ESS not working (2020 Wrangler Unlimited Rubicon)

[GaryA]

Although I usually press the button to turn off the ESS, I've noticed that lately the engine is not turning off when stopped. Today I toggled through the info screen and got to the auto shut off area I first saw "engine warming up" as a reason there was no ESS. A bit later I looked and saw "battery charging". Note:power connection I have nothing new plugged into a lighter connection and with only 12K miles and a year old, can't imagine the battery is going.

Anyone with a clue what happened?

Thanks

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[steverj64]

I've got 2018 3.6 JLUR and have noticed the same thing. It starts and runs fine, I've just had a system update done at the dealer. Could it be the aux. battery is going bad?

 

[mwilk012]

Battery is probably bad.

 

[Rockstar08]

I have read also if your ess battery is constantly charging most likely because the battery is bad you will also see your gas mileage drop significantly. So have you noticed your MPG’s dropping also?

 

[johnbyron]

How often do you drive? If you drive it just a couple of times per week or just on short trips, it's normal for ESS not to be ready.

 

[GaryA]

I've got 2018 3.6 JLUR and have noticed the same thing. It starts and runs fine, I've just had a system update done at the dealer. Could it be the aux. battery is going bad?

Possibly, where is this AUX battery located and is it easily replaceable?

 

[GaryA]

How often do you drive? If you drive it just a couple of times per week or just on short trips, it's normal for ESS not to be ready.

Good point, I don't drive daily but when I do it's 20+ miles, enough for the battery to charge

 

[whiterubicon]

I noticed that after I started driving less, the ESS started working less frequently. I thought the auxiliary battery was going bad, but after a weekend where I drove a bit more, it started to work like normal again.

 

[Chupacabra]

Mine has stopped working too. The first time I put a battery tender on it overnight and it worked fine for about 3 weeks. But the last week or so it's not working again. It just says "Stop/Start Not Ready", nothing about the battery or anything. I've been on some steady highway cruises and the voltage reads around 14.2-14.3 now. When ESS was working it was more like 13.9-14.0

I suspect one or both of my batteries is going out too, and probably the PITA to replace smaller one.

 

[johnbyron]

I noticed that after I started driving less, the ESS started working less frequently. I thought the auxiliary battery was going bad, but after a weekend where I drove a bit more, it started to work like normal again.

Same here

 

[steverj64]

With 37's, 4.88's and a lead foot I get about 14.5mpg. Less withAC. Electrically however I've added a winch. Ran the power through a 500 amp relay with a 400 amp fuse on the main battery.( Relay for winch and compressor are both powered by AUX 1 SWITCH on dash.) Both batteries are the same age. Jeep manufactured May, 2018. I purchased March 2019. I hate the ESS so I wonder if I can just leave the dead, hard to reach AUX. and replace the main just for peace of mind.

 

[steverj64]

I have read also if your ess battery is constantly charging most likely because the battery is bad you will also see your gas mileage drop significantly. So have you noticed your MPG’s dropping also?

guess I did the quote thing wrong. See my last message hahahaha

 

[steverj64]

Possibly, where is this AUX battery located and is it easily replaceable?

The AUX battery is located under the main, and apparrently you gotta remove the fender to get to it. seems easier to me just to figure out how to live without it, and the ESS.

 

[johnbyron]

I previously thought the ESS not engaging was due to me not driving the car enough. This weekend I drove it for hours, but it still says "battery charging", despite the total voltage of the two batteries being over 12.6V. The alternator keeps charging at 14.4V. I am wondering if the Aux battery is dead or if there is an issue with the voltage sensor. I booked an appointment for the dealer to have a look next week.

 

[Rhinebeck01]

I previously thought the ESS not engaging was due to me not driving the car enough. This weekend I drove it for hours, but it still says "battery charging", despite the total voltage of the two batteries being over 12.6V. The alternator keeps charging at 14.4V. I am wondering if the Aux battery is dead or if there is an issue with the voltage sensor. I booked an appointment for the dealer to have a look next week.

@johnbyron

DO, politely ask the Service Writer to show you / share with you the two different "load tests" results. Printed...... and each print out will report on one battery.. So, you are looking for 2 printouts..
Don't ask, don't get.... 8-(

I usually ask to speak to the Service Manager versus asking the Service Writer that more often then not, will not take care of your wants lets say...

IF you do not ask to see these print outs you cannot be positive the Tech did the 2 load tests that he/she should be doing... Some/probably most Techs.... will just test out one battery when they should be load testing both.

More often then not the Aux battery is the issue.... but the Main has been impacted very negatively as it is hooked up in parallel with the frucked up Aux.

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