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New '18 JGC HA - had it just over a month now. ESS was working fine up until about a week ago and has not kicked in since. EVIC usually throws a couple of reasons as to why ESS is not ready, but the one that always seems to stick and concern me is "battery charging". How could that be on a vehicle this young? Do I need to check my main battery? Or the aux one everybody mentions is in place for the ESS?

I have not been on a trip longer than about 5 miles in the past two weeks...could that have anything to do with it?

Thanks!
 

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mine on my 2017 grand cherokee has that alot also. i do live in a cold winter climate. many times in the summer it doesnt work because of cabin temp. id say in the 13 months ive had it it probably works year round abt 25 percent of the time which is probably as designed. to me thats probably 25 percent too much. would be nice if it never worked.
 

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New '18 JGC HA - had it just over a month now. ESS was working fine up until about a week ago and has not kicked in since. EVIC usually throws a couple of reasons as to why ESS is not ready, but the one that always seems to stick and concern me is "battery charging". How could that be on a vehicle this young? Do I need to check my main battery? Or the aux one everybody mentions is in place for the ESS?

I have not been on a trip longer than about 5 miles in the past two weeks...could that have anything to do with it?

Thanks!
Hi jrcade,

If you decide to visit your Jeep dealership for any further diagnosis, please feel free to send me a message. I'd be happy to make sure we follow up during service.

Kori
Jeep Social Care Specialist
 

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Ugh! I tried to reply to this last night but apparently didn’t hit send.

I had ESS on my 2015 KL and again on my WK2. There are a series of conditions that have to be met in order for it to kick in; one of which is a fully charged battery. If you’re only taking short trips, it might not be enough for the alternator to charge the battery even driving around.

If you can drive around for 30 or so minutes for a day and see if ESS engages that might be a good starting point.

You might check the voltage running across the battery with a voltmeter to see if it’s in range.

If you have a trickle charger maybe you can hook it up overnight and see if the ESS kicks in the next day during your normal drive.

If you normally take such short trips, you may need to invest in A trickle charger to keep your battery charged else face early battery failure.
 

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Had this same problem on my 18 gc two days after i bought it. Ess would never work, always battery charging. 14.7V while accelerating. Small battery was shot. Dealer took 2 days to replace. No charge
 

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I have a 2019 GC Alltitude and live in a place that gets snow and cold weather. My vehivle is not 2 years old and was concerned that my ESS stopped working and a dealer said the aux battery was probably low and I needed to take the vehicle on a long, long drive to get the battery charged up. I didn't think this should be happening this early in ownership.
I found this form and have read all of the submissions posted that deal with the ESS or the batteries. The one thing that seemed to be common was that no one seemed to be really certain how things worked or were wired. Since I wanted to know more about the ESS system I called the service manager at the local Dodge dealer and this is what I found out:
  • According to the parts dept., both the main and aux batteries are conventional, not deep cycle batteries
  • The main and aux batteries are wired in parallel with each other
  • You can connect a battery charger to the battery terminals under the hood but keep in mind that you will be charging 2 batteries, not just the main battery. It’s better to charge the batteries individually.
  • To charge just the aux battery with a battery charger you need to disconnect the wiring from at least one battery terminal (+) before connecting the charger otherwise you will be charging both batteries.
  • The main battery is always used to start the vehicle either normally or when the stop/start is engaged.
  • When current is drawn from the main battery it also comes from the aux battery except when starting the vehicle.
  • If the engine is stopped because of the ESS, the current required to operate the heater/AC blower motor, the radio, the dash electronics, the heated seat and steering wheel, etc. comes from just the aux battery.
  • Because the batteries are wired in parallel, the smaller, aux battery, will need to be charged more often than the larger, main battery during the winter months in colder climates because resistive loads like the heated steering wheel and/or the heated seats are normally being used.
  • Because modern cars use an alternator instead of a generator it takes longer to charge a battery and because the alternator in the Jeep is trying to charge 2 batteries at the same time it takes even longer which translates into a longer amount of driving in order to bring both batteries to full charge.

The following is a list of reasons (taken from the manual) why the Stop/Start system doesn’t work: aux battery voltage too low (voltage below a specific threshold value), battery temperature is too hot or too cold, not enough brake pedal pressure, engine temp is too high, the drive wheels aren’t straight, seat belt not buckled, door is not closed, hood is not shut, vehicle is on a steep grade, cabin (hot/cold) temperature has not been reached, HVAC set to defrost with high blower speed, HVAC set to Max AC, transmission not in a forward gear, transmission in manual mode, vehicle transfer case is in 4LO. I haven’t confirmed that there is a dash message specifying why the ESS won’t work but I do know it doesn’t tell you if the cause is a low aux battery.

I hope some of this info might be helpful to others.
 

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I haven’t confirmed that there is a dash message specifying why the ESS won’t work but I do know it doesn’t tell you if the cause is a low aux battery.

I hope some of this info might be helpful to others.
Thanks for the detailed information.

