 Tradesman, 4.7L, 4x4, Rambox, Flexfuel, no mods

I've had this truck since new in 2012 (maybe late 2011?). I've still only got 70k due to short commute 4 days a week and wife doesn't like my driving.

Recently had evap system fault code and now "GASCAP" on the odometer at startup with the little pictogram of the gascap. I replaced the cap with a cheapo from the local parts store. Still faulted a couple weeks of use later. After filling the tank I had a puddle of gas in the driveway that caused me a little uptick in my concern meter. I crawled around under but couldn't see exactly where it came from. I dropped the tank and found a crack where the fuel line comes out of the pump hat. $350 later I've got a new fuel pump in there but still have the codes, no puddle though, but that was a one-time thing so far. After a little Youtube University I find the white sensor box on the back of the charcoal canister could be the problem. I pull it out and sure enough clackity-clack when you shake it and it had a big crack and corroded wires at the sensor side of the plug. New sensor on order.

Replaced the sensor today, cleared the codes with a reader, drove around a bit, turned it on and off about ten times. Still has the GASCAP odo code but no check engine light indicating a code. After a bit of reading it seems this has to maybe be at a certain level of full in the tank and a certain amount of engine cycles before this clears, even if it is actually already fixed? How many cycles? How long? What conditions must be met? My cheapo code reader can't initiate the evap test it needs to pass to quit spitting the code at me....