New Aux battery, ESS light now on, can't clear

[Sixt7gt350]

For a few weeks, no ESS stops, but no light on.
Yesterday, didn't remote start. (no messages, just didn't start) So I got in, wouldn't start from inside, either.
I assumed the Aux battery had gone bad, draining the main down while sitting, replaced it.
A couple trips of "ESS not available, charging."

This morning on the way to Menards, "battery charging" finally went off, "ESS ready"
At Menards yard gate, getting inspected, ESS stops like "normal" Foot off brake, attempts restart, everything flashes, radio blasts an instant of static, ESS light comes on, "service system" (put in P, started fine)
Can't get light to clear with OBD reader. OBD shows battery voltage 14.5. Remote start works fine, normal start works fine.
Never had light when Aux battery was NG, won't clear now.

November 2019 purchase, so a little over 5 years in both batteries.

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[Sixt7gt350]

Also, pulled fuse 42 after light came on, no effect

 

[Andy29847]

For a few weeks, no ESS stops, but no light on.
Yesterday, didn't remote start. (no messages, just didn't start) So I got in, wouldn't start from inside, either.
I assumed the Aux battery had gone bad, draining the main down while sitting, replaced it.
A couple trips of "ESS not available, charging."

This morning on the way to Menards, "battery charging" finally went off, "ESS ready"
At Menards yard gate, getting inspected, ESS stops like "normal" Foot off brake, attempts restart, everything flashes, radio blasts an instant of static, ESS light comes on, "service system" (put in P, started fine)
Can't get light to clear with OBD reader. OBD shows battery voltage 14.5. Remote start works fine, normal start works fine.
Never had light when Aux battery was NG, won't clear now.

November 2019 purchase, so a little over 5 years in both batteries.

"I assumed aux battery had gone bad" - poor assumption

"OBD shows battery voltage 14.5" - this is charging voltage. To measure true battery voltage, the batteries have to be separated, you have to wait until the surface change bleeds off, and then you measure each battery individually. One of the issues with the Jeep system is that a battery can meet industry standards for condition (12.4v = half-life) and not support ESS.

If it was me, I would change the main battery. I'd buy a Walmart premium (Eversmart) H7 battery. Leave everything disconnected for 15 minutes when you change the battery, especially the IBS. Hopefully, the system will reset when you install the new main. Sometimes it takes a little time for all of the systems to return to normal operations.

Be cautious with battery cables while doing the work. Some of the cables have power from the aux battery. Use something to insulate the ends when not connected to the main battery.

My answer was to delete the aux battery and install a device to bypass the stop start. here is my link: https://www.jeepgladiatorforum.com/...ery-with-a-premium-h7-group-94-battery.76866/

 

[Bully4]

Wild guess-did you change both batteries? The main doesn't appear to have been replaced. The 14.5 might just be a "surface charge". You might not have enough capacity to start the engine when all the accessories are running during a ESS stop. Also, probably would be best to fully charge both and re-check.

 

[Sixt7gt350]

Main was fully offline charged while replacing the aux. (Fender liner removal, remove, drive to town and back, reinstall)
No starting issues or warning lights for the few trips between the new Aux battery and this morning's restart failure.

Given 5+ years out of both and the typical reported life of 3 years, I'm going to replace the main today with EverStart H7.

Stop-start is a worthless and troublesome addition to modern vehicles.

 

[Lost1wing]

You might read up on IBS and how to reset. Pulling f42 does not fix anything. It prevents the PCR from opening. The computer will only see the main and Aux battery value connected in parallel. It fools the computer if one of your batteries is in poor condition.

Continue your plan to replace your main battery. Do not assume that you new main will be fully charged when you buy it. Do not assume that your currently installed new Aux is charged, because it is not. Be careful with cable ends. The fuse array does not like shorts to ground.

 

[Sixt7gt350]

You might read up on IBS and how to reset. Pulling f42 does not fix anything. It prevents the PCR from opening. The computer will only see the main and Aux battery value connected in parallel. It fools the computer if one of your batteries is in poor condition.

Continue your plan to replace your main battery. Do not assume that you new main will be fully charged when you buy it. Do not assume that your currently installed new Aux is charged, because it is not. Be careful with cable ends. The fuse array does not like shorts to ground.

Leaving both battery terminals disconnected for 30 minutes before connecting the new H7 didn't help, I can say that.

Put F42 back in.

 

[Lost1wing]

Charge both batteries and reset the IBS. If you pull both terminals off of the main, the Aux is still powered. Separate the cables at the main neg. One is your Aux neg, and the other is the main ground going to your fender. Pull the connector off of the IBS sensor at your main neg post. Charge both batteries until your AGM battery charger says they are charged. Do this one at a time. Reconnect the fully charged battery connections at the main negative. Reinstall the IBS connector.

