4xe Check Engine Light Issue (CEL)

OINC

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Well. Mine came on at 891 miles, and I’m out on an isolated island with no real access to anything.

I suspect it happened because I plugged in last night outside in the rain and maybe a little water got into the charge port. Or there was a brownout, which happens all the time out here. Anyway, when I unplugged the light in the charge port was red (though it was charging fine when I left it).

ETA I’ve had mine for 15 days at this point and all the RRTs were applied before I picked it up, so that’s not the fix. And yes I’ve checked the fuses. And the gas cap (even though it has been a week since I got fuel).
Now that I'm back in civilization, I stopped in at AutoZone to get the codes read since the next available appointment at the dealer is two weeks out. It's the gas cap codes (P04EC/P04EE; https://static.nhtsa.gov/odi/tsbs/2021/MC-10198356-9999.pdf). I reseated and cleaned the gas cap; we'll see if the light goes out. I'm just glad it's not something major!

Apparently all the RRTs were NOT done when I picked up the vehicle, either -- 122 and 127 are still listed as outstanding. So I'll probably keep the appointment anyway.
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Skades 89

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I took delivery on 9/20. 375 miles later CEL is on. I have an appointment on Wednesday. 🤞
 

JeepCares

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Ours is part of the "high voltage cable" recall but have not had any issues yet fingers crossed.
Hi REDSEAL199,
We suggest getting the CSN performed. If you would like assistance while at the dealer, we are happy to help via private messages.

Rob
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JeepCares

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I took delivery on 9/20. 375 miles later CEL is on. I have an appointment on Wednesday. 🤞
Hi Skades 89,
If you are in need of additional support while in service, please let us know via PM. We can certainly have a case escalated for additional assistance while in service.

Rob
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bondijoe

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It took a month but my battery coolant pump finally came in and seems to have fixed my CEL issue. Glad to be back in my 4xe. Good luck to everyone.
 

JollieOllie

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Hello.

Not a complaint, just sharing with the group. My check engine light came on yesterday. After reading through this thread and looking at some videos on YouTube, I checked the gas cap, which was loose and not set properly. I put it on properly but no change. (On a side note, I found it hard to fill the tank previously, it kept clicking and shutting off, as if the tank was full, which it wasn't. I'm not sure if this has anything to do with anything but I thought I'd mention it.) I filled the Jeep with gas to the brim, closed the cap properly, now that i know that there is a fat end and a thin end and all is good. No more engine light.

FYI - in case it helps somebody.

PS - I am still taking it to the dealer to doublecheck the codes as I wanted to do the recall and the software updates anyway.

These things happen, all good! :)
 

sconrad24

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Hello.

Not a complaint, just sharing with the group. My check engine light came on yesterday. After reading through this thread and looking at some videos on YouTube, I checked the gas cap, which was loose and not set properly. I put it on properly but no change. (On a side note, I found it hard to fill the tank previously, it kept clicking and shutting off, as if the tank was full, which it wasn't. I'm not sure if this has anything to do with anything but I thought I'd mention it.) I filled the Jeep with gas to the brim, closed the cap properly, now that i know that there is a fat end and a thin end and all is good. No more engine light.

FYI - in case it helps somebody.

PS - I am still taking it to the dealer to doublecheck the codes as I wanted to do the recall and the software updates anyway.

These things happen, all good! :)
Yep happened to me yesterday too. CEL when I started the Jeep to come home after work. I stopped at the dealer on my way home. Gas cap not seated. They cleared the code and got me in and out in 10 minutes. Now I know to line up fat and skinny ends.
 

FloridaLarry

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I took delivery on 9/20. 375 miles later CEL is on. I have an appointment on Wednesday. 🤞
No issues yet, but I got mine 5 days before you and have 650 miles (half was gas only, on the ride home from dealer). I was hoping all gremlins were taken care of at the factory with the latest sw updates. :(
 

sconrad24

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No issues yet, but I got mine 5 days before you and have 650 miles (half was gas only, on the ride home from dealer). I was hoping all gremlins were taken care of at the factory with the latest sw updates. :(
FWIW, I used my time at the dealer to chat with the tec running the code. He mentioned that since mine was a September build, it would be a “second generation ” should not have issues. He said first gen were total messes and that everything seems to be covered for the second gen. He didn’t breakdown what dates are the cutoff for first and second gen. I’ve never heard of generations for 4xe so take it with a grain of salt. I still asked for any recalls or RRTs for mine and he said there’s nothing. So atleast fixes are being applied to the line.
 

michail

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When I go in it seems like the 4xe is a new magical thing they haven't seen. Then I ask about all the problems and they say they haven't seen any come in, lol.

My build date is April 1st but mine hasn't been a mess. However, I did need to have the HV cable oring replaced. Also had one highway shutdown.

Much of the early stuff seemed to be related to cables and plumbing just not being installed correctly.

I suspect "2nd gen" has improved manufacturing process/QC on those items along with all the software updates.
 

JollieOllie

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Hello.

