The infamous start/stop aux battery

[Proximo]

Same exact happened to me last week when out of town on vacay. Jumped it. Started right up. Had the same code. Drove it 3 days, nothing……. Pulled the IBS plug 15 minutes. In a day the sevice light went away. All good.

What is the IBS plug?

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[ShadowsPapa]

What is the IBS plug?

This is a picture of the IBS - Intelligent Battery Sensor
There is a connector with two smaller wires on the end of the IBS, shown below as the network connector.
That is network and power to the IBS electronics inside the IBS.
I do an IBS reset if I take things apart and fully charge each battery independently to get things back in synch and starting over again.
It takes a few hours of sitting - with the fob clear away from the Jeep, along with a couple of big button starts, to get the IBS to relearn.

The red arrow in the pic below points to the IBS as it's installed on the crank battery negative post. Ground cables connect to the top of it. The network connector is on the end facing the firewall.

 

[NvrGvUp]

There's no need for a kit of any kind.

You can bypass the aux battery easily by...
1. disconnecting the aux ground at the main ground group
2. wrapping the cable to prevent incidental grounding
3. zip tying it out of the way
4. Removing fuse F42
ESS will still function as normal, but using just the main battery.
You can disable it using a third party device like Tazer or Auto Start Stop Eliminator, or you can learn to press the button on the dash. You can lay down the outermost hood switch plunger and it will not function, but the light will still come one on the dash.

Here's the video I made on the bypass procedure. Ignore the part about it saying that ESS will be disabled. That was wrong.
I did this last July, and there have been zero issues.




You can do a full delete, but that's more involved.

Excellent reply to the original thread! Good Diagram!

 

[NvrGvUp]

There's no need for a kit of any kind.

You can bypass the aux battery easily by...
1. disconnecting the aux ground at the main ground group
2. wrapping the cable to prevent incidental grounding
3. zip tying it out of the way
4. Removing fuse F42
ESS will still function as normal, but using just the main battery.
You can disable it using a third party device like Tazer or Auto Start Stop Eliminator, or you can learn to press the button on the dash. You can lay down the outermost hood switch plunger and it will not function, but the light will still come one on the dash.

Here's the video I made on the bypass procedure. Ignore the part about it saying that ESS will be disabled. That was wrong.
I did this last July, and there have been zero issues.




You can do a full delete, but that's more involved.

Your video did not show the jumper wire (seen in the diagram) between N3 and N1. Did you add the jumper? It appears to complete the 12v+ circuit from the Aux battery (which has been removed). Without the jumper, and with the fuse removed, it seems that the ESS system will be completely disabled. Without the jumper what issues might occur?

 

[ShadowsPapa]

Your video did not show the jumper wire (seen in the diagram) between N3 and N1. Did you add the jumper? It appears to complete the 12v+ circuit from the Aux battery (which has been removed). Without the jumper, and with the fuse removed, it seems that the ESS system will be completely disabled. Without the jumper what issues might occur?

No jumper is needed with his method. None.

 

[wbnjr]

There's no need for a kit of any kind.

You can bypass the aux battery easily by...
1. disconnecting the aux ground at the main ground group
2. wrapping the cable to prevent incidental grounding
3. zip tying it out of the way
4. Removing fuse F42
ESS will still function as normal, but using just the main battery.
You can disable it using a third party device like Tazer or Auto Start Stop Eliminator, or you can learn to press the button on the dash. You can lay down the outermost hood switch plunger and it will not function, but the light will still come one on the dash.

Here's the video I made on the bypass procedure. Ignore the part about it saying that ESS will be disabled. That was wrong.
I did this last July, and there have been zero issues.




You can do a full delete, but that's more involved.

I have disconnected the aux and pulled fuse. I am still getting the A! Error on start up screen. Will this finally go away after computer is refreshed( or whatever you call it) thx

 

[KevinC]

I have disconnected the aux and pulled fuse. I am still getting the A! Error on start up screen. Will this finally go away after computer is refreshed( or whatever you call it) thx

First you need to make sure you disconnected the correct ground cable. Jeep changed it up on us back in 2022 I believe.

 

[Lost1wing]

First you need to make sure you disconnected the correct ground cable. Jeep changed it up on us back in 2022 I believe.

If he tied back the wrong cable from the main negative, everything would be dark. Most likely scenario is that his main battery is at a low enough state that it has failed the start up test. Then, when the computer sees the same voltage, it thinks both batteries are at a low charge status. His best bet would be to put f42 back in, charge both batteries independently and check the battery voltages 30 minutes after charging, while still isolated from each other. Disconnect the IBS connector while charging the batteries and plug it back in after everything is reconnected. There are no short cuts. Once he figures out his problem and it is working correctly, he can pull f42 and tie back the aux neg.

 

[Trollboogie]

FYI.... One of the hood pins went bad on my 21 and I was getting the A! error . One of the two pins works with the start stop system. I don't remember which one.

 

[DanW]

There's no need for a kit of any kind.

You can bypass the aux battery easily by...
1. disconnecting the aux ground at the main ground group
2. wrapping the cable to prevent incidental grounding
3. zip tying it out of the way
4. Removing fuse F42
ESS will still function as normal, but using just the main battery.
You can disable it using a third party device like Tazer or Auto Start Stop Eliminator, or you can learn to press the button on the dash. You can lay down the outermost hood switch plunger and it will not function, but the light will still come one on the dash.

Here's the video I made on the bypass procedure. Ignore the part about it saying that ESS will be disabled. That was wrong.
I did this last July, and there have been zero issues.




You can do a full delete, but that's more involved.

If you do that, you can get rid of the Aux battery completely, right? I'd love to get rid of the dead weight, along with disabling it.

 

[Mr._Bill]

If you do that, you can get rid of the Aux battery completely, right? I'd love to get rid of the dead weight, along with disabling it.

The Aux Battery is not a significant amount of weight.

Removing the Aux Battery does not disable anything. ESS is always on and active, even with only one battery.

 

[DanW]

The Aux Battery is not a significant amount of weight.

Removing the Aux Battery does not disable anything. ESS is always on and active, even with only one battery.

No, but why bother carrying dead weight? Makes no sense if it has no use and is not needed. And a little here and there adds up.

 

[Lunentucker]

If you do that, you can get rid of the Aux battery completely, right? I'd love to get rid of the dead weight, along with disabling it.

A few here have done the full removal, but it's a bit more involved.

 

[2021JeepGladiator]

FYI.... One of the hood pins went bad on my 21 and I was getting the A! error . One of the two pins works with the start stop system. I don't remember which one.

Which are these pins?

 

[ShadowsPapa]

Which are these pins?

They are the two SWITCHES at the driver side front. Hood switches, not pins.
Two of them and they work together.

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