Post Aux Battery Delete Issues

[Caveman]

I deleted the Aux battery in my 2020 Sport S about a month ago following the instructions on this forum while installing a new 94R battery. So I insulated the smaller negative cable, zip-tied it out of the way, and pulled the specified fuse. I charged the new battery fully before installing and left the IBS disconnected for a couple of hours before connecting the fully charged battery. All worked well for the last month, but I didn't do much driving. Today, I drove it about 200 miles and when I pulled off the highway, the AutoStart warning light went on. It stayed on the rest of the drive, but after stopping and restarting, AutoStart seemed to be working as usual. When I checked the Voltmeter, though, it was reading 12.8 while driving at speed, maybe 13.2 at idle. When I got home I put a charger on it, and it was only at 93% of full charge. It took a couple of hours on a 16A charger to reach full charge. Is this normal? I never had the AutoStart warning come on with the original battery setup. I thought I might have somehow left the old Aux battery in the system by hooking up the wrong negative cable, but when I swapped the taped-off negative cable onto the main battery, the truck was completely dead, so I'm pretty sure I have the right negative cable hooked up to the main and the Aux battery is thus not in the loop anymore...

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[Lost1wing]

And f42 is pulled?

 

[Caveman]

Yes, I pulled fuse 42. I'll double check tomorrow to see that I didn't pull the wrong one, just for peace of mind.

 

[jebiruph]

When the AutoStart warning light turns on while you are driving, it's usually related to an engine issue like misfires and not the batteries. Battery failures usually occur when the batteries are under a load and not while the batteries are being charged

 

[kb5zcr]

Did you happen to have the A/C on max during this time, I believe the start/stop is deactivated when running max A/C, although I don't know if it displays that message.

 

[mtudb24]

I'll provide my condensed version of a story of my aux battery failure
I got the dreaded Avenger symbol back in the fall of 2024. Drove it for a month or 2 and no issues and finally jeep died in the driveway at 8 volts on the dash gauge. Tied up the aux battery cable and pulled fuse 42. All was well for a couple months. Then all of a sudden my voltage guage went to 15+ volts while driving and headlights were flickering (LED's) for a week or so. Then every light on the dash went on and noticed the volt meter was over 16V volts. Replaced the main battery with a group 94 battery and did the IBS sensor reset. Had some initial problems as the new group 94 battery was not fully charged from the auto parts store. Once I got i fully charged, I've never had another issue and all is good. This was all around 50K miles and just passed 55K miles with no issues since.

 

[KQL]

OP, you don’t mention what method you’re using to disable AutoStart. You taped off the negative cable and pulled F42. That doesn’t prevent the start stop system from working. If you’re still allowing the start stop to activate, but only with the main battery in the loop, you would get a system warning after something like 6 ESS events. Then after an engine restart, I believe that count restarts. So, are you still allowing the ESS to activate at stops?

 

[Caveman]

I like of like the ESS, so I've just let it continue to activate at all stops. I think I've had more than 6 ESS events since I replaced the battery, but I could be wrong about that. I guess I'll drive it for a while and see what happens. In answer to a previous question, the AC was on, but it was on the Auto setting and the cabin had already been cooled down. Having fully charged the battery and reset the IBS (again, after doing so upon initial install), I hope things operate normally.

 

[Lmtz1633]

I like of like the ESS, so I've just let it continue to activate at all stops. I think I've had more than 6 ESS events since I replaced the battery, but I could be wrong about that. I guess I'll drive it for a while and see what happens. In answer to a previous question, the AC was on, but it was on the Auto setting and the cabin had already been cooled down. Having fully charged the battery and reset the IBS (again, after doing so upon initial install), I hope things operate normally.

I think you’re supposed to disable ESS when deleting aux. I believe the aux is what powers your accessories while on ESS.

 

[DanJT]

When I deleted my aux battery, I grounded the neg wire to the frame and the pos to the Battery, pulled the fuse, and deactivated it ESS with Jscan. no problems or light on the dash! I have yet
to get a 94R battery, but since I'm not having any issues I'll wait till this one craps the bed.

 

[ponyboy3]

When I deleted my aux battery, I grounded the neg wire to the frame and the pos to the Battery, pulled the fuse, and deactivated it ESS with Jscan. no problems or light on the dash! I have yet
to get a 94R battery, but since I'm not having any issues I'll wait till this one craps the bed.

You can deactivate ESS with JScan?!
Everything I read said I need the other tool, could you elaborate please?

 

[DanJT]

You can deactivate ESS with JScan?!
Everything I read said I need the other tool, could you elaborate please?

There is a module where you can activate or deactivate the ESS. At least my JScan did!

 

[Wags1965]

Here are screenshots for JScan under Adaptations

 

[ponyboy3]

Much appreciated @Wags1965

 

[Wags1965]

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