And I should've put this in the wk2 specific forum, but now can't figure out how to delete it and don't want to make more posts which is annoying. My sincere apologies.

 

Here it is for anyone that stumbles onto this post:
(11) Jeep Grand Cherokee Stop / Start Unavailable Service Fix Auxiliary Battery location & Replacement - YouTube

EDIT: In case that link becomes broken, it's under the front passenger seat indeed. Roll the seat all the way forward and access from the rear passenger side door. Both main and aux batteries are there. Looks like a real PITA to get out without removing the seat (for main batt.) but clearly can be done. If you do it, insulate the positive leads so they don't touch ground and short stuff out/blow a fuse.

 

Yeah there is a ton of threads on this. As you note, the batteries are connected in parallel and you can get battery voltage when you least expect it.

 

Yeah, my bad. I tried searching thread titles with "aux battery location" or similar with a WK2 filter and wasn't finding what I needed. Wasn't trying to beat a dead horse with more threads for the forum storage, promise. Searching for the auto start not ready did lead me to the aux batt quickly, then the IBS next if the batt's are ok. Thank you.

 

It's under the passenger seat. Behind the main battery.. TAKE THE NEGATIVE CABLE OFF FIRST. Then no chance of the positive BZZZT

I'm ordering a new battery today. Getting 11.6V when run is on, but not running. 11.9 when off.

Been having battery protection mode, iffy remote starts here lately. Looks like the original battery in my 2016. Getting ready for January cold weather! 🥶

Looking for a coupon code to Rock Auto and off to order...

 

Ordered! Coupon code works!

 

Nice! Time to go see if it works for me lol.

 

Saved me $8 bucks. Bad thing about RA is the shipping, $21 bucks. $11 core charges. Still cheaper than anything else around me, like Fleet Farm or OReilleys Auto.

 

284245271252260515 is good until 12/13/2024 (%5 I think) There is a thread over in the WJ section.

 

Well here's a fun one, the batteries test fine. They were both a little low on voltage, probably a combination of it being 30 degrees F here, having the lights on while removing the batteries, and using them to move the passenger seat forward to access them. But, the big batt was only 48 cold crank amps under the sticker, and the aux batt was 3 ccA below. Auto parts store said if it was theirs, they'd give them a nice deep charge before trying anything else, and hey why not try. They are the factory batt's though, 2017, but I don't want to spend $500 to replace them when they are nominally fine.

Batt's read at 14.1 volts while the engine/alternator are running.

But now the question is, do I immediately blame and replace the IBS, is that something I need the dealer to code? I don't believe so but also don't know. And then, are there any other easy and likely culprits? Or do I need to get out an amp meter and start looking for a circuit drawing them down?

Was not expecting this fun in my first week of owning this Jeep, but that's life. I don't want auto-off, but I do want my remote start feature in the cold mornings. I also don't want future electrical problems from any odd voltages.

Any and all advice on the issue is much appreciated.

 

Any and all advice on the issue is much appreciated.

IBS sensor programing it not required. It is basically a temperature/voltage/current measuring device, the intelligence for the IBS is in the PCM.

AGM batteries fail without much warning. Most suggest replacing them at 5 year intervals as a preventative measure. Yous are 7-8 years and are pushing it, but if you don't mind getting stranded and needing a jump start, press on. I think some low mileage ones here have over 10 years. ESS disabled reduces the amount of starting loads on the battery, and has a tendency to extend battery life... but there are a lot of other variables.

I see notes like this in the service manual where you want power to be removed for service there is a sequence that must be followed. :

1. Disconnect and isolate the negative battery cable. If equipped with an Intelligent Battery Sensor (IBS), disconnect the IBS connector first before disconnecting the negative battery cable.

To remove the sensor, loosen the M6 captive nut, do not remove it.

Disconnect the two-pin electrical connector

Remove the ground terminal M8 hex nut

Remove the negative battery cable from the battery terminal

Never pry on the IBS

Using a battery terminal puller, remove the battery cable terminal from the battery post

 

Fed Ex is delivering my battery tomorrow. On a Sunday?

Last night my remote start worked. Seems like if it's shut off more than 8 hours it won't work?

Nice to see what voltage levels will keep the RS from functioning.

I'll keep you posted on my results.

 

OK, new batteries in, we shall see how that goes. Now on to headlight because passenger side is out. Man that's a nightmare, even from the top and the ecu out of the way, to get that bulb to rotate out.

 

New batteries don't always come fully charged. You might want to connect them to a trickle charger overnight to top them off.

And here's some info about resetting the IBS, copied from elsewhere:

It will take 6-hours of "quiet time" for the IBS to learn the state of charge of the new batteries.
After the vehicle sits overnight it should start working normally again

If you want to reset it instantly, you can turn the key to the run position without starting the engine and then unplug the 2 wire connector that's on the IBS for about 10 seconds. When you plug it back in It will default to 95% SOC I believe. It will continue to learn so if the batteries are in fact bad, ESS will stop working again once it relearns the state of charge.

 

New batteries don't always come fully charged. You might want to connect them to a trickle charger overnight to top them off.

