My 2020 Jeep Rubicon “JLUR” could have killed me and my family this weekend.

OP
OP

Fsttanks

Well-Known Member
First Name
Tony
Joined
Jul 15, 2020
Messages
358
Reaction score
719
Location
Palm Springs Ca.
Vehicle(s)
2013 JKU / 2014 JK / 2020 JLUR
anything from Friday?
Nothing except it is still in the “bay”. It will be there “best guess” until Tuesday.

So more then a week is very telling that something more is wrong then just a bad battery or under performing alternator. Both are easily replaceable.
Advertisement

 

WranglerMan

Well-Known Member
First Name
Will
Joined
May 8, 2018
Messages
3,283
Reaction score
2,413
Location
Katy Texas
Vehicle(s)
2018 Wrangler JLU Sahara
Occupation
Gas Pipeliner
Vehicle Showcase
1
I used to see 14+ all the time on my stock batteries and even after driving for a few hours it would drop to maybe the mid 13’s on the display, the only time I saw 12.7-12.9 was coming off a charger and once parked for a day or two it would be right back up to the 14+ but never had any staring issues and have ESS disabled.

When I first got my 2018 JL 3.6 auto the voltsge would display anywhere from 12.9-14 while driving and if it was say in the low 13’s and I would slow down the voltsge would ramp up to over 14 and once stopped would drop back down and I was advied by the tech ppl from the dealer that’s the smart charging system and it throws the voltage the system needs but over time mine just kept creeping up and had the factory main battery replaced once.

Fast forward a few years i went to a dual battery system and had the aux ESS battery removed and now have two 64 ahr full size AGM batteries so 128 ahr 12 volt system and it’s been in almost a month and after it’s been parked for several days upon startup it’s over 14 but within 30 mins of driving its in the mid to low 13’s and after maybe 90 mins of driving it’s down around 12.7-12.8 and I have done two weeks worth of voltsge checks after it’s sat for 24 hrs and my resting voltage so far has never been less than 12.6 on either battery.

I know there are some that say seeing 14+ volts all the time is normal and I have to say no it’s not normal, from my understanding of talking to several more knowledge ppl than me the smart charging systems of these newer vehicles only allow the alterantor to throw out the voltsge needed to keep your batterie(s) charged so if you are seeing 14+ all the time then the IBS is never seeing that the batteries are charged to the required voltsge to allow the alternator to back off, this would be the same as unplugging the IBS so it throws a contact 14+ volts all the time so its kinda like it was back in the old days when the vehicle was running and you put a meter on your battery you were supposed to get 14+ and with it shut off supposed to be 12.6 range and this was an indication that your charging system was working correctly but these new vehicles apparently monitor the voltage and only throw what’s needed to maintain the batteries at the correct charge.

Im so glad the OP got thru this safely and hopefully gets resolved by the dealer but with these newer vehicles with all their computer systems that look at EVERYTHING and shut down systems if one thing is wrong is a bit much and in some cases like this make the problem worst.

Is my system better than the stock system ......who knows but in my research it’s a step up from what I had with the two disimliar batteries that i think complicate things and then you throw in the IBS that monitors the batteries and then a relay that separates them during ESS events and it all starts to get complicated.
 
Last edited:
OP
OP

Fsttanks

Well-Known Member
First Name
Tony
Joined
Jul 15, 2020
Messages
358
Reaction score
719
Location
Palm Springs Ca.
Vehicle(s)
2013 JKU / 2014 JK / 2020 JLUR
I used to see 14+ all the time on my stock batteries and even after driving for a few hours it would drop to maybe the mid 13’s on the display, the only time I saw 12.7-12.9 was coming off a charger and once parked for a day or two it would be right back up to the 14+ but never had any staring issues and have ESS disabled.

When I first got my 2018 JL 3.6 auto the voltsge would display anywhere from 12.9-14 while driving and if it was say in the low 13’s and I would slow down the voltsge would ramp up to over 14 and once stopped would drop back down and I was advied by the tech ppl from the dealer that’s the smart charging system and it throws the voltage the system needs but over time mine just kept creeping up and had the factory main battery replaced once.

