New ESS "issue"?

[alphawolff]

Let me preface by saying that I don't care that the ESS isn't working, and have done zero troubleshooting with no intention of really digging into it, but am curious to see if anyone might have experienced the same "issue".

About 7 or 8 months ago I noticed that the ESS on my 18 JLUR wasn't working. The only dash warning is the "ESS not ready. Battery charging" in the message center. No other warning lights are lit up. Charging system is consistently in the 13.8 to 14.5 range. No other issues with electrical system, no starting/cranking issues. Both batteries are about 2 years old. Maybe 3. I forget exactly.

The general consensus seems to be that my aux battery is toast and should have killed my main battery and left me (or even worse - my wife) stranded somewhere by now, but it has not. I'd also expect that I'd have a warning light or two in addition to the message center notification.

So I guess what I'm getting at is, is it common for ESS to quit with no dash lights illuminated, no other electrical issues and still be up and running months later?

The ESS requires an SOC over 65% to function. Lower than this and you will get a "Battery charging" message in the EVIC. The vehicle will continue to start and function fine until the batteries begin to fail completely. It will be sudden with no warning. You will go out one morning and it won't start. You only get a S/S warning light if the aux battery outright fails the voltage load test upon first crank. It takes awhile to get to the point. You may also find it stalls out at a red light blowing the z-case fuse, which is very common.

Replace both batteries before you are indeed left stranded.

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[jaymz]

The ESS requires an SOC over 65% to function. Lower than this and you will get a "Battery charging" message in the EVIC. The vehicle will continue to start and function fine until the batteries begin to fail completely. It will be sudden with no warning. You will go out one morning and it won't start. You only get a S/S warning light if the aux battery outright fails the voltage load test upon first crank. It takes awhile to get to the point. You may also find it stalls out at a red light blowing the z-case fuse, which is very common.

Replace both batteries before you are indeed left stranded.

That's the kinda detail I was looking for. Not at all interested in replacing the perfectly good main battery at the moment, so I guess I'll be bypassing the aux battery this weekend. Not a fan of the "fail without warning" situation.

 

[alphawolff]

That's the kinda detail I was looking for. Not at all interested in replacing the perfectly good main battery at the moment, so I guess I'll be bypassing the aux battery this weekend. Not a fan of the "fail without warning" situation.

The SoC is actually only read for the primary battery. It is a very real possibility your primary is actually the one failing and the aux is fine. It's why we always recommend to replace both. Sometimes the aux fails and drains the main, and sometimes the main fails and the aux is totally fine.

If you do bypass it, make sure you fully re-charge your primary and keep a close eye on it. Let it sit for a day then go out the next and check the battery voltage. If its cold resting voltage after a day is under ~11.9 I'd strongly suggest replacing it.

 

[andy29847]

The ESS requires an SOC over 65% to function. Lower than this and you will get a "Battery charging" message in the EVIC. The vehicle will continue to start and function fine until the batteries begin to fail completely. It will be sudden with no warning. You will go out one morning and it won't start. You only get a S/S warning light if the aux battery outright fails the voltage load test upon first crank. It takes awhile to get to the point. You may also find it stalls out at a red light blowing the z-case fuse, which is very common.

Replace both batteries before you are indeed left stranded.

The way I would have said it is that ESS stops working when the batteries get near the 12.4 level. The dash voltmeter is not much help in determining which battery is causing your problem. The 2 batteries are hooked together at all times except for a stop start event. There supposedly is a brief separation of the 2 batteries on start up for a system test, but the system does not deliver any useful information from that test to the driver except for stop/start not working messages. Voltage readings made from the dash voltmeter are made with system loads present and therefore the readings will be less than the actual state of charge.

I have disabled the stop/start on both of my Jeeps. I have one Jeep with a single Walmart Premium AGM battery (4 year warranty). The other has new Mopar batteries that were replace dunder warranty just before my Jeep hit the 3 years/36,000 miles line in the sand. I'll go with the Mopar batteries for a couple of years and then switch to a single battery, hopefully before any battery trouble causes problems.

Peace of mind at last! Replaced main battery with a premium H7/Group 94 battery | Jeep Gladiator (JT) News, Forum, Community - JeepGladiatorForum.com

 

[MauiSteve]

21 JLR stick
ESS has never worked.
I’ll be doing my batteries soon because at 3 years + mine always start to go, like it or not, in any vehicle I own.

 

[Reinen]

That's the kinda detail I was looking for. Not at all interested in replacing the perfectly good main battery at the moment, so I guess I'll be bypassing the aux battery this weekend. Not a fan of the "fail without warning" situation.

That's not going to work out well for you and will cost more money in the long run. Both in batteries and/or getting stranded at a random time. So many people make this mistake and complain about chronic battery issues, blaming ESS and Aux.

First of all, you do not have a perfectly good Main. It's at best close to failing. The batteries work as a linked pair. You cannot have one fail without the other being close behind. That's just how parallel linked batteries work, they will always fail together.

