Check gas cap light

[DaSOB]

I got a Check Gas Cap light on my 2015 Ram 5.7L. I just had the ESIM replaced about three weeks ago after getting a P0455 code. A few days ago, the Check Gas Cap light came on, and a couple of days later the MIL came on. I pulled a P0456 code with my scanner. I replaced the cap and cleared the P0456 code, but the Check Gas Cap light is still on, and the scanner won't clear it.

Before I run to the shop and spend another $130 for them to connect up their computer, I would like to get some input on this. Where should I go from here?

 

[Coramie]

I’ve replaced the ESIM twice on my ‘18 1500 and it’s fixed the codes both times. If a new gas cap and a new ESIM isn’t working, it could be a bad purge valve. I’ve heard that’s the second most common issue, with a faulty ESIM being the first. If neither of those address the issue, it would be time to smoke the line to see if there actually is a leak. At least that’s my understanding of the process.

 

[DaSOB]

I’ve replaced the ESIM twice on my ‘18 1500 and it’s fixed the codes both times. If a new gas cap and a new ESIM isn’t working, it could be a bad purge valve. I’ve heard that’s the second most common issue, with a faulty ESIM being the first. If neither of those address the issue, it would be time to smoke the line to see if there actually is a leak. At least that’s my understanding of the process.

I started and stopped the engine a few times, took the truck for a drive or two around the block, and the light went off. Looks like the new gas cap did the trick.