3.6L ESS Battery Cable Diagram

[jebiruph]

I've noticed there's not as much ESS battery information here as on the Wrangler forum. So here's my diagram of the ESS battery cabling, based on the JL, but I'm pretty sure the JT is the same.

Edit 1/22/2022 - updated diagram

There's more information here https://www.jlwranglerforums.com/forum/threads/3-6l-ess-dual-battery-consolidated-information.25377/

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[Jawjadawg]

Thanks Jerry I'm having a helluva time finding info on this system and whenever I search it mainly comes up with promos for alternative systems. Its not like this is a standard battery with two posts and normal cables. If anyone else has any other resources or strings they would recommend it would be greatly appreciated.

 

[ShadowsPapa]

Images and diagrams for that system are all over the place here, including pictures of the real parts, information on how the negative cables changed for the 2021 model year and later, and much more.

Much of it is standard, it's just that there's a second smaller battery connected in parallel so when you believe you have killed the electric system by taking the negative cables off the IBS on the main battery - it's still hot because of the other parallel battery.

But there's countless threads on this around here, with dozens of pictures and diagrams.

 

[LouisvEarlleJT]

Hey @ShadowsPapa , if someone were doing an alternator swap which ground would cut off everything? It looks like everything converges on the main battery negative terminal per the diagram above, so unhooking that is what you need to do, is that correct?

(I thought this question would be a good addition to this sticky)

 

[ShadowsPapa]

Hey @ShadowsPapa , if someone were doing an alternator swap which ground would cut off everything? It looks like everything converges on the main battery negative terminal per the diagram above, so unhooking that is what you need to do, is that correct?

(I thought this question would be a good addition to this sticky)

You need to take the two cables off the top of the IBS and take the two apart.

To make sure you have both batteries "ungrounded" you remove the pair from the top of the IBS, and then take those two apart from each other and keep them from touching ground.

The cable marked 2020 is the ground for the aux battery in 2020 model year, and the cable marked 2021+ is the aux cable ground for 2021 and later.
To be safe - assume both should not touch ground or anything else when disconnected from each other then you don't have to worry about which is the aux ground and which grounds the main to the chassis.
(Arrow points to IBS - now and then people coming in new to modern vehicles and the terminology. IBS = intelligent battery sensor. It sends information to the system as far as amps in, amps out, battery temperature and so on.)

Example of IBS data -

Intelligent Battery Sensor (IBS) Data 3:
Intelligent Battery Sensor Lifetime Charge Received: 2861.75 A/h
Intelligent Battery Sensor Lifetime Charge Released: 2765.75 A/h
Intelligent Battery Sensor Voltage Before LIN Wakeup: 7.58 V
Intelligent Battery Sensor Wake Up Reason: Not defined
Intelligent Battery Sensor (IBS) Data 4:
Intelligent Battery Sensor Calculated Battery Resistance: 2.00 Ohm
Intelligent Battery Sensor Resistance at 100 % SOC and 25 Deg.C: 1.74 Ohm
Intelligent Battery Sensor Accumulated Time Since Last Reset: 28 sec

 

[Banned]

If I'm looking at the diagram correctly, a person could delete aux battery, N1 to aux pos. cable, aux pos. to PCR cable, PCR, PCR to N3 cable, and aux ground cable?

 

[jebiruph]

If I'm looking at the diagram correctly, a person could delete aux battery, N1 to aux pos. cable, aux pos. to PCR cable, PCR, PCR to N3 cable, and aux ground cable?

Some do report removing those cables, but you still have to provide battery power to N1 for the system electronics.

 

[ShadowsPapa]

He's got years of reading to catch up on............

It's been done by quite a few, others simply remove the battery and pull the F42 and leave stuff in place - in case of warranty work or trade or whatever. I can't see a compelling reason to remove it all, personally, and it makes it easy to convert back for warranty or trade.
N1 must be powered in some way - take the battery out, cover/insulate the terminal connections, pull the fuse, done.

There's countless tales and explanations of all of this all over the place here, where some have done it either way.
If removing ALL of the extra cables, you must jump N1 to a power source, such as perhaps N3 (it's fused at least) or whatever.

 

[Hootbro]

If I'm looking at the diagram correctly, a person could delete aux battery, N1 to aux pos. cable, aux pos. to PCR cable, PCR, PCR to N3 cable, and aux ground cable?

That is the full aux battery delete. Still need to fab and install a jumper between N1 and N3.

https://www.jeepgladiatorforum.com/...ning-no-politics.23705/page-1570#post-1132146

Only thing I did different than in the post I linked is that I took the negative cable end off the AUX battery and ran it to the same firewall ground as the main battery. All the other wires in the diagram I removed.

 

[SkyKing]

He's got years of reading to catch up on............

It's been done by quite a few, others simply remove the battery and pull the F42 and leave stuff in place - in case of warranty work or trade or whatever. I can't see a compelling reason to remove it all, personally, and it makes it easy to convert back for warranty or trade.
N1 must be powered in some way - take the battery out, cover/insulate the terminal connections, pull the fuse, done.

There's countless tales and explanations of all of this all over the place here, where some have done it either way.
If removing ALL of the extra cables, you must jump N1 to a power source, such as perhaps N3 (it's fused at least) or whatever.

Just to be clear in my mind.
The auxiliary battery has two positive cables running to it. They are tied together at the aux batt positive connector. One cable comes directly from the main battery connector/distribution connector. The second cable then runs up to the PCM Fuse Array terminal N3?

If F42 is pulled and the aux battery positive cables are still connected to each other (wrapped and protected from inadvertently shorting out), N1 and N3 are stilled powered, the Jeep Start/Stop system is disabled.

