Is it battery, electronic or transmission?

[sandy.h]

I’ve owned my 2018 Jeep JL for about three years now. Almost the entire time it has given me issues. We were on a mountain trail the first time it happened which was the most frustrating thing ever.

Jeep revs and then a couple messages pop up. Only one of them I was able to read and remember. It read:

“Service transmission. Continue is D. Do not turn engine off until you have reached your desired location. You will not be able to shift again until serviced.”​

Whhhhhaaaaaattttttt!!!!!????? Then it tells me to shift to P then back to D. Welp, it doesn’t let me put it back into D. So now I’m stuck on this narrow only way up and down off the mountain bumpy AF trail. Longer story short, I finally decided I was gonna turn off the vehicle after checking under the jeep. Tried to start the jeep, it does nothing. Tried a few more times, same story. Waited a few minutes then finally it turned back on. Turned my ass around as soon as a I could.

Took it to the dealership, but now the check engine light isn’t on and no stored messages. They don’t know what’s wrong and they can’t find out because no codes are given. Over the next couple of years I’ve had that message a few times along with “Service Electronic Stability Control”. But wait a few minutes, after turning it off, and it works. Sometimes, but not all the time, it has kicked me out of gear and revved then put me back into gear. This happens when I’m driving at higher speeds. If it does that at lower speeds (Like in a parking lot), it tells me to shift into P then back into D. Then message pops up saying “Stop/Start Unavailable. Service Stop/Start System” and the traction control light comes on.

Ive taken the jeep to the dealership about 12 times over the last three years to get these problems fixed. But every time I take it in, no codes show. They did replace something in the transmission but that didn’t fix it. Noooooooowwwww, my jeep is no longer under warranty! ? Problem still happens. Not all the time but often enough. I cringe every time I hit a pothole, which happens very often here! Anybody got any clue of what it could be? So I could try to fix it myself instead of paying a $200 diagnostic fee for them to tell me they can’t fix a problem they can’t see.

12/05/2022 Update:

I replaced the aux battery two days ago. However, twice today I got into my jeep and tried to start it and engine doesn’t turn on. (Twice out of the seven times I’ve started my jeep today) Electronics turn on though, and it goes into “run” and stays stuck in run. Won’t let me shut the jeep off completely. Messages on the dash are:

“Service Electronic Stability Control”
and
“Service transmission. Continue in D. Do not shift or turn engine off until you have reached desired location. You may not be able to shift again until serviced.”​

If I wait about five minutes without touching anything, the messages disappear and it shows the speed. I press the stop/start button and engine turns on. These are problems that have happened before but it could happen once then won’t happen again for months. I’m wondering if I could have messed up when installing the new aux battery (I did it myself and it was quite difficult). I thought it might be a blown N3 fuse but I’m assuming if that was the case, the engine won’t turn over at all.

One more thing I forgot to note though! After I replaced the aux battery, the jeep would turn on, engine on, dash and display would turn on. Then all of a sudden dash and display turn off, but jeep is still on and running. When I replaced the aux battery I took the PDC apart, I thought maybe some fuses got messed up, they were all good. I then proceeded to tighten the four bolts holding the PDC together. Tried starting it again and it worked fine. Took it for a ride, no problems. Now two days later, we got problems!

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[Punkn89]

Snag a picture when it happens if possible. Have you modded your Jeep at all?

 

[sandy.h]

Snag a picture when it happens if possible. Have you modded your Jeep at all?

There is a 2.5” lift and 35s on the jeep. But that’s it. I just inserted photos of the messages that I had taken.

 

[Punkn89]

There is a 2.5” lift and 35s on the jeep. But that’s it. I just inserted photos of the messages that I had taken.

definitely sounds electrical, possibly a broken wire somewhere. I honestly wouldn’t know where to start though, someone else may chime in.

Get yourself an OBD reader so once you see that pop up, plug that sucker in.

 

[Punkn89]

https://www.jlwranglerforums.com/fo...e-in-d-do-not-shift-or-turn-engine-off.66440/

 

[58Willys]

Good chance it’s an electrical glitch. Open fuse panel top, press fuses in gently and make sure all fuses are firmly seated. If it’s not that, it could be a faulty connection/wire. Check all wire harness for rubbing, chafing, and make sure all harness connectors are connected properl.

 

[mysto]

stop/start unavailable will show any time *any* code is raised, so don't focus on that. The service esc might be the root cause code, loose wire or bad sensor. The dealer really should be able to see it.

@58Willys suggestion to seat the fuses is a very reasonable step

 

[kah.mun.rah]

How old is the aux battery?

 

[sandy.h]

How old is the aux battery?

I haven’t ever changed it so at least four years old.