You say you're not a fan of "fail without warning" but you just received that warning (ESS not engaging w/ Battery Charging) and you're not heeding that warning. Both your Main and Aux are in bad shape. It doesn't matter which one is worse, the other is right on its tail.

Replace Main and Aux at the same time. That will retain the battery failure warning you just enjoyed and fend it off for the longest period of time. Since both batteries are new they won't stress each other and will last their full lifespan which will be about 3 years, give or take a bit.

 

[Linda z.]

Let me preface by saying that I don't care that the ESS isn't working, and have done zero troubleshooting with no intention of really digging into it, but am curious to see if anyone might have experienced the same "issue".

About 7 or 8 months ago I noticed that the ESS on my 18 JLUR wasn't working. The only dash warning is the "ESS not ready. Battery charging" in the message center. No other warning lights are lit up. Charging system is consistently in the 13.8 to 14.5 range. No other issues with electrical system, no starting/cranking issues. Both batteries are about 2 years old. Maybe 3. I forget exactly.

The general consensus seems to be that my aux battery is toast and should have killed my main battery and left me (or even worse - my wife) stranded somewhere by now, but it has not. I'd also expect that I'd have a warning light or two in addition to the message center notification.

So I guess what I'm getting at is, is it common for ESS to quit with no dash lights illuminated, no other electrical issues and still be up and running months later?

Mine says start stop not working cabin heating cooling. I don't know what that means

 

[double0762]

Let me preface by saying that I don't care that the ESS isn't working, and have done zero troubleshooting with no intention of really digging into it, but am curious to see if anyone might have experienced the same "issue".

About 7 or 8 months ago I noticed that the ESS on my 18 JLUR wasn't working. The only dash warning is the "ESS not ready. Battery charging" in the message center. No other warning lights are lit up. Charging system is consistently in the 13.8 to 14.5 range. No other issues with electrical system, no starting/cranking issues. Both batteries are about 2 years old. Maybe 3. I forget exactly.

The general consensus seems to be that my aux battery is toast and should have killed my main battery and left me (or even worse - my wife) stranded somewhere by now, but it has not. I'd also expect that I'd have a warning light or two in addition to the message center notification.

So I guess what I'm getting at is, is it common for ESS to quit with no dash lights illuminated, no other electrical issues and still be up and running months later?

My 2020 has given me the same message for a year now. ESS not available battery charging. Only problem I have is when I start my jeep I sometimes don't have AC right away. AC button light and heated mirror button come on and won't turn off for about 2 minutes and I have no blower fan for that time period. After that it works fine. I'm sure it's a little hint my jeep is telling me to change batteries as they are original. I will disable ESS though.

 

[There’sOnlyOne]

Mine says start stop not working cabin heating cooling. I don't know what that means

Normal operation of system. Let's you know that the ESS won't engage until your HVAC system reaches the temp you have selected. If it's warm outside and you are cooling the cab down you don't want the system to stop the engine, which interrupts the cooling process. Same goes for heating. The engine will continue to run normally operating the HVAC normally to reach the temp you have selected. Once the cabin is at the selected temp then when you stop the ESS will engage.

 

[Yawnie'sPapa]

I would strongly recommend replacing the AUX battery
Possibly replacing BOTH batteries soon
My 2022 JLURD did exactly same thing. Brought to dealer, load tested and MAIN battery defective/replaced. Aux drained the Main battery
Best wishes

Are you SURE it was the aux that went first? That's what a lot of Jeep people say - because that's what they read, but over in another forum with Jeeps - several have had the MAIN battery go first, and the aux was just fine. They replaced the main and then later the aux battery.
It's internet lore that the aux goes first and ruins the main battery, but if it was the case of one battery going and taking out the other, then those of us who have had tractors and other equipment with multiple batteries would have always had to replace all of the batteries instead of just the one bad battery. Too often one is on the edge of going, the other goes, and then the aux is blamed for taking out the main. I see about 50/50 in another forum. People are starting to admit that they actually keep track and test/check things, and the main has gone first.
Think of the 4xe - those owners complain of the 12v battery going bad after anywhere from a few months to a couple of years. There's no aux battery to take it out - it simply went bad because Jeep original batteries suck.
We had a Grand Cherokee where both batteries tested bad - oddly, the main battery seemed to be the bigger problem. It got to where it wouldn't hold a charge no matter what. So in our case - it was the main battery that went, dealer replaced both.


As to ESS not working - there are over 30 criteria monitored for ESS. That's things from CAT temperatures to torque applied to the steering wheel (even if it's straight if you have pressure on it, the ESS won't function), and a whole host of other things. It's pretty deep reading on what makes ESS work or not work, and how the batteries are tested during startup and so on.
Funny thing - Jeep people say "the aux battery runs the electronics" - but no one has traced the PDC circuits to my knowledge........... I spent some time on that and found that some of the modules are powered by the main battery. In fact, during an ESS stop event when I monitored the voltage of each battery independently using two VOMs, I found the voltage of the main battery went down almost in lockstep with the voltage of the aux battery. That means the load is actually rather split during an ESS stop - some electronics powered by the main battery.

