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ESS problems need input.

Steph1

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Greetings guys,

first discussion I start, yes I've searched and read tons on here before posting.

Jeep JLU Sahara 3.6 2018 with 10000 miles. Basic warranty ended in May 2021.

In early 2019, my ESS stopped working and I constantly had the ''ESS battery charging'' message. Dealer replaced both batteries and all was well until Covid arrived and Jeep stayed parked a lot.

Last spring (2021) I noticed that the ESS wasn't working again and I had the same ''Battery charging message''. So I took numerous Country road trips with all electricals off, hoping the ESS would charge, but it never worked again.

So early this week, I decided to check to see if I could find what is wrong and got online to find a few conversations on this here forum regarding ESS and hard PDC fuses and even watched a video with Brandon Haneline about the subject.

First thing I noticed, was that N2 and N3 cables were reversed (the numbers are engraved on the end of the cables). It went ( N1-N3-N2-N4......) So I thought to myself that's it!!!, those idiots didn't bother connecting things right.... (After all, these are the same guys that put 7.5 quarts of oil last oil change and ''fixed my back glass so poorly that it exploded when I tried to use the defrost for the first time and then denied it was their fault) so I'm gonna correct that myself.

So I followed David Haneline's video to the T, disconnected both negatives and even wrapped them up separately to avoid any troubles and proceeded with switching N2 and N3 to put them in numerical order like they should be.

PROBLEM (or is it a problem?): When I reconnected the negatives to the main battery post, I experienced sparks and heard a few clicking sounds like a solenoid would make. While it worried me, cause on David's video, there were no such sparks, I continued to put things back together and went for a ride.

OBSERVATION: While all I previously had was the ''Ess not ready battery charging'' message, I suddenly had proper information (or maybe I had them before but never noticed them)... ''ESS not ready, transmission not in a forward gear'' or something like that, then ''ESS not ready, engine not warm enough'' and then '' ESS in Battery protection mode'' what does ''PROTECTION MODE'' mean??? this I never saw before I am certain.

So I messaged David Haneline with the information above and all he replied was that I blew a 100amp fuse in the PDC.

-Is that a fact ???
-Anyway to test that ???
-Which fuse are we talking about ???
-Is it something that is urgent to replace???
-Will I end-up stranded if I don't fix this now ??? ( I have a 2 hour trip to take this coming week-end...)
-If I blew a fuse merely by reconnecting the negative posts, will it blow again when I reconnect the battery after replacing the whole PDC unit??
- Any possibility that the dealer purposely switched the cables as part of the fix when they replaced both batteries, like a TSB or something ???

Everything else seems to work perfectly except for ESS. I have a multi-meter but not sure where and how to check if the fuses are good

Lots of questions I know,

Thanks for any help,

Steph
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Steph1

Steph1

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@Steph1

A little hard following what all you did or did not do and what all you have going on.... BUT...... if in fact the fuse in the High Amp Fuse Array is blow, then the alternator is not going to be able to charge the ESS battery.... and thus the ESS stays depleted..

I assume your 2018 JL has had the TSB applied to it that allows the Jeep to start on the second attempt to start it... and that you are also seeing a little warning light on the dash...

If your JL has the factory tow package it uses a different fuse array then the JL without the factory tow package... Read through this thread: https://www.jlwranglerforums.com/forum/threads/internal-fuses-in-the-pdc.15456/

Unless you have both batteries load tested, you do not know if either or both are currently problematic. Good chance one or both batteries are problematic now/ again..

Here is how to change the fuse array...

Thanks, I'll look up that link. That's the video I watched and learned from before checking and realizing that the N2 and N3 switches had been inverted. Yes I do have the ''factory '' tow package, but it was installed at the dealer, not at the factory. Would that explain why they switched N2 and N3 ?
 
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Steph1

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@Steph1

Here is how to kill ALL 12v power:
Jeep power disconnect.png
Thanks, I only removed nut 2 ( secondary battery) and isolated it, then nut 3 (main negative cable) and isolated it Like Brandon Haneline does in his video. Never touched nut number 1.

It is while reconnecting the main negative cable that it sparked a little.
 
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Steph1

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@Steph1

Your JL will have the 68368853AA Mopar Z Case Fuse Array as your tow bar, etc. was not installed at the factory/ you do NOT have the factory tow package and what comes with it.

Read this thread: https://www.jlwranglerforums.com/forum/threads/help-with-n-terminal-connections.74322/

Thanks Rhinebeck01, just finished the reading. I like that I am learning along the way.

Regarding my N2 and N3 that I found inverted, I am wondering if:

1- that could have been done on purpose due to the ''Mopar'' tow package, which doesn't make much sense to me....

2- Simple mistake by the tech when the dealer changed both my batteries in Spring 2019. But what I question, is that ESS worked fine for almost a year with the N2 and N3 in the wrong position???

3- Could there be a memo to dealer techs to do that N2-N3 switch ?

Was I smart to perform the switch and put them in their numerical order ?