Not a complaint, just sharing with the group. My check engine light came on yesterday. After reading through this thread and looking at some videos on YouTube, I checked the gas cap, which was loose and not set properly. I put it on properly but no change. (On a side note, I found it hard to fill the tank previously, it kept clicking and shutting off, as if the tank was full, which it wasn't. I'm not sure if this has anything to do with anything but I thought I'd mention it.) I filled the Jeep with gas to the brim, closed the cap properly, now that i know that there is a fat end and a thin end and all is good. No more engine light.

FYI - in case it helps somebody.

PS - I am still taking it to the dealer to doublecheck the codes as I wanted to do the recall and the software updates anyway.

These things happen, all good! :)
Here is my update:

After filling up the tank and properly closing the gas cap the light came on one more timre during one drive, but that's it.

I took the Jeep into the dealer for the CEL and their response was to perform the RRT 21-137 14600596 Cap, fuel filler tank filler - Replace Tether, Fuel filler cap. If I don't respond back to this thread then all is good with the CEL.

They also performed the Recall Y46 High Voltage Cable Connector Seal. They checked the P1 and P2 connectors and replaced both seals.

Finally they did the software updates:
RRT 21-122
RRT 21-123
RRT 21-124
RRT 21-126
RRT 21-127

I have only noticed two changes so far; the Max Reg button now stays on, even if I turn off the Jeep and turn it back on again (YAY) and the shifting, especially downshifting is much smoother.
 

Lowcountry4XE

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Picked up my Sting Gray Sahara at the end of August and am loving it so far. First Wrangler for me. Only problem so far is a Check Engine Light (CEL) that I picked up a couple of weeks ago. I had reseated all the fuses after I bought so I checked the gas cap and it was completely off, just bouncing around behind the closed fuel door. Installed and tightened but no luck on clearing the CEL after a few drive cycles. I had the typical OBDII codes for a gas cap, small and large evap leak. After doing some research I tried all the fixes I could find and learned a few things about the 4XE gas cap that I wanted to share,

1. After some troubleshooting I concluded that the gas cap was not seating tightly enough (I tried all the tricks like a little grease on the o-ring). I tried a "generic" jeep gas cap in the 4XE and it also did not work. Still had the evap codes in even though the new cap was installed tightly. The 4XE gas cap is unique in that it is not vented. Most vehicle gas caps have a spring loaded pressure relief built into cap that maintains the fuel tank pressure at the optimum level (also protects against a vacuum implosion). The 4XE cap does not have the pressure relief feature. It is a solid piece of plastic. Look at the internal end of the 4XE cap and compare to another car to see the difference (and to find another 4XE easter egg). The 4XE fuel system runs at a higher pressure than a normal auto fuel system and the relief feature is built into the fuel system not in the cap.

2. The 4XE cap can also only be inserted in only one position. Most modern gas caps have tabs at the end of the threads that fit into slots in the fuel filler neck. So to get a good seal you have to insert the cap with the tabs lined up with the slots in fuel filler neck before you tighten the cap. The tabs tend to be the same size allowing you to insert at each half turn while you are rotating the cap. The 4XE cap has a very large tab and a very small tab so that you can only install at one point. I'm not really sure why the 4XE cap is different in this regard.

3. Gas caps have a built in over-tightening feature (the clicks) that prevent you from tightening the cap so much that it becomes difficult for you or someone else to open. The clicking sound should be generated when the gas cap threads are at the right torque in the fuel filler neck but it is a fairly crude system. The torque value is set by bending some plastic tabs on two rotating plastic disks that allows the outer cap to rotate separately from the inner cap when the right torque is reached. The clicks are the sound of the plastic tabs slipping and snapping back. I could feel that my cap wasn't getting very tight, it would start clicking almost as soon as I felt any torque when I was tightening. The new generic cap felt much tighter.

4. The last point on the cap is the long tether that is originally installed on the gas cap. The long tether can get caught in the fuel filler neck when you are threading on the gas cap causing a poor seal and CEL. There is a recall for the gas cap that replaces it with a new cap with a shorter tether.

With that info in mind, I made an 7:30 am appointment at my local Jeep dealer and brought in for a new cap. I told them exactly what I thought the problem was, demonstrated the loose cap, and left expecting to get it serviced that day. One benefit of the uconnect vehicle tracking is that I could tell where my Jeep was at the dealer and at 2:00 pm it was still sitting outside. I called and my service rep said they could not get to it that day (why have appointments if they can't even get the vehicle in for diagnosis). I am very impatient with service centers so I said I would come get and just order a new 4XE cap myself. At this point I still had the CEL in.

I picked up my 4XE and brought home and decided to see if I could fix the cap somehow to really confirm that the cap was the problem. I disassembled and tried a few things but no luck. So as a temporary fix I inserted just the inner cap (the threaded portion of the gas cap) and tightened it down. Ran the jeep and checked the codes and was able to clear them this time! Ran the jeep for a couple of days and no problems. Definitely is a bad cap. Ordered a new cap from the dealer ($38 and backordered of course) and am running now with just the inner cap. Luckily I don't put gas in it often!! I will attempt to get the dealer to pick up the cost of the cap but I'm sure it will be too much of a hassle at this point.

Sorry for the long post, but given all the gas cap problems I've seen posted here I figured the information I found might be useful for others.
 
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