Engine Start Stop not working???

[Gladiator Brad 704]

2020 JT Rubicon 27K miles. Noticed yesterday that the Engine Start Stop is not working. This doesn't bother me at all. Usually I press the button to disable this annoying feature. Just want to make sure that something important is not broken. Voltage displayed on the Off Road Page shows 14.4-14.5. Truck runs fine. The information screen has failed and I am waiting on the part to replace that. I have been waiting since October 18, 2022. Dealer keeps telling me it is in the mail. That is a whole other story don't get me started. Ant ideas?

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[Jeeperjamie]

Plenty of threads on it. You probably either need to drive it and let the small/Aux battery charge or your Big battery is bad. How many miles do you have on it and has it been sitting for a extended period of time. Mine did the same thing and it ended up being a dead cell in my big battery
Don't trust a volt meter or auto part stores, if your not sure take it to the dealership and let them hook it up on the machine. Mine was 13.2 volts and parts store told me the main battery was good so it had to be the aux battery and when I took it to the dealership and they checked it they came back with a dead cell in the main battery. Had it replaced, drive it for 50 miles and the auto start/stop started working again. It had not worked in probably 4 to 6 weeks and the only reason I decided to do something about it was because I went out and my jeep was dead one morning. Hopefully this helps

Nevermind about the miles, just saw you mentioned the mileage.

 

[Jeeperjamie]

https://www.jeepgladiatorforum.com/forum/threads/auto-start-stop-never-ready.66181/

https://www.jeepgladiatorforum.com/forum/threads/auto-stop-start-stopped-working.55217/

https://www.jeepgladiatorforum.com/...age-after-aux-battery-change-what-next.65665/

Here's a few to look through

 

[Commodus]

2020 JT Rubicon 27K miles. Noticed yesterday that the Engine Start Stop is not working. This doesn't bother me at all. Usually I press the button to disable this annoying feature. Just want to make sure that something important is not broken. Voltage displayed on the Off Road Page shows 14.4-14.5. Truck runs fine. The information screen has failed and I am waiting on the part to replace that. I have been waiting since October 18, 2022. Dealer keeps telling me it is in the mail. That is a whole other story don't get me started. Ant ideas?

I found out that if you are running 14.5 all the time one of your batteries is going bad. The charging system is only supposed to charge when the batteries are low or needed to run accessories 13.0 is usually normal

 

[Rockabillyroy]

I found out that if you are running 14.5 all the time one of your batteries is going bad. The charging system is only supposed to charge when the batteries are low or needed to run accessories 13.0 is usually normal

This is why I replaced my batteries. The SS had stopped working and run voltage was always around 14.5.

Now the SS works again and voltage runs at about 13.

 

[ShadowsPapa]

I found out that if you are running 14.5 all the time one of your batteries is going bad. The charging system is only supposed to charge when the batteries are low or needed to run accessories 13.0 is usually normal

It depends. Mine runs 14.9 most of the time when it's cold.
Otherwise it's in the 13s even when the batteries read at just under 12.7
My 2022 hasn't been as low as 13.0 in a very long time and yet all systems are normal and the batteries read almost fully charged much of the time (except when it sits a lot, or short drives, or it's cold)
I've noticed the 2022 runs higher "running voltage" than my 2020 did. I suspect they've changed things.
If the temperatures are below 35-40 your voltages are going to run higher than in the heat of summer.
Using the numbers from my BCM for IBS resistance and calculated battery resistance, at 14.8 volts it's only charging 2.x amps to the battery.

Mine was 13.2 volts and parts store told me the main battery was good

That's why I don't trust parts stores. You can't "test" a battery by the voltage (as far as CCA and capacity) and that high usually means there's a surface charge that needs to be drained before load testing.
Unless they disconnected the ground cables, or you did, they were testing both batteries together anyway. You must disconnect and separate the ground cables from the IBS to test the main battery alone. Then they could test the aux battery as well - if they knew how.

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