Fast forward a few years i went to a dual battery system and had the aux ESS battery removed and now have two 64 ahr full size AGM batteries so 128 ahr 12 volt system and it’s been in almost a month and after it’s been parked for several days upon startup it’s over 14 but within 30 mins of driving its in the mid to low 13’s and after maybe 90 mins of driving it’s down around 12.7-12.8 and I have done two weeks worth of voltsge checks after it’s sat for 24 hrs and my resting voltage so far has never been less than 12.6 on either battery.

I know there are some that say seeing 14+ volts all the time is normal and I have to say no it’s not normal, from my understanding of talking to several more knowledge ppl than me the smart charging systems of these newer vehicles only allow the alterantor to throw out the voltsge needed to keep your batterie(s) charged so if you are seeing 14+ all the time then the IBS is never seeing that the batteries are charged to the required voltsge to allow the alternator to back off, this would be the same as unplugging the IBS so it throws a contact 14+ volts all the time so its kinda like it was back in the old days when the vehicle was running and you put a meter on your battery you were supposed to get 14+ and with it shut off supposed to be 12.6 range and this was an indication that your charging system was working correctly but these new vehicles apparently monitor the voltage and only throw what’s needed to maintain the batteries at the correct charge.
This is pretty much how it was explained to me as well by the “build shop” I used on my JK and was planning to use on my JL the first of Dec.

They also said 12-14 volt range is normal, but it is worth asking the dealership to test the alternator.
 

WranglerMan

Well-Known Member
First Name
Will
Joined
May 8, 2018
Messages
3,283
Reaction score
2,413
Location
Katy Texas
Vehicle(s)
2018 Wrangler JLU Sahara
Occupation
Gas Pipeliner
Vehicle Showcase
1
This is pretty much how it was explained to me as well by the “build shop” I used on my JK and was planning to use on my JL the first of Dec.

They also said 12-14 volt range is normal, but it is worth asking the dealership to test the alternator.
12-14 volts is normal on these smart systems, I’m not sure why engineers decided to go the route of a smart charging system over the standard that was used over so many years but I’m sure it has to do with fuel economy by allowing the alternator to put less load on the system and who knows what else but again it all comes down to making these vehicles more efficient with the added demands of all the things we want.
 

WranglerMan

Well-Known Member
First Name
Will
Joined
May 8, 2018
Messages
3,283
Reaction score
2,413
Location
Katy Texas
Vehicle(s)
2018 Wrangler JLU Sahara
Occupation
Gas Pipeliner
Vehicle Showcase
1
This is pretty much how it was explained to me as well by the “build shop” I used on my JK and was planning to use on my JL the first of Dec.

They also said 12-14 volt range is normal, but it is worth asking the dealership to test the alternator.
I would say if the alternator say puts out 14+ volts after the jeep has been parked a few days is normal but then after it’s been running awhile the voltage on the EVIC display plus what you meter directly at the battery should slowly drop as the voltage on the battery gets closer to a full charge on it and that to me seems normal but if it stays at 14+ then from the info I have gathered there is possibly a issue with one or both batteries or some other part of the system like the IBS but I’m not honestly educated enough to give scientific or design info to back this up and all I am basing my info on is how smart charging was explained to me.

Here is some info I found very useful, I find F and G is supposed to be the norm and it’s what I saw when I first got my JL then again after I went to a dual battery system, I’m not saying going to a dual made it all better but it seems so far to have restored the operation to how it was designed.

https://www.redarc.com.au/alternator-vs-fixed-alternator
 

JimSa

Active Member
First Name
Jim
Joined
Oct 3, 2019
Messages
30
Reaction score
18
Location
Washington
Vehicle(s)
2019 JLU Rubicon
My 2020 JLU makes a popping sound through the speakers just before it shuts off without warning....it has done this a hand full of times since I put about 5k miles on it. Soon after the popping, (seconds)it reboots and comes back on but it has me worried just the same. There is no doubt that the electronics in these cars are going to be troublesome in the coming years. Reminds me of the Audis and how troublesome they used to be since the late 80's or maybe a bit earlier. You probably have bad connection most likely somewhere along the wires.
It may not be the speakers. Mine does it too, but continues to do it after the door harness is unplugged, so it's probably not electric. Worth checking.
 

