Auto stop and ignition issue

[Buster6670]

Hoping someone can give some insight on this issue with my 2020 Gladiator…
1. A few months ago, my auto stop quit working, but I never got an aux battery warning light on the dash. No big deal.
2. Shortly after, I started getting key fob not detected and have to use the fob to push the ignition button to start.

I changed the battery in my fobs, but problem still persists. At first I assumed that both were related to the aux battery, but also read somewhere that there is a relay that controls both ignition and auto stop. Been searching the web for more on this but can’t find the original info I saw or any other info on these two problems being connected.

Any help is appreciated.

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[Mr._Bill]

How old are the two batteries in your truck?

If more than three years old, replace them both.

 

[Buster6670]

Almost 4 years, but if that is the issue, shouldn’t I be getting a dashboard warning?

 

[BalancedPete]

It's the batteries! Just went through this myself. Eventually, your jeep will start failing to even start at all. If you're especially lucky, when your at a busy intersection and your jeep does its shut down thing, it will not fire back up so you can drive off. You'll then have to have it towed.

When this happened the first time, the dealership said they checked both batteries and did a full load test, everything came out fine. A months later, same issue. I had both batteries changed out, and haven't had any issues. It's been 4 months now.

Good luck!!

 

[Mr._Bill]

Almost 4 years, but if that is the issue, shouldn’t I be getting a dashboard warning?

No. You get a notice when the Aux battery fails the startup test. At that point, you are in the get stranded and odd behavior zone. Your only warning is the Aux Switches and ESS unavailable messages. The average lifespan of batteries in the JT is about three years. If it is driven enough to keep the batteries charged, or if they are kept on a battery maintainer, they will last longer.

 

[mdh67]

Just went through this. Got the ESS not working message, but no trouble with the key fob. Radio issues, central locking issues on exit, and Aux switch issues.
Changed both batteries, all problems resolved. The swap was not difficult, 45 minutes.
Going to deploy some form of battery maintainer that does not involve opening the hood each day.

 

[Jay di]

I had the same problem, I brought it in to the dealership and they did an software update and corrected the problem.

 

[ColoradoCantu]

It most your likely your Aux battery, I just went through this and the only warning I got was Stop/Start not ready. Everything was fine and then at a red light, it stalled and would start but nothing else worked and I was left stranded. I suggest you learn the procedure for bypassing the Aux battery if you decide to wait until it kills your electronics and your left stranded on vacation in hot as hell Tx.

 

[Lunentucker]

I had the same problem, I brought it in to the dealership and they did an software update and corrected the problem.

Do you have details on that on your customer's copy or in your Jeep dashboard online?
TSB number?

 

[Lunentucker]

You can find the service manuals online here.
https://drive.google.com/drive/folders/1ilMr6vi0kt8wqsXmwt2CFDqqAMvyujzp?usp=sharing

There's a sticky at the top of the Maintenance forum.

 

[Buster6670]

Auxiliary battery changed this morning. Both problems still persist.
Main battery tested fine.

 

[Buster6670]

Update...next time I went to start her up, it detected the keyfob. However, the auto stop is still not working. No warning lights on the dashboard still.

 

[JTGuy]

Once in a while I hook up a trickle charger and it takes several hours to top them off. I think it helps make the batteries last longer.

 

[sharpsicle]

Main battery tested fine.

How was it tested? Often places that test for you will say they "passed" but in reality it still needs replacement. Not all tests are done the same (or correctly), and the battery health threshold these days isn't the same as it was a decade or so ago.

If you're at 4 years on the original battery, I would replace it.

 

[Mr._Bill]

Auxiliary battery changed this morning. Both problems still persist.
Main battery tested fine.

Both batteries should be replaced at the same time, especially at that age. They should both be fully charged before installation.

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