2018 Wrangler JLU Multiple Alarms & Crazy Scale 10

[KingSpaceCow]

Sudden drastic behavior change this week with my 2018 Wrangler JLU Sport 4-Door 3.6L. No warnings. I am in Florida and we did have our first cold week or two. Obviously not the Christmas present I was wanting. When I start the vehicle all visual alarm senors or at least all I am familiar with come on and will not clear. The front windshield wipers start and will not stop. Yes checked toggle position. Transmission will not allow to change from park. Power steering does not works. Cannot turn off vehicle. Have to disconnect negative battery terminal to shut down. Front message center seems to be rebooting/recycling. Some times shows Rubicon (which it is not) some times shows wrangler. While jeep is running OBDII is not functional.

Things I have tried. Initially charged main battery, replaced main battery as it was the original and H6 with upgraded H7, removed Aux Battery and F42 fuse. Tested High amp fuse assembly. Everything passed continuity with multi-meter. Going to double-check after adding back aux battery.

Things that work or seem to work: Headlights, Stereo 5" screen, climate control.

I have charged the aux battery now and it is reading 12.8V. Going to try installing it back in and putting fuse F42 back in place. Simply for lack of other ideas.

Help appreciated as towing it to dealer or shop is like coal in my stocking...!

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[sailscall]

Have you ever replaced any of your batteries?

 

[sailscall]

It sounds like you’re going down the right path.

 

[KingSpaceCow]

Have you ever replaced any of your batteries?

Replaced main battery today. Aux battery replaced once. Current is 2-3 years old. Was going to opt for Aux Battery delete but see some other posts about firmware doing an ESS check so not sure if that is an option or how to validate.

 

[Packnbeer]

2 to 3 years is all an Aux lasts but I would really lean towards the main for this. With that being said, I would replace them both because both are at their life's end

 

[rohdawg]

2 to 3 years is all an Aux lasts but I would really lean towards the main for this. With that being said, I would replace them both because both are at their life's end

He said he just replaced the main.

@KingSpaceCow I’d try a new aux since your main is new, double check all your connections since you’re coming back from the aux delete, give it a try afterward and see what happens.
I see you checked high amp fuse array. That’s usually the other culprit.

 

[KingSpaceCow]

Gave up last night after put the new main battery and old aux battery and fuse F42 back in place. Immediately had the same issue after starting. When I disconnected the main negative jeep continued to run albeit felt a little angry. Was able to get it to finally stall out but turning off lights, climate control, radio, etc. Crazy sounding I know. I left the jeep overnight with the negative disconnected to the main battery. This morning began prep to check can bus connections by removing the glove box. Connected back the main battery. Instead of cranking the jeep put it in "run" because I was previously able to have the same issues and easier to get it stop. Jeep was sane for a few minutes. I was able to use the message center to check voltage and it read 12.2V. That seems low almost like the main charged the aux battery. just not sure how it did that with the negatives completely removed from the main. The jeep was sane for a couple more minutes. Enough for me to read codes. Everything was a communication message, Can Bus, TCM, powersteering, etc. Just when I thought it was going to behave it started glitching and going crazy like always. Going to replace aux battery just to rule it out. Would prefer just to do the aux delete but not sure how to confirm firmware dependency on the aux battery is or is not a thing.

 

[DWS44]

When you tried the AUX delete, after you disconnected the battery and pulled the fuse, did you disconnect the negative cable from the main battery to clear all the existing codes? Mine wasn't in near as bad of a shape as yours, regarding warning lights, but when I finally deleted mine, it had been throwing the "Service Start/Stop" and I had to disconnect the main battery to clear that afterwards. Just a thought...good luck chasing it!

 

[JerseyJeff]

You need to possibly replace your canbus. Do a search in the forum on your canbus. Also check all your grounds on the body and frame. It's NOT your batteries

 

[KingSpaceCow]

You need to possibly replace your canbus. Do a search in the forum on your canbus. Also check all your grounds on the body and frame. It's NOT your batteries

The batteries were more proactive than anything else due to their age. I ordered and finally received the 20 Post Canbus connector. Just swapped it out and unfortunately the same issue. All sensor lights come on, wipers come on, message indicator states No Bus. Can't even turn off vehicle. Guess I will check the grounds but not sure how many there are to check other than mains by the battery.

