Check Engine Light
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JK Newbie
Joined: Dec 2019
Posts: 15
Likes: 0
From: Diamondhead, MS
Check Engine Light
My check engine light recently came on and I know that this is common in these things. However, I also notice that the eco light that comes on when in optimal rpm's has not come on since this check engine light came on. Any ideas?
JK Jedi
Joined: Dec 2010
Posts: 5,642
Likes: 486
From: Knoxville
Turn your key forward to the run (not starting) position twice and on the third turn, leave it forward. Then post back your codes and we'll be able to help. It's unlikely the vehicle will give you eco advice if it's having trouble with the computer.
JK Junkie
Joined: Feb 2012
Posts: 3,499
Likes: 162
From: brick, nj
I would not say trouble codes are common. I had my 2012 for 8 yrs and 108,000 miles and I don't recall trouble codes except when the battery died. I hate that eco light. You know if you turn it off your Jeep will show you the radio station in that place.
JK Jedi
Joined: Jun 2013
Posts: 11,363
Likes: 2,089
From: Willow Park, TX
the P0455 and P0456 evap codes are a common thing IMO. Sometimes just don't get the gas cap on well after filling up, sometimes overfill can cause an issue. I always just clear em and unless they come back almost immediately I don't worry bout em. I would clear the code though so it doesn't reflect as a stored code. If you do not have a code reader, there's no reason to not own one. They are so cheap these days and they are extremely useful. Jscan app is very dynamic for a total of ~$35. Bluedriver is a great tool that costs more but can be used on any vehicle.
JK Junkie
Joined: Feb 2012
Posts: 3,499
Likes: 162
From: brick, nj
This reminded me that I did get a code once in my 2012. It was for the gas cap, however, the gas cap was not the problem. I simply fiddled with the hose that goes into the evap and the code went away and never came back.
JK Newbie
Joined: Feb 2016
Posts: 29
Likes: 1
From: Wentworth, NC
I had that code on my 12 and it was the gas cap. Due diligence says check all potential causes. If the gas cap is old, then a new gas cap might be warranted. Buy a Mopar one if you do change it, not worth getting an aftermarket one.
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JK Junkie
Joined: Feb 2012
Posts: 3,499
Likes: 162
From: brick, nj
Originally Posted by JAHII
Rob, does replacing the battery cause codes to come up? I just replaced my battery in my 2013 JK and a few days later I’ve got a gas cap code. Just wondering if that’s related.