 

[Lost1wing]

It is sad to say that a few do it yourself guys sometime rush into things not realizing that there is a second battery or they don't understand how the cables connect the batteries together. I see that you knew about the Aux and were careful with your cable ends. The fuse array will need to be disassembled and tested if you are still having faults with two new charged batteries andcthe IBS reset.

 

[Lost1wing]

Leaving both battery terminals disconnected for 30 minutes before connecting the new H7 didn't help, I can say that.

Put F42 back in.

I don't know how it was disconnected, but if you pulled the terminals off of the main battery post, the Aux was still powering the vehicle and most likely drained. When you reinstalled those terminals back on the main post, you would still have a problem, being that the now drained aux is dragging down the main. Reinstalling f42 now let the PCR open. The computer saw the drained aux. The work around this would have been to leave the negative cable from the Aux tied back( not connected) and pull f42. When you turn on the ignition now, the main is no longer being drained from the discharged aux and the computer thinks your aux and main are healthy. (Assuming your main is fully charged) Your computer needs to see the charge state of the batteries. Restting the IBS will let the compter start a fresh relearn cycle. That is why the batteries need to start fully charged. You would not be doing yourself any good cheating the system by resetting the IBS with weak or partially charged batteries.

 

[Pakdoc]

I recently purchased another new battery for my 2020 bc the old but "good" battery I swap as a spare in my Chevy truck with no issue....has issues for the Jeep. Seems the Jeeps eat batteries as I am now on my 3rd main battery and second Aux and OMG they are getting expensive!

 

[Lost1wing]

I'm on my 5th year of the OEM batteries. I really think it comes down to how the battery is maintained and if it sat for a long period on the dealer lot. If the truck sat at the factory lot for 6 months waiting for a backordered part, the chance of that battery being drained to a point that it needed to be jumped off is not unreasonable. Due to Covid and supply chain issues, we saw that with our Gladiators. I picked up my Gladiator just before the lock downs. However, my batteries were far from perfect. I lived with "battery charging" for a while. I knew something was wrong and decided to look into it. I could have buried my head in the sand and just waited for a no start or multiple lights and warnings to display on the dash. The biggest help was from a post from ShadowsPapa. That post inspired me to dig deaper and start troubleshooting Hell, that was my job before retirement.

I didn't have an AGM charger so at first I used my lead acid charger. It worked for the most part, but then I read more about AGM batteries and charging. I though it was best to add a new tool to my inventory. As it turns out, I have purchased 3 additional pieces of equipment that have AGM batteries.

Since I have charged both batteries with an AGM charger and reset the IBS, my ESS indication of " Ready" comes on immediately after the engine is warm . I do maintain my batteries with a NOCO charger( permanently installed) every couple of weeks. I hardly drive the JT as it is not my daily driver.

 

[Sixt7gt350]

I don't know how it was disconnected, but if you pulled the terminals off of the main battery post, the Aux was still powering the vehicle and most likely drained. When you reinstalled those terminals back on the main post, you would still have a problem, being that the now drained aux is dragging down the main. Reinstalling f42 now let the PCR open. The computer saw the drained aux. The work around this would have been to leave the negative cable from the Aux tied back( not connected) and pull f42. When you turn on the ignition now, the main is no longer being drained from the discharged aux and the computer thinks your aux and main are healthy. (Assuming your main is fully charged) Your computer needs to see the charge state of the batteries. Restting the IBS will let the compter start a fresh relearn cycle. That is why the batteries need to start fully charged. You would not be doing yourself any good cheating the system by resetting the IBS with weak or partially charged batteries.

Disconnected both batteries completely, fully charged each battery with a Schumacher charger.
IBS was completely disconnected and removed from vehicle for over 4 hours.

Today after work was (at least 8-hours between) start number 6.
The ESS light came on, along with the "service stop/start system" notice.

 

[Lost1wing]

Disconnected both batteries completely, fully charged each battery with a Schumacher charger.
IBS was completely disconnected and removed from vehicle for over 4 hours.

Today after work was (at least 8-hours between) start number 6.
The ESS light came on, along with the "service stop/start system" notice.

What were the battery voltage readings after charging, would be my first question? My next question would be, did you verify that your Fuse array is good? If all that is good, I would check for a battery drain.

 

[Andy29847]

Disconnected both batteries completely, fully charged each battery with a Schumacher charger.
IBS was completely disconnected and removed from vehicle for over 4 hours.

Today after work was (at least 8-hours between) start number 6.
The ESS light came on, along with the "service stop/start system" notice.

Both new batteries?

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