2018 JLU Aux temporarily unavailable battery charging

Punjabi New Yorker

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Yes I do have 3.6. I completely agree I could do without having to turn it off every time I crank it as well! Still haven’t heard back from the dealership but I’m hoping it’s just a simple fix.
If they do not respond on time, Try to disconnect and reconnect the batteries yourself as a last resort. Wait 30 seconds after you disconnect to reconnect. See if that resolves anything. That was what I had done once and it helped. Will be better however if the dealership does this themselves since they could have erred when they were working on your Jeep.

Here is a guide on doing a disconnect since the newer Wranglers have two batteries (main one and an aux one for ESS): https://www.jlwranglerforums.com/forum/threads/to-kill-12v-power-to-the-jl-jlu.6244/
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Dkretden

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Last I heard they said it was a bad fuse... kept it overnight. I haven’t picked it up yet to see what they did.
I’m gonna bet you that they also ran the “battery check’ that they did on mine. It takes a long time (they say) and it needs to be kept overnight. Hopefully it was a simple fix for you and you can get Jeeping again tonight!
 

Tar Heel Wrangler

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Had my ESS do the same. They replaced the aux battery, twice. Ended up being a bad relay. They replaced the fuse box. It's been fine since then.
 

Punjabi New Yorker

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Had my ESS do the same. They replaced the aux battery, twice. Ended up being a bad relay. They replaced the fuse box. It's been fine since then.
I disconnected the battery and then reconnected after 30 seconds. That took care of the issue for me. (fingers crossed).
 
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Crystalee

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Had my ESS do the same. They replaced the aux battery, twice. Ended up being a bad relay. They replaced the fuse box. It's been fine since then.
They replaced my aux battery and fuse as well!
 
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Crystalee

Crystalee

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Dealer replaced my aux battery & the fuse as well. I’m hoping this isn’t something that will need to be replaced every couple of years. Thank you to everyone that responded!
 

Spank

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Mine is starting to do this, too, but I think it's my main battery. It's only showing 12.0v when the engine isn't running and it's been struggling to start lately. Mopar batteries are notorious for eating shit after 2-3 years and since I have a 2018, the timing sounds about right. Hopefully it's as simple as that.
 

wibornz

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Mine will do this after it sits for a couple days with the fridge running in the back. After running for about a minute. I am good to go.
 

Spank

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I replaced my main battery, didn't bother with fuses, relays, or the aux battery, and everything is fine now. The "Aux Temporarily Unavailable" message and the "Service Electronic Throttle Control" message that would randomly appear for a brief moment when starting the Jeep are gone. I also notice my door locks don't actuate as sluggishly as they used to, which was something that started a few months ago.
 
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