HDinkH

Well-Known Member
First Name
Holly
Joined
Jul 25, 2019
Messages
4,096
Reaction score
40,810
Location
North Carolina
Vehicle(s)
2018 Wrangler JL 2.0
This is a STRONG WARNING to all Jeep JL owners!
3C3EE3B8-D2DA-486D-A813-4B3E154E5553.jpeg


The following is a short summarization of the event, some details have been left out and will be discussed with Jeep before I add them.

This weekend while taking a short family trip in our five month old 2020 Jeep JLUR we had TWO COMPLETE computer failures both without ANY warning.

The first was at a busy intersection the engine shut down and ALL the instruments and infotainment system went crazy included the SOS which started sending alerts that could not be stopped. I had NO ability to activate the hazards lights to warn other vehicles behind me or any ability to restart the engine. Twice we were almost rear ended so when it was safe enough I had my family exit to safety. My Jeep remained immobile in the intersection for almost 10 mins. At which point the computer system reset and I was able to move the Jeep to a safe location. After the incident there were no engine warning light of any kind and all the system were back to work as normal.

Thinking this was a one off glitch we continued on our trip. Well that was a huge mistake. Not much more then 10 min later while driving at freeway speeds there was another COMPLETE computer failure and total loss of ALL vehicle control. The steering all but froze up, engine was sputtering and loosing power worst the brakes were NOT working! All this on top of the other instruments going crazy. I managed with some effort to muscle the steering wheel enough to get the Jeep over to the extremely small “emergency lane” but then had NO brakes to stop with and our speed at this time was around 50mph. I was literally standing on the brake pedal and it was having almost no effect. I ended up having to use the “E” brake to stop our Jeep!

Once stopped, again NO “hazard lights” could be engaged and NOTHING worked! So now we were half in and half out of the traffic lanes. I carry flares and being this had just happen a few minutes early I was thinking about them so I deployed them to warn traffic and hopefully not get rear ended by a high speed passerby.

15 or so minutes later the computer system once again reset? I was then able to move the Jeep off the freeway. This time the “check engine” light was on. Seeing this I though REALLY NO F’N KIDDING.

Needless to say Jeep had a call from me and I have filed a report with the NTSB. Had either one of these incident occurred just a short time early as we had driven through a high speed (70mph) section of winding mountain roads I would not have been able to steer or brake sufficiently enough to have avoided a major crash. Fortunately I am a trained EVOC driver with decades of high speed and off-road skills to draw from. Had my wife or son or anyone with far less experience “behind the wheel” been driving when the last incident happen there is no way they could have safety made it off to the side of the road. Hell I was shaking and almost S**T my pants. I have had failure of steering and brakes before while on the job in other vehicles, but NEVER all the major systems at the same time let alone while at 70mph.

In more then 35 years of drive both personally and as a professional I have never been scared of driving a vehicle until today. I will never trust my JLUR again until Jeep can 100% in writing guarantee me this will NEVER happen again!!!

I don’t think the majority of JL owner actually realizes just how much of their Jeep is controlled solely by the one computer with no backup and that they have no real control over their vehicles except which the computer grants them. So be aware if your computer fails you are just along for the ride. And it’s a scary one!!!

P.S. Yes I am aware there have been other threads on similar topics. But none state the real danger involved. The Jeep was towed to my local dealerships where it will sit until ?. It is not a battery issue as both show full charges and voltage.

Your thoughts and constructive input are welcome.

EDIT NOTE:
1) This JLUR is a standard 3.6 with automatic transmission.
2) The ESS was turned off via the dash off button in both incidents. Always turn it off when I start the Jeep.
3) The tires are 315/70/17 BFG AT2.
4) NO computer “chip” mods were done.
5) The infotainment system is the Alpine with 8.4 screen.
Is your radio after market?

Problems started with my 2019 Sport eight days/228 miles after purchase. Jeep narrowed it down to the factory radio except the problems continued and worsened after they replace that radio. 10 times in the shop, 3 times towed before I dumped it at Carmax.

I really hope you have better luck with FCA than I did. That's really scary.
 

