[SOLVED] JLU Completely dead in traffic / dash freakout

[jantman]

.


Don't go with an Aux 12..

For -- Aux battery replacement:

DieHard Platinum AGM Battery, BCI Group Size 400, 200 CCA
Part # AUX14-1

Super Start Platinum Auxiliary Battery Group Size 400
Part #AUX14

Braille (Part# B14115) I5Ah 360CCA
Tests from factory at 483 Crank Amps. Wt. 11.5 lbs.
https://www.jlwranglerforums.com/fo...-way-pull-the-fender-flare.56807/post-1911638

Too late on that one; the AUX12 is purchased, charged, and in the vehicle. Yeah, I know what the right part number is. I called a dozen places and nobody has one. They all tell me they just have the AUX12. Their websites all say the same thing, and most of the chain auto parts stores don't even have AUX14's available for order around here.

This is my daily driver and only vehicle, and this is a week that I just can't be without it. I guess we'll see.

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[jantman]

The Jeep is, as far as I can tell, back to normal!

I charged both new batteries and put them in, and left the cable that had been on N3 attached to N4. Started right up, everything seemed fine *except* the 8" UConnect system in the dash; that looked completely different from how it should and was missing XM, a bunch of the apps, backup camera, heated seats, etc. Drove the 12 miles to the dealer to pick up a new fuse and then asked at service about the UConnect BS. Sure enough, after the 12 mile drive, everything in the dash seems back to where it used to be. I also had the check engine MIL lit up, but that cleared after another 15-mile-ish drive cycle.

Per the folks in service, after battery replacement it takes a ~20 mile drive cycle for the UConnect stuff to return to normal and 40-60 miles for the MIL to clear.

So... as far as I can tell, all is well. I'm going to leave the old fuse in for now and keep it with the #3 cable in the #4 slot. Partially because I don't have time to pull the fuse array again yet, and partially because I'd rather not swap the one that I just bought in, if this might happen again.

Oh, and good news, maybe thanks to the PSAs from folks like @Rhinebeck01 ... when I went to pick up my fuse array the woman at the parts desk warned me that there were two very similar parts and there's often confusion about which one is right. I told her that I pulled the part and got the number off of it, and she was very relieved.

 

[jantman]

Now that I changed the thread topic to "[SOLVED]" I guess there's 50/50 odds the brand new batteries will be dead in a week...

 

[jantman]

Just wanted to update, I've put about 500 miles on since I put the new batteries in a month ago. Just after putting them in, after ESS at a red light, I got a check engine light and a bunch of voltage-related codes (P0562 - Powertrain - System Voltage Low, P1DB1 - Powertrain (2 instances), and U1428 - Network (2 instances)). I cleared the codes and have been disabling ESS at the beginning of (almost... when I remember...) every drive. In the few hundred miles since that, all has been well. My plan is to wait until I hit 34,750 and then start leaving ESS on again, and see how it does over the following ~250 miles.

 

[Jephson]

I experienced these same issues with my 2019 Sport that had JUST gone out of warranty - catastrophic failure while driving and had to engage the manual release to push it off the busy tow lane road I was on. After lots of research and changing out both batteries, I ran across this from @jantman. Switched the N3 to the N4 and it's working with no malfunction lights. I'll order the new Mopar Z Case Fuse Array as a permanent fix and see what happens next, but at least it's drivable.

 

[Jebiruph]

I did a write up here. https://www.jlwranglerforums.com/fo...on-and-ess-n3-fuse-warning.66247/post-1548290

 

[Jephson]

@jimcoffey62, do what @Jebiruph says in his thread. Also, at , it will tell you how to replace the Mopar Z Fuse Array.

 

[jantman]

Sorry, was away from the computer for the weekend.

Yeah, I went by those other threads and the YouTube video. Just a couple of notes:

1. After removing all of the nuts and wires on mine, it was still pretty well stuck in there; there's some sort of clip on the bottom. A pair of bent hooks (like O ring pullers, dental picks, or just heavy wire with a 90-degree bend in the end) work perfectly. Just slide one under each end of the fuse array and pull straight up. I now keep two of these in my jeep tool kit.
2. If you really want to test the fuse and confirm that it's dead, pull it from the vehicle and use a multimeter set to resistance/ohms mode. Put one probe on the N3 metal tab and the other on the common metal bar on the other side. A reading of OL / off the scale / INFinite / etc. indicates an open circuit, i.e. the fuse is blown. Any actual resistance reading indicates that the fuse is good (or that you're touching both sides of it ). This assembly looks fancy and new on the outside, but it's just a bunch of normal fuses molded into a fancy case.
3. I bought a replacement, but I haven't swapped it out yet, I just swapped the wire. If this fuse blowing is a known issue, then as far as I'm concerned each assembly contains TWO 150A fuses and I fully intend to use both of them
4. Just personal feeling, but unlike the guy in the YouTube video, I would NOT use an impact wrench on these. The studs that the fuse array mounts to are just pressed into relatively thin sheet metal terminal strips; they're electrical connectors, not mechanical connectors, and they're not intended to handle more than modest hand torque.

 

[Jephson]

Alright next question on this issue @jantman and others - as much as I dislike the ESS, even though everything else is normal now, ESS still doesn't appear to work. Any thoughts on what that issue might be?

 

[jantman]

Alright next question on this issue @jantman and others - as much as I dislike the ESS, even though everything else is normal now, ESS still doesn't appear to work. Any thoughts on what that issue might be?

How long has it been? According to the service guys at my dealer, it can take 60 miles or so of drive cycles for everything to go back to normal. I don't have exact numbers written down, but I'm pretty sure that my ESS wasn't working for a while after the replacement either, but after either clearing all the codes or just enough drive time, it started working again.

 

[Jephson]

Got it. I've never been known for my patience. Just completed the N3/N4 swap yesterday, so it's good to know that it doesn't reset immediately. I'll give it some time and see what happens. Thanks!

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