Will a Start/Stop warning still post on the instrument cluster?

 

[ShadowsPapa]

Just to be clear in my mind.
The auxiliary battery has two positive cables running to it. They are tied together at the aux batt positive connector. One cable comes directly from the main battery connector/distribution connector. The second cable then runs up to the PCM Fuse Array terminal N3?

If F42 is pulled and the aux battery positive cables are still connected to each other (wrapped and protected from inadvertently shorting out), N1 and N3 are stilled powered, the Jeep Start/Stop system is disabled.

Will a Start/Stop warning still post on the instrument cluster?

None of this disables ESS. ESS will still function, or try to.
The ONLY way to disable ESS is to get in the truck, start it and push the ESS off button
or
Tazer
or
One of the ess disable devices sold through a forum sponsor or another source.

All any of this does is take the aux battery out of the equation.
ESS will function, or if it sees a problem, it will try to and show an error on the cluster display.

All pulling F42 does is prevent the opening of the PCR to check aux battery voltage - if that can't open then the system sees the main battery voltage and ignores the fact that the aux battery is gone (well, sort of - ESS seems to keep working for a half dozen times before deciding there's a problem)

On my second JT now - all electric systems still in place and plan on keeping it that way.

Main battery is charged through N7 to N2 and out to main
Aux battery is charged through N7 to N3 out through PCR to aux battery positive.
"System electronics" powered by aux battery to post N1
(that's an over-simplification as I've determined that some things do actually still pull from the main battery during ESS stops by using a volt meter on each battery while the truck shuts down at a stop. There's obviously still loads on the main/crank battery during an ESS stop event.)

Pulling N42 simply means PCR can't open for the quick aux battery check during the big button start cycle (TIP start)

 

[SkyKing]

Great information.

So, since I physically removed the aux battery, taped up the aux battery positive terminals, I am “assuming” the two cables are attached to a bracket together because I didn’t inspect closely… tied up the cables and put the cover back on… could my jeep be dead because the two positive aux cables are in fact not connected together as I assumed?

BTW
my aux battery showed 13 volts when I bench tested it…. 36 month battery. This is the second aux battery in my 2020 Gladiator.
I”ll replace it with a new Mopar and restore the system.

My start/stop system troubles started last year when I saw a message to “update” the system. I hit okay and drove the jeep to work. After work I drove home and put it in the garage. The next morning the jeep wouldn’t start.
Boom… start stop inop.
I charged the battery and just kept putting it off until I got a check engine light a few days ago, I started to monitor the battery voltage while the engine was running and shut off.
Voltage fluctuated from 12.2 volts to 14.1 volts. Battery voltage was 12.5 with everything shut off.
I pulled F42 fuse, voltage stabilized so I decided to remove/delete aux battery. And here I am with a completely dark instrument panel Jeep Gladiator.

 

[dayusmc]

So if you were deleting the Aux battery and wiring completely, do you need to hook up N3?
I know N1 and N2 are needed, but I believe in the eTorque models there is a sold bus bas connecting N1 to E2, I will take a picture today of my wife's eTorque JLU.
So I guess what I am asking is if we delete the Aux battery, what is N3 needed for?
Hopefully I was able to ask what I am thinking correctly, I sometimes have a hard time communicating what I am thinking...

 

[ShadowsPapa]

So if you were deleting the Aux battery and wiring completely, do you need to hook up N3?
I know N1 and N2 are needed, but I believe in the eTorque models there is a sold bus bas connecting N1 to E2, I will take a picture today of my wife's eTorque JLU.
So I guess what I am asking is if we delete the Aux battery, what is N3 needed for?
Hopefully I was able to ask what I am thinking correctly, I sometimes have a hard time communicating what I am thinking...

You must feed N1 - IMO, that's best done from N3.
If you did remove all extraneous wiring after pulling the aux battery, there's nothing feeding N1.
N3 would be free and unused and since it's at least fused (way high for that need, but still, it's a fuse) - to me, N3 is the logical place to tie N1 to.

Etorque is a very very different system. i'd not even begin to compare or figure that what works for the 3.6 ESS system would also convert over to the etorque system. Different voltages and so on.
I WISH these were etorque! Honestly, I'd really like one of these in the etorque system.

Hopefully I was able to ask what I am thinking correctly, I sometimes have a hard time communicating what I am thinking...

Live with diagnosed severe ADHD where you head is swimming 10,000 mph but the output can only come out at 10 mph and you trip over your own thinking and it's like someone is sitting on the remote to your brain, all buttons pressed at once.

So - I get it!
I know it - using it - communicating it, is where a meat clever cut things apart.

 

[dayusmc]

You must feed N1 - IMO, that's best done from N3.
If you did remove all extraneous wiring after pulling the aux battery, there's nothing feeding N1.
N3 would be free and unused and since it's at least fused (way high for that need, but still, it's a fuse) - to me, N3 is the logical place to tie N1 to.

Etorque is a very very different system. i'd not even begin to compare or figure that what works for the 3.6 ESS system would also convert over to the etorque system. Different voltages and so on.
I WISH these were etorque! Honestly, I'd really like one of these in the etorque system.


Live with diagnosed severe ADHD where you head is swimming 10,000 mph but the output can only come out at 10 mph and you trip over your own thinking and it's like someone is sitting on the remote to your brain, all buttons pressed at once.

So - I get it!
I know it - using it - communicating it, is where a meat clever cut things apart.

Thank you. The reason I was asking is instead of making a jumper from N3 to N1, I was think of just getting the same fuse block as my wife's eTorque, I am not worried about the cost, just want it as clean as possible.
Another question, I know we can pull that fuse so the computer isn't doing that test. Could we also just unplug the wire from the PCR valve, or would that throw a code?

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