I plan on going for a ride tonight to see if I end-up stranded or get any dash light.
 
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Steph1

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So you're saying that the dealer messed up these cables at this point,



despite the cables not only being labelled, but possessing key tooth patterns to prevent them from being switched? Wow!

Steph: regardless of how this plays out (i.e. what is at fault) given the infrequency of your use, I'd seriously consider buying a trickle charger if you park in a place with access to shore power (i.e. A/C).

Put the trickle charger's connections on the main battery. As both batteries are connected on the 3.6L in parallel at all times but an instant during normal startup, and during ESS events, placing your cables on the main battery's terminals will charge both batteries when the vehicle is parked and at rest.

Many owners find such trickle charging necessary to get ESS to work.

There may be more to your problem than this, but the trickle charging is a good idea for infrequent use 3.6L JLs regardless.

Now, a bit of a history lesson. The 2018 3.6L JLs were designed such that if the ESS battery lacked adequate power the vehicle would not even attempt a crank. You could have a fully charged main battery---and the fact of the matter is that said crank is actually, if attempted, normally powered by both batteries....

...the point is, with a dead ESS battery you weren't going anywhere--the crank would not even be attempted.

In 2019 and beyond model years the engine crank logic changed such that if the ESS battery lacked adequate power, a SECOND (and beyond) attempt to crank would switch over to the main battery and attempt the crank solely from there.

If successful, your rig would turn ESS off (turning the ESS off light on) and all future cranks would be against the main battery only, until the ESS battery was charged or replaced with one with ample power, and parked 3.6L recranked.

Please note: the power necessary in the ESS battery to engage ESS is a much higher threshold than that to crank the engine.

It's also been reported that a dealer flashing technical service bulletin (TSB) 18-092-19 will get your 2018 3.6L to behave like a 2019 or newer 3.6L as it regards this "either battery" cranking behavior.

As I've tested that describe, I can tell you that I too heard clicks--but had no sparks. I wouldn't jump to any conclusions that your sparks were indicative of problems--though they of course could be.

And while Mr. Haneline could be correct about you blowing one of the high amp fuses under which those misaligned cables reside, what you can do is first see if the trickle charging resolves your issue before replacing the high amp fuse bar--which will have to be replaced in its entirety if any of its fuses are blown---but you will not necessary need an entirely new PDC box (which includes said fuse bar and is much more expensive than the fuse bar alone.)

Steph--it kinda of makes no difference which of the fuses in that bar is/are the 100 amp one. If you blew any of them I would strongly urge at minimum the replacement of the entire fuse bar before any trip. Problems with one or more of the fuses on this part might affect your ability to recharge your batteries, which could most definitely, if the case, end up stranding you.

If you blew a fuse merely by reconnecting the negative posts, then it might blow a new high amp fuse bar if the short that caused the first high amp bar to blow hasn't been resolved. But we are getting ahead of ourselves. We don't know for certain that you blew the existing high amp bar, or that if you did, if replacing it and hooking cables back up with ruin a new one.

I see the dealer's switch of the cables--assuming we're talking about the cables in my linked video--to be a flat out mistake.

Thanks Gee-pah, yes that's exactly what I thought to myself when I noticed the inverted switch, not only are they numbered, but the teeth don't even fit right in there !!!! So anyways, they are back at their respected position.

I'll go for a ride tonight and see how things go.

It is more the BATTERY PROTECTION MODE that I was seeing for the first time that made me think something went wrong.

As for the sparks, they were small very short sparks... it is the noise that followed ''clicking'' that had me wonder, but the more I think of it, I had just given power back to the Jeep, so of course things were getting power again.

To be followed. I wish there was a way to test the PDC with a voltmeter to see if a fuse was blown or not.
 

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Forgetting for a second if some switching of N2 and N3 is indicated, assuming we're talking about these cables, how did the dealer even get them to seat properly short of breaking the teeth on them designed to prevent such things:

Jeep Wrangler JL ESS problems need input. 1626897709075
 
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Steph1

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Forgetting for a second if some switching of N2 and N3 is indicated, assuming we're talking about these cables, how did the dealer even get them to seat properly short of breaking the teeth on them designed to prevent such things:

Jeep Wrangler JL ESS problems need input. 1626897709075
That's them, They were sitting crooked
 

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Thanks Gee-pah, yes that's exactly what I thought to myself when I noticed the inverted switch, not only are they numbered, but the teeth don't even fit right in there !!!! So anyways, they are back at their respected position.

I'll go for a ride tonight and see how things go.

It is more the BATTERY PROTECTION MODE that I was seeing for the first time that made me think something went wrong.

As for the sparks, they were small very short sparks... it is the noise that followed ''clicking'' that had me wonder, but the more I think of it, I had just given power back to the Jeep, so of course things were getting power again.

To be followed. I wish there was a way to test the PDC with a voltmeter to see if a fuse was blown or not.
You've got a multimeter Steph so why not monitor the battery voltages before and after your run.

Here's how to do that:

You CANNOT simply take your meter to the terminals of the main battery. Such a reading will give you a COMPOSITE voltage of both batteries.