 

[rvbuilder70]

Sudden drastic behavior change this week with my 2018 Wrangler JLU Sport 4-Door 3.6L. No warnings. I am in Florida and we did have our first cold week or two. Obviously not the Christmas present I was wanting. When I start the vehicle all visual alarm senors or at least all I am familiar with come on and will not clear. The front windshield wipers start and will not stop. Yes checked toggle position. Transmission will not allow to change from park. Power steering does not works. Cannot turn off vehicle. Have to disconnect negative battery terminal to shut down. Front message center seems to be rebooting/recycling. Some times shows Rubicon (which it is not) some times shows wrangler. While jeep is running OBDII is not functional.

Things I have tried. Initially charged main battery, replaced main battery as it was the original and H6 with upgraded H7, removed Aux Battery and F42 fuse. Tested High amp fuse assembly. Everything passed continuity with multi-meter. Going to double-check after adding back aux battery.

Things that work or seem to work: Headlights, Stereo 5" screen, climate control.

I have charged the aux battery now and it is reading 12.8V. Going to try installing it back in and putting fuse F42 back in place. Simply for lack of other ideas.

Help appreciated as towing it to dealer or shop is like coal in my stocking...!

My wife also has a 2018 jeep. Sahara had multiple issues, not going into gear, brakes, locking up, the cluster going off,com, the ABS module was reading bad the dealership programmed it, thinking it would solve the issue, so what we found out so far as of the second day of January 2024 is the front wiring harness was pretty much laying on a hotspot on the motor, causing the front wiring harness to short out which causes all these issues, it is absolutely not the batteries. We change them way before this started thinking that would solve it. That was not it, it was a passport designed by Fiat Chrysler, and a lot of dealerships are denying the claim because it intermittently shows up on the computer and then goes away , and if it does not show up, they refuse to pay for it. Do not give up start getting pushy and demanding that you get some help do it online on Twitter on Facebook and start raising a major shit storm. We finally got ours back almost 6 months later Today and let’s hope this piece of crap starts working better than it has been. Good luck. I wish you well.

 

[mwilk012]

You have a failed component on the can network, drag it to a shop that can fix it. If you’re just curious, start unplugging stuff. Start at the power steering pump.

Do you have anything aftermarket attached to the OBD port or SGW?

 

[KingSpaceCow]

My wife also has a 2018 jeep. Sahara had multiple issues, not going into gear, brakes, locking up, the cluster going off,com, the ABS module was reading bad the dealership programmed it, thinking it would solve the issue, so what we found out so far as of the second day of January 2024 is the front wiring harness was pretty much laying on a hotspot on the motor, causing the front wiring harness to short out which causes all these issues, it is absolutely not the batteries. We change them way before this started thinking that would solve it. That was not it, it was a passport designed by Fiat Chrysler, and a lot of dealerships are denying the claim because it intermittently shows up on the computer and then goes away , and if it does not show up, they refuse to pay for it. Do not give up start getting pushy and demanding that you get some help do it online on Twitter on Facebook and start raising a major shit storm. We finally got ours back almost 6 months later Today and let’s hope this piece of crap starts working better than it has been. Good luck. I wish you well.

You have a failed component on the can network, drag it to a shop that can fix it. If you’re just curious, start unplugging stuff. Start at the power steering pump.

Do you have anything aftermarket attached to the OBD port or SGW?

Nothing added to OBD port or SGW. Your jeep whispering skills of power steering though may be on point.

Today I started isolating each cable going to the 20-post can bus. Pull one pin....wait 2 minutes...does jeep get angry yes/no...then go pull negative to turn off jeep...put pin back...try next pin...i just about given up and then I pulled this one and jeep ran like normal. I now have a Service Power Steering message and red steering wheel light and service engine light. Going to look for wiring diagram to confirm this is power steeing connector. Assuming it is not sure if that is a faulty connector or power steering component failure.

 

[rvbuilder70]

Umm no I don’t, we checked behind the glove box and it was not it, DEALERSHIP ORDERED A NEW FRONT HARNESS, the harness was touching something hot n shorted it out.. it’s been replaced and fixed..

 

[KingSpaceCow]

Umm no I don’t, we checked behind the glove box and it was not it, DEALERSHIP ORDERED A NEW FRONT HARNESS, the harness was touching something hot n shorted it out.. it’s been replaced and fixed..

Not quite sure which response you were replying to but understood...my reply was for mwil012's comments which were scarily on target

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