There is a message that appears if the ESS will not work due to low battery, it showed up on my 2018 HA. It was something like "System Start/Stop not ready. Battery charging". The dealer replaced both batteries under warranty a few months ago and it has been fine ever since.
 

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Thanks for the detailed information.

There is a message that appears if the ESS will not work due to low battery, it showed up on my 2018 HA. It was something like "System Start/Stop not ready. Battery charging". The dealer replaced both batteries under warranty a few months ago and it has been fine ever since.
I am beginning to think it's something other than the battery. I will know for sure tomorrow because I am leaving a trickle charger connected to the small auxiliary battery for 24hrs. If the warning light doesn't disappear when I reconnect the battery I will know it's something else. I never got the message you had, simply "start stop system unavailable, have it serviced". The dealer assumed it was a low charge on the battery.
 

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I do not have the ESS in my earlier WK2. But I spent 3 weeks with my daughter this winter in Pennsylvania without a vehicle, using her 2019 Chrysler Pacifica with ESS in cold weather.

She was befuddled as to why the ESS didn't work so often when she drove. I read up on it in the owner manual, and there is a whole list of parameters that must be met before the system is enabled. Which her making almost all short trips in cold weather, where the engine never reached full operating temp explained exactly why she was rarely seeing the ESS being enabled.

What I also saw, while I drove her ESS vehicle doing errands during that time in cold weather. Two are three days of short trips in cold weather, or just left park for 2 or 3 days, even when the engine reached full operating temp, the ESS would not enable and report the battery charging. Then I made a moderate length trip to the mall, it didn't enable on the way there, but it enabled on the way back. Then several days of short trips in the cold or just sitting and it went back to battery charging again. Made another half hour drive and out to the mall, and ESS went back to enabling again, till another couple of days of short trips in the cold or just sitting.....

I saw it as normal, the ESS only enables when the several parameters are met, to include the engine at full operating temp and the aux battery is a 100% charged. If you're typical driving is like what I described, it may be normal, you need to take your vehicle out for a good 30-40 minute trip to get the aux battery 100% charged.
 

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I do not have the ESS in my earlier WK2. But I spent 3 weeks with my daughter this winter in Pennsylvania without a vehicle, using her 2019 Chrysler Pacifica with ESS in cold weather.

She was befuddled as to why the ESS didn't work so often when she drove. I read up on it in the owner manual, and there is a whole list of parameters that must be met before the system is enabled. Which her making almost all short trips in cold weather, where the engine never reached full operating temp explained exactly why she was rarely seeing the ESS being enabled.

What I also saw, while I drove her ESS vehicle doing errands during that time in cold weather. Two are three days of short trips in cold weather, or just left park for 2 or 3 days, even when the engine reached full operating temp, the ESS would not enable and report the battery charging. Then I made a moderate length trip to the mall, it didn't enable on the way there, but it enabled on the way back. Then several days of short trips in the cold or just sitting and it went back to battery charging again. Made another half hour drive and out to the mall, and ESS went back to enabling again, till another couple of days of short trips in the cold or just sitting.....

I saw it as normal, the ESS only enables when the several parameters are met, to include the engine at full operating temp and the aux battery is a 100% charged. If you're typical driving is like what I described, it may be normal, you need to take your vehicle out for a good 30-40 minute trip to get the aux battery 100% charged.
I tried taking it for a long trip of 80 miles but it didn't make any difference, the warning light remained lit. Hopefully after charging the aux battery separately things will be back to normal today. If not I will have to take it to the dealer because either the battery can't provide the necessary current or there is some other reason. I saw the list of reasons why the ESS won't kick in but I am sure all the conditions are met.
Thanks for the info on the Pacifica.
 

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Mine only started working right again when the dealer replaced both batteries under warranty.

BTW, it also appears to me that it is disabled whenever the climate control is set to Auto. Turning the fan knob up or down a notch will re-enable it.
 

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No problems here, even with local runs. We keep ours on a Battery Tender hooked up to the posts under the hood via an SAE pigtail. This will charge both batteries..
 

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Mine only started working right again when the dealer replaced both batteries under warranty.

BTW, it also appears to me that it is disabled whenever the climate control is set to Auto. Turning the fan knob up or down a notch will re-enable it.
It doesn't look like it's the battery, according to the dealer. He thinks it's a sensor.
When I first took the charger off the aux battery I measure 12.97 volts but when I measured it again an hour later it had dropped to 12.64volts. I asked the dealer if the ESS had a threshold for the battery voltage and he said it was 12.6volts. If the voltage drops below that the system will not work until the battery has been charged to above 12.5volts.
One of the telltale issues is that I don't get a message on the dash saying that the battery needs charging like some of the other members said they had.
 

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What does the dash message say?
 

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When the dealer replaced both batteries in mine they also replaced something called an IBM sensor (Intelligent Battery Monitor?). After that, the ESS started working OK. It made no difference if the climate control was in Auto mode or not.
 

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That's different all right. Mine never did that ... it just said charging. Even when it had been charging steadily for 100+ miles ...
 
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