JimSa

Active Member
First Name
Jim
Joined
Oct 3, 2019
Messages
30
Reaction score
18
Location
Washington
Vehicle(s)
2019 JLU Rubicon
What happened here sounds like a power issue/failure. Some kind of a short. Possibly a short on the network (CAN bus) wires. Make sure they check the battery and major cable connections. I'm sure they will, but make sure you ask them anyway.

I've seen systems go crazy like that from a very low, almost dead, battery. Windshield wipers just started going by them selves and wouldn't stop, vehicle wouldn't start, dash flashing crazy. We had to disconnect the battery to get it to stop. Computers don't like to work correctly without the correct amount of power.
Exactly. I just got through dealing with a similar issue on my JL. The EPS was replaced with PSC hydraulic steering and ram. The CAN-BUS C3 (EPS connection) was shorting out and the JL went absolutely nuts with every system failing. I couldn't even turn the JL off. I had to disconnect both grounds at the battery to turn it off. While the EPS had been removed and replaced with aftermarket parts, what I found is that even on the stock JL the C3 connections at the EPS are not fully sealed, and Start/Run relay power could short to CAN C3 C+ C-. Similarly, some owners have reported issues with the electrical connections on the stock JL sway bar disconnect. Looking at my sway bar disconnect, the corrugated wire loom is pulling out, so I wouldn't be surprised if that becomes an issue at some point too. At a high level, the design flaw is that there isn't any redundancy and/or safety mechanism to shut a circuit down if it's misbehaving. Any shorting/grounding can knock the whole CAN-BUS out. It' becomes a weakest link problem and you tend to lose everything at once. Weakest link => Most Dangerous Situation. Not good.
 

cb4017

Well-Known Member
First Name
Cliff
Joined
Jul 27, 2019
Messages
164
Reaction score
207
Location
Northern Nevada
Vehicle(s)
2021 Gladiator Sport
Occupation
Retired
Wow! OP, glad you and the family are ok. Subscribed to see how this is resolved.

Got to say once I lose confidence in a vehicle I generally don't have it long afterward.
 

ALRUI

Well-Known Member
First Name
Arnold
Joined
May 18, 2018
Messages
411
Reaction score
147
Location
Murphy, NC
Vehicle(s)
2018 JLU Sahara, 2003 F150 S-Crew FX4, Others
OP
OP

Fsttanks

Well-Known Member
First Name
Tony
Joined
Jul 15, 2020
Messages
358
Reaction score
719
Location
Palm Springs Ca.
Vehicle(s)
2013 JKU / 2014 JK / 2020 JLUR
Update: 11/23

Dealerships called and WAS able to duplicate the problems. Believe it or not....that’s a relief!!

There is a service bulletin on similar issues. Which indicates these events are happening more frequently then is widely known. They performed that work and then found another issue which is requiring some “parts” to be replaced? The “parts” have been ordered.

Jeep Cares contacted me this morning too and said they are working to expedite the shipping of the required parts.

Looks like I will not have the final analysis until much later this week, which sounds suspiciously like Fri or the following Mon.
 

Kyanche

Well-Known Member
Joined
Jun 17, 2019
Messages
898
Reaction score
758
Location
California
Vehicle(s)
2020 Wrangler Unlimited Rubicon
So many damn computers in everything these days, but you'd think they'd at least have some kind of "by-pass" to the ABS block to allow the brake to work manually for precisely this kind of situation?
Computer engineer checking in. There's nothing wrong with using electronics, if they are well designed. The stuff in the JL Wrangler is not well designed. If it were well designed, the OP's scenario (and several others I've read about on the forum) would have never happened. In any safety critical system, there should be basic operation that always works no matter what. Even with a dirty ground, a sketchy power source, and other problems presenting themselves.

Honestly I bet if they had used "good old fashioned" mechanicals for everything, they would've used cheap plastic parts everywhere and it'd all break anyway.

Edit: Sigh. I don't want to sound like I hate Jeep or anything. I really like my Jeep. I like Chrysler stuff in general. From what I've seen, other companies make fairly glitchy software too. But The Jeep's electrical system is kinda ridiculous even for a car lol.
 