 

[NewbJLUOwner]

Are you SURE it was the aux that went first? That's what a lot of Jeep people say - because that's what they read, but over in another forum with Jeeps - several have had the MAIN battery go first, and the aux was just fine. They replaced the main and then later the aux battery.
It's internet lore that the aux goes first and ruins the main battery, but if it was the case of one battery going and taking out the other, then those of us who have had tractors and other equipment with multiple batteries would have always had to replace all of the batteries instead of just the one bad battery. Too often one is on the edge of going, the other goes, and then the aux is blamed for taking out the main. I see about 50/50 in another forum. People are starting to admit that they actually keep track and test/check things, and the main has gone first.
Think of the 4xe - those owners complain of the 12v battery going bad after anywhere from a few months to a couple of years. There's no aux battery to take it out - it simply went bad because Jeep original batteries suck.
We had a Grand Cherokee where both batteries tested bad - oddly, the main battery seemed to be the bigger problem. It got to where it wouldn't hold a charge no matter what. So in our case - it was the main battery that went, dealer replaced both.


As to ESS not working - there are over 30 criteria monitored for ESS. That's things from CAT temperatures to torque applied to the steering wheel (even if it's straight if you have pressure on it, the ESS won't function), and a whole host of other things. It's pretty deep reading on what makes ESS work or not work, and how the batteries are tested during startup and so on.
Funny thing - Jeep people say "the aux battery runs the electronics" - but no one has traced the PDC circuits to my knowledge........... I spent some time on that and found that some of the modules are powered by the main battery. In fact, during an ESS stop event when I monitored the voltage of each battery independently using two VOMs, I found the voltage of the main battery went down almost in lockstep with the voltage of the aux battery. That means the load is actually rather split during an ESS stop - some electronics powered by the main battery.

Yes, I'm sure 1 or BOTH batteries are defective

 

[Renostever]

I have the same issue on a 2019 I recently purchased used with 23k miles. I’ve owned it for 3 months and 2k miles with no warning lights. I did disconnect the negative terminal of the aux battery and remove fuse #42. I plan to pull the aux battery all together soon. Happily I don’t have to defeat the ESS every time I start the Jeep.

 

[Reinen]

My 2020 has given me the same message for a year now. ESS not available battery charging. Only problem I have is when I start my jeep I sometimes don't have AC right away. AC button light and heated mirror button come on and won't turn off for about 2 minutes and I have no blower fan for that time period. After that it works fine. I'm sure it's a little hint my jeep is telling me to change batteries as they are original. I will disable ESS though.

A little hint?
That's about as big a hint as you can get without complete failure. The IBS (Intelligent Battery Sensor) is telling the ECM (Electronic Control Module) to shut down non-critical electrical systems to ensure the Jeep keeps running in the several minutes after starting.
You're on the very precipice of getting stranded.

If you do disable ESS you will be disabling the first battery failure warning. ESS is always the first non-critical system to get shut down due to poor batteries. Frankly, it's the most useful aspect of ESS.

 

[double0762]

A little hint?
That's about as big a hint as you can get without complete failure. The IBS (Intelligent Battery Sensor) is telling the ECM (Electronic Control Module) to shut down non-critical electrical systems to ensure the Jeep keeps running in the several minutes after starting.
You're on the very precipice of getting stranded.

If you do disable ESS you will be disabling the first battery failure warning. ESS is always the first non-critical system to get shut down due to poor batteries. Frankly, it's the most useful aspect of ESS.

Ok then, I guess I know what I'm going this wknd. For mine and my wife's jeep

 

[Mrlimelight]

Let me preface by saying that I don't care that the ESS isn't working, and have done zero troubleshooting with no intention of really digging into it, but am curious to see if anyone might have experienced the same "issue".

About 7 or 8 months ago I noticed that the ESS on my 18 JLUR wasn't working. The only dash warning is the "ESS not ready. Battery charging" in the message center. No other warning lights are lit up. Charging system is consistently in the 13.8 to 14.5 range. No other issues with electrical system, no starting/cranking issues. Both batteries are about 2 years old. Maybe 3. I forget exactly.

The general consensus seems to be that my aux battery is toast and should have killed my main battery and left me (or even worse - my wife) stranded somewhere by now, but it has not. I'd also expect that I'd have a warning light or two in addition to the message center notification.

So I guess what I'm getting at is, is it common for ESS to quit with no dash lights illuminated, no other electrical issues and still be up and running months later?

My ESS only worked a couple times in the 2 1/2 years I have had my 2022 Rubicon. In May my wife stopped to eat and it would not start. No trouble lights. Called Jeep they sent tow truck he jumped it and told me to get a battery. New main battery still would not start. Being a 6 speed we rolled it off and drove it home. Dealer said the clutch pedal switch was only code. Said they changed it and no more issues. But the next time I drove it the ESS worked.

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