 

[sandy.h]

stop/start unavailable will show any time *any* code is raised, so don't focus on that. The service esc might be the root cause code, loose wire or bad sensor. The dealer really should be able to see it.

@58Willys suggestion to seat the fuses is a very reasonable step

You would think but now it isn’t under warranty so they would charge $170 just to bring it in on top of whatever they think needs fixing. It’s incredibly frustrating! Since I’ve taken it in for the same issue over and over and over again, you’d think they’d just do it. ?

 

[kah.mun.rah]

I haven’t ever changed it so at least four years old.

I would start there. Whenever the aux battery would start to go out in my 2018 I would get all kinds of random warning messages (related to everything but the battery).

 

[Fudster]

I’ve owned my 2018 Jeep JL for about three years now. Almost the entire time it has given me issues. We were on a mountain trail the first time it happened which was the most frustrating thing ever.

Jeep revs and then a couple messages pop up. Only one of them I was able to read and remember. It read:

“Service transmission. Continue is D. Do not turn engine off until you have reached your desired location. You will not be able to shift again until serviced.”​

Whhhhhaaaaaattttttt!!!!!????? Then it tells me to shift to P then back to D. Welp, it doesn’t let me put it back into D. So now I’m stuck on this narrow only way up and down off the mountain bumpy AF trail. Longer story short, I finally decided I was gonna turn off the vehicle after checking under the jeep. Tried to start the jeep, it does nothing. Tried a few more times, same story. Waited a few minutes then finally it turned back on. Turned my ass around as soon as a I could.

Took it to the dealership, but now the check engine light isn’t on and no stored messages. They don’t know what’s wrong and they can’t find out because no codes are given. Over the next couple of years I’ve had that message a few times along with “Service Electronic Stability Control”. But wait a few minutes, after turning it off, and it works. Sometimes, but not all the time, it has kicked me out of gear and revved then put me back into gear. This happens when I’m driving at higher speeds. If it does that at lower speeds (Like in a parking lot), it tells me to shift into P then back into D. Then message pops up saying “Stop/Start Unavailable. Service Stop/Start System” and the traction control light comes on.

Ive taken the jeep to the dealership about 12 times over the last three years to get these problems fixed. But every time I take it in, no codes show. They did replace something in the transmission but that didn’t fix it. Noooooooowwwww, my jeep is no longer under warranty! ? Problem still happens. Not all the time but often enough. I cringe every time I hit a pothole, which happens very often here! Anybody got any clue of what it could be? So I could try to fix it myself instead of paying a $200 diagnostic fee for them to tell me they can’t fix a problem they can’t see.

Hi Sandy:

I can't definitely put my finger on the cause(s) of your problem.

I can say that JLs can act like they are demonically possessed when their batteries are in need of replacement. And you've got two in that 2018.

By virtue of simply the amount of time you've owned the vehicle I would say it time to replace those batteries even if they are in tip top shape, simply as a product of the minimal number of years you've had them in service, and who even knows if they were replaced by the dealer after purchase--it sounds like from the time line that you are not the vehicle's original owner.

The dealer should have tested the two batteries independently using something called a load tester. It's a device that doesn't simply take a battery's voltage at an instant in time, but rather, subjects the battery to charge and discharge (i.e. that which a battery does) to see how well it both delivers and accepts charge, something over time it will become defective at.

On one of your pictures I can see that the ESS off light in the EVIC (i.e. the dash display) is illuminated. This may have arisen from a failed attempt for you to crank the engine, followed by a second attempt that succeeded and turned that light on. Often this is reflective of a situation where the vehicle sees the second battery (the small ESS) battery as dead during a test of it in normal conducts at startup, and upon second crank attempt uses only the main battery to crank.

If that subsequent engine crank is successful that ESS off light in placed in the dash, the ESS battery is taken out of service by the vehicle and only the main battery is used until the next cold crank where a working/charged ESS battery is introduced under the hood.

Without going into details yet, enough material has been written on this forum about how and if to replace that ESS battery or even if abandoning use of that ESS battery and disabling ESS is best, to make the US Tax Code look like a short story.

Even if only the ESS battery is defective, unless you are willing to abandon its use, which will involve your willingness to not use the ESS system, both batteries should be replaced given how they are connected together under the hood.

Will this solve your issues? Maybe. Regardless, it's a necessary first step. I'm shocked of no reports at your end of the dealer not testing the batteries.

 

[58Willys]

Have the batteries load tested. If either fails, replace both. As other have said, your batteries are probably at the end of their useful life.

 

[Spank]

Looks like it's time to replace both batteries.

 

[Zandcwhite]

If it's a 2018 and the battery is still the original, I'd start there for sure.

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