Danielos2

Member
First Name
Daniel
Joined
Nov 12, 2020
Messages
15
Reaction score
4
Location
Pahrump NV
Vehicle(s)
2021 JL Rubicon 4-door Sting-Grey
This is a STRONG WARNING to all Jeep JL owners!
3C3EE3B8-D2DA-486D-A813-4B3E154E5553.jpeg


The following is a short summarization of the event, some details have been left out and will be discussed with Jeep before I add them.

This weekend while taking a short family trip in our five month old 2020 Jeep JLUR we had TWO COMPLETE computer failures both without ANY warning.

The first was at a busy intersection the engine shut down and ALL the instruments and infotainment system went crazy included the SOS which started sending alerts that could not be stopped. I had NO ability to activate the hazards lights to warn other vehicles behind me or any ability to restart the engine. Twice we were almost rear ended so when it was safe enough I had my family exit to safety. My Jeep remained immobile in the intersection for almost 10 mins. At which point the computer system reset and I was able to move the Jeep to a safe location. After the incident there were no engine warning light of any kind and all the system were back to work as normal.

Thinking this was a one off glitch we continued on our trip. Well that was a huge mistake. Not much more then 10 min later while driving at freeway speeds there was another COMPLETE computer failure and total loss of ALL vehicle control. The steering all but froze up, engine was sputtering and loosing power worst the brakes were NOT working! All this on top of the other instruments going crazy. I managed with some effort to muscle the steering wheel enough to get the Jeep over to the extremely small “emergency lane” but then had NO brakes to stop with and our speed at this time was around 50mph. I was literally standing on the brake pedal and it was having almost no effect. I ended up having to use the “E” brake to stop our Jeep!

Once stopped, again NO “hazard lights” could be engaged and NOTHING worked! So now we were half in and half out of the traffic lanes. I carry flares and being this had just happen a few minutes early I was thinking about them so I deployed them to warn traffic and hopefully not get rear ended by a high speed passerby.

15 or so minutes later the computer system once again reset? I was then able to move the Jeep off the freeway. This time the “check engine” light was on. Seeing this I though REALLY NO F’N KIDDING.

Needless to say Jeep had a call from me and I have filed a report with the NTSB. Had either one of these incident occurred just a short time early as we had driven through a high speed (70mph) section of winding mountain roads I would not have been able to steer or brake sufficiently enough to have avoided a major crash. Fortunately I am a trained EVOC driver with decades of high speed and off-road skills to draw from. Had my wife or son or anyone with far less experience “behind the wheel” been driving when the last incident happen there is no way they could have safety made it off to the side of the road. Hell I was shaking and almost S**T my pants. I have had failure of steering and brakes before while on the job in other vehicles, but NEVER all the major systems at the same time let alone while at 70mph.

In more then 35 years of drive both personally and as a professional I have never been scared of driving a vehicle until today. I will never trust my JLUR again until Jeep can 100% in writing guarantee me this will NEVER happen again!!!

I don’t think the majority of JL owner actually realizes just how much of their Jeep is controlled solely by the one computer with no backup and that they have no real control over their vehicles except which the computer grants them. So be aware if your computer fails you are just along for the ride. And it’s a scary one!!!

P.S. Yes I am aware there have been other threads on similar topics. But none state the real danger involved. The Jeep was towed to my local dealerships where it will sit until ?. It is not a battery issue as both show full charges and voltage.

Your thoughts and constructive input are welcome.

EDIT NOTE:
1) This JLUR is a standard 3.6 with automatic transmission.
2) The ESS was turned off via the dash off button in both incidents. Always turn it off when I start the Jeep.
3) The tires are 315/70/17 BFG AT2.
4) NO computer “chip” mods were done.
5) The infotainment system is the Alpine with 8.4 screen.

Wow, that is so odd, like the movies you see when a hacker takes control of the car!! Happy you are all safe, my only thought or question is...where in the world are you that they have winding, curving mountain roads that are 70mph, I mean that itself is as bad as the foul computer in the jeep, good grief. I am waiting for my 2021 rubicon, will take this story to heart, thank you.
 
Advertisement

Stinger Off-Road
 
Advertisement
Top