If you want to test the voltage of each battery separately here is how that is done.

1) Remove all cables from the negative post of the main battery.
2) Put your tester on the main battery's terminals. Your reading is that of the main battery's voltage.
3) Move your negative tester only to the free dangling cable I just had you detached. That reading is the voltage in your ESS battery. Yes...I know, your positive on the multimeter is still on the main battery. Trust me, it's the ESS battery's voltage.
4) Reattach the cable back to the negative post of the main battery.

Repeat the test after your ride. In fact, pull lots of current in your ride. I want to know that your batteries aren't dropping in voltage and that the alternator is charging them while you travel.
 
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Steph1

Steph1

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You've got a multimeter Steph so why not monitor the battery voltages before and after your run.

Here's how to do that:

You CANNOT simply take your meter to the terminals of the main battery. Such a reading will give you a COMPOSITE voltage of both batteries.

If you want to test the voltage of each battery separately here is how that is done.

1) Remove all cables from the negative post of the main battery.
2) Put your tester on the main battery's terminals. Your reading is that of the main battery's voltage.
3) Move your negative tester only to the free dangling cable I just had you detached. That reading is the voltage in your ESS battery. Yes...I know, your positive on the multimeter is still on the main battery. Trust me, it's the ESS battery's voltage.
4) Reattach the cable back to the negative post of the main battery.
I'll try that, hope I don't get the little sparks again ;)
 

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@Steph1 , since you have the cables connected in the right place now, you should be able determine if the N3 fuse was blown by reading the voltage of the N3 terminal with the engine running. You should see alternator voltage of > 13v. If it's < 12v, it's battery voltage and the fuse is blown.

If the N3 fuse is blown, move that cable to N4. The N4 fuse is rated the same as the N3 fuse and that will restore aux battery charging until the fuses are replaced.

Swapping N2 and N3 essentially swaps the aux battery and the main battery, except the main battery is still connected directly to the starter. I think it's likely that no damage resulted from the cable swap. It probably wouldn't hurt to unplug the IBS connector to reset it just in case it got confused.

Jeep Wrangler JL ESS problems need input. underhood main positive cable change.PNG
 
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Steph1

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@Steph1 , since you have the cables connected in the right place now, you should be able determine if the N3 fuse was blown by reading the voltage of the N3 terminal with the engine running. You should see alternator voltage of > 13v. If it's < 12v, it's battery voltage and the fuse is blown.

If the N3 fuse is blown, move that cable to N4. The N4 fuse is rated the same as the N3 fuse and that will restore aux battery charging until the fuses are replaced.

Swapping N2 and N3 essentially swaps the aux battery and the main battery, except the main battery is still connected directly to the starter. I think it's likely that no damage resulted from the cable swap. It probably wouldn't hurt to unplug the IBS connector to reset it just in case it got confused.

underhood main positive cable change.PNG
Good information,

If this info is worth anything, I haven't had time to dive-in with my multimeter, as her majesty reminded me we were going to the movies last evening ( a promise is a promise) but the cluster voltmeter was showing between 14.1 to 14.5 volts on my ride yesterday with no electricals on other than the daytime driving lights and with the engine not running, the Voltage was 12.8V.

I confirm that everything works perfect except ESS of course and I haven't seen the ''BATTERY PROTECTION MODE'' like the day before, only the '' Stop/Start not ready, battery charging'' message.
 
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Good information,

If this info is worth anything, I haven't had time to dive-in with my multimeter, as her majesty reminded me we were going to the movies last evening ( a promise is a promise) but the cluster voltmeter was showing between 14.1 to 14.5 volts on my ride yesterday with no electricals on other than the daytime driving lights and with the engine not running, the Voltage was 12.8V.

I confirm that everything works perfect except ESS of course and I haven't seen the ''BATTERY PROTECTION MODE'' like the day before, only the '' Stop/Start not ready, battery charging'' message.
There isn't any monitoring of the aux battery voltage or charging status, you'll have to use the volt meter to test the N3 fuse as described above. There is no indication when it gets blown until right before you get stranded.

Jeep Wrangler JL ESS problems need input. underhood N3 fuse power.PNG
 
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Steph1

Steph1

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There isn't any monitoring of the aux battery voltage or charging status, you'll have to use the volt meter to test the N3 fuse as described above. There is no indication when it gets blown until right before you get stranded.

Jeep Wrangler JL ESS problems need input. underhood N3 fuse power.PNG
Alright, just came back from my garage and got the readings with the engine running. My voltmeter with the black pen on the negative and the red on the N3 cable, I got 14.37... for sake of comparison, I tried all other N cables and got the exact same reading. 14.37.

So what does this mean ??
 

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Alright, just came back from my garage and got the readings with the engine running. My voltmeter with the black pen on the negative and the red on the N3 cable, I got 14.37... for sake of comparison, I tried all other N cables and got the exact same reading. 14.37.

So what does this mean ??
That's what it's supposed to be, all the fuses are good.
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