Changed out AUX battery, no ESS service but also not working.

[Johndd]

OK for starters I don't want ass but I had the service start stop light on constantly and I had heard a bad AUX will eventually kill your main. My bright Idea was to change the aux via the engine bay as I didn't have a jack big enough on me to pull the front tire "don't trust the factory crap jack". Once I got to the battery I could tell it was the OEM which would have been 4 years old. Charged the new one prior to starting all of this and since I had to pull the main I topped that one off as well. It was changed in 2024.

Problem now is..I have no "service start stop" message, but it also doesn't work. Everything appears to work as normal except that. I even took it for a spin etc and the engine never cut off. Again I don't care for ASS but I don't want this to be an issue down the road.

I already checked the fuse for it and it was fine and double checked the plug was in that connects at the battery.

Since this jeep has 2 previous owners, I was wondering if there was something they could have done to disable it. Which would be fine for me but it's more peace of mind knowing it's been disabled.

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[Lost1wing]

Did you reset the IBS? Even disconnecting the batteries long enough could reset the IBS. Could be just relearning the SOC before ESS will be available again. Give it a day or two.

 

[Johndd]

Did you reset the IBS? Even disconnecting the batteries long enough could reset the IBS. Could be just relearning the SOC before ESS will be available again. Give it a day or two.

I was starting to wonder that. Thing is I had both batteries out, I would think that alone would reset the IBS.
Funny thing is when I'm driving it'll say "start/stop Ready". 2 seconds after being at a stop light it says not ready. Hopefully it's just learning. Irony is if it does start working I plan on disabling later lol

 

[Lost1wing]

I was starting to wonder that. Thing is I had both batteries out, I would think that alone would reset the IBS.
Funny thing is when I'm driving it'll say "start/stop Ready". 2 seconds after being at a stop light it says not ready. Hopefully it's just learning. Irony is if it does start working I plan on disabling later lol

Let it go to sleep and when it wakes up, it might feel a little better.

Yes. If you had both batteries disconnected for a while, the IBS should be reset. Now if you connect one battery at a time, one battery could start to discharge as soon as you reconnect it. The main fender ground needs to be the last cable connected. It doesn't matter which end of the cable, it just needs to be last.

 

[jac04]

After an IBS reset, the IBS needs to re-learn the battery SOC (state of charge). It should default to 80% SOC. But the FSM states that it may take some 'cycles' and some features (like the ESS) may not work until it updates. So, even if you immediately get the circled A, give it a cycle or two or three for it to go away.

From the FSM:

 

[Johndd]

After an IBS reset, the IBS needs to re-learn the battery SOC (state of charge). It should default to 80% SOC. But the FSM states that it may take some 'cycles' and some features (like the ESS) may not work until it updates. So, even if you immediately get the circled A, give it a cycle or two or three for it to go away.

I don't have the circle anymore since replacing the battery when I switch to the a.s.s screen it will say things properly like cannot start due to ac cooling or the wheel is turned. When I turn off ac and go to a stop it'll switch from saying ready to not ready. No charging indicator or anything. Hoping it's just a learning phase it's going through

 

[ShadowsPapa]

I don't have the circle anymore since replacing the battery when I switch to the a.s.s screen it will say things properly like cannot start due to ac cooling or the wheel is turned. When I turn off ac and go to a stop it'll switch from saying ready to not ready. No charging indicator or anything. Hoping it's just a learning phase it's going through

A misfire or other condition can do that as well. And no, the misfire doesn't have to trigger the MIL.
I've had personal experience with that happening.

This is from a recent IBS service document -

It generally happens pretty fast. Having reset mine more than once (in two different JTs) - I found that it worked after only half a day of sitting.

 

[Johndd]

A misfire or other condition can do that as well. And no, the misfire doesn't have to trigger the MIL.
I've had personal experience with that happening.

God now you got my mind thinking mechanical failures lol. Are the spark plugs known to go out on these? Only 4 years old and since I'm a jeep newbie im still learning. I had thought a lot of the engine problems were figured out with the pentastars since 2018.

 

[ShadowsPapa]

God now you got my mind thinking mechanical failures lol. Are the spark plugs known to go out on these? Only 4 years old and since I'm a jeep newbie im still learning. I had thought a lot of the engine problems were figured out with the pentastars since 2018.

Normally the spark plugs will last easily over 80,000 miles.
However, they had issues with 2021 model year Grand Cherokee, and I believe it included the Wrangler and Gladiator, where they had some defective spark plugs.
I can't say off the top of my head if that defect showed up right away, or miles later. In our case, it showed up after a few hundred miles and that Grand Cherokee bucked like a horse with a burr under its saddle.

 

[Johndd]

Normally the spark plugs will last easily over 80,000 miles.
However, they had issues with 2021 model year Grand Cherokee, and I believe it included the Wrangler and Gladiator, where they had some defective spark plugs.
I can't say off the top of my head if that defect showed up right away, or miles later. In our case, it showed up after a few hundred miles and that Grand Cherokee bucked like a horse with a burr under its saddle.

Started working 2 weeks ago. Turns out I think I wasn't depressing the brake hard enough lol. Now looking in to that device that turns it off at every ignition. Hundred bucks though is steep for what it is.

 

[ShadowsPapa]

Started working 2 weeks ago. Turns out I think I wasn't depressing the brake hard enough lol. Now looking in to that device that turns it off at every ignition. Hundred bucks though is steep for what it is.

Just develop the habit of pressing the button. You get in and press the brake and another to start it, you have the habit of putting it in gear - likely a process for the sound you want (radio, phone music, whatever) just add pressing that button to your routine and pretty soon you won't be able to put it in gear without pressing the button - it will just feel wrong

 

[double J]

OK for starters I don't want ass but I had the service start stop light on constantly and I had heard a bad AUX will eventually kill your main. My bright Idea was to change the aux via the engine bay as I didn't have a jack big enough on me to pull the front tire "don't trust the factory crap jack". Once I got to the battery I could tell it was the OEM which would have been 4 years old. Charged the new one prior to starting all of this and since I had to pull the main I topped that one off as well. It was changed in 2024.

Problem now is..I have no "service start stop" message, but it also doesn't work. Everything appears to work as normal except that. I even took it for a spin etc and the engine never cut off. Again I don't care for ASS but I don't want this to be an issue down the road.

I already checked the fuse for it and it was fine and double checked the plug was in that connects at the battery.

Since this jeep has 2 previous owners, I was wondering if there was something they could have done to disable it. Which would be fine for me but it's more peace of mind knowing it's been disabled.

For tire rotations I use a jackstand that has a bottle jack built in. I also have a normal floor jack.
https://www.tractorsupply.com/tsc/product/powerbuilt-3-ton-all-in-one-jack-1160455

 

[ShadowsPapa]

My bright Idea was to change the aux via the engine bay as I didn't have a jack big enough on me to pull the front tire "don't trust the factory crap jack".

You don't have to take the tire off.

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