And here's some info about resetting the IBS, copied from elsewhere:

It will take 6-hours of "quiet time" for the IBS to learn the state of charge of the new batteries.
After the vehicle sits overnight it should start working normally again

If you want to reset it instantly, you can turn the key to the run position without starting the engine and then unplug the 2 wire connector that's on the IBS for about 10 seconds. When you plug it back in It will default to 95% SOC I believe. It will continue to learn so if the batteries are in fact bad, ESS will stop working again once it relearns the state of charge.

Good idea on the trickle charge, will do while I go back to fighting the headlights, I need to warm up a bit first. IBS reset, guess I'll have to read more on that, it's a pushbutton start on mine.

 

Good lord, those headlights were a nightmare. Is 2017 a fiat-chrysler year? I'm coming from an '08 daimler-chrysler wk that seems reasonably built with an understanding that cabin materials are garbage, blink at a non-leather seat cover and it stains. Have a sunroof?.... hahahahahahaa, welcome to it pouring water in the cabin. Other than a wet butt, that Jeep was reasonably built, at least so far, in my experience (90k-217k). The only major problem with my WK1, is the front diff bushings. But HOLY French toast, in the WK2, they are jsut headlights...I know there are worse varieties out there from other manufacturers......but still. I'm a controls engineer with a toolmaking background, what the actual F are these engineers designing? I really like this '17, she's real pretty and nice....but maybe these design engineers should spend some time in a garage before they get to design even prototype.

 

I know what you mean about the engineers and "what were they thinking" when they designed things certain ways. I'd like to see one of them change the spark plugs in my 2018 V6 GC. I did it myself with a lot of help from YouTube and casually spending most of the day on it.

When the IBS reset instructions say to "turn the key" to the Run position, it means to press the start button twice without pressing on the brake pedal. I don't know what year they stopped using a key to start the engine in a GC.

On the battery charging, connecting a trickle charger to the jump posts under the hood will work to charge both batteries once they've been installed. I top mine off that way once a month or so. I've read where some owners say they connect theirs to a trickle charger whenever it is parked at home. That seems a bit excessive, IMHO.

 

Oh ok, thanks for clearing that up for me. Will do. Trickle charged nice and slow last night, while doing headlights. Found a youtube short where a guy took a small chunk of 3/4" pvc and used a dremel to remove material to fit around the plug section of the bulb, made it SOOO much easier. Highly recommend. I don't have a garage so no way I'm charging every day or even week, especially when the real snow comes here. Maybe once a month or so on a weekend when I'm fiddling around.

 

Well, Fed Ex delivered my battery. A younger gal hoofed it to my door. I helped. She should have used a 2 wheeled dolly.

It came in a larger box with bubble wrap. Then the battery was wrapped in cardboard. It was damaged. Someone dropped it. 😕

Broke some of the plastic bits, but not enough to return it. Had this happen the last battery from them. Shipped from NY. Just a FYI

Don't plan on shipping back the old one. $11-12 core charge won't be worth it. I gave my last battery to my coworker.

 

OK, I took the AUX battery out this morning. Just getting ready to change the main battery. I started it without the AUX battery to see what it does. I just get the service unavailable message.

Tested my AUX battery, 12 ish volts. Load tested with a lamp, seems fine. Charged up and put back in. Now the service ESS is still there...

Do I have to do the.... (copy and paste)

It will take 6-hours of "quiet time" for the IBS to learn the state of charge of the new batteries.
After the vehicle sits overnight it should start working normally again

If you want to reset it instantly, you can turn the key to the run position without starting the engine and then unplug the 2 wire connector that's on the IBS for about 10 seconds. When you plug it back in It will default to 95% SOC I believe. It will continue to learn so if the batteries are in fact bad, ESS will stop working again once it relearns the state of charge.

 

I can be a bit paranoid, at times a benefit, often unuseful, but I don't know how AGM batt's are made and I'd worry about the battery flexing during impact and stuff inside not being quite right, just me, you don't have to be as paranoid as me.

Both my batt's tested ok, my aux was only down 3 cold cranking amps from nominal. Many batt's are actually underrated, 650 CCA but actually closer to 750 or such, with AGM's at least. And my bigg batt was only 50 CCA under nominal, nonetheless their ampacity wouldn't increase with charging. So I replaced both. It seems ColdCase was right from earlier, AGM's die and die fast, from reading and reviews I've come across after reading their comment. There's a guy at my local auto store that is kind of a guru into lots of vehicles, he told me on these that the aux battery is powering everything while the auto-off is active (at a stop, engine off, waiting for brake release) including ignition circuit, waiting for the signal to call the big batt to engage the starter. I kinda don't see how this is true, given there isn't a voltage potential difference between them when all is connected, but what do I know. Anyway, talking about it for a while I decided to replace the aux batt while I was there. he also told me those aren't manufactured as well as the main batt's and are usually only good for 1-2 years. Yeah, I know, lots of opinions on what brand is the best and manufactured better in such and such factory... best resource on that I found on ProjectFarm on youtube, I won't state an opinion of mine.

Can't comment on the IBS reprogramming, haven't done that myself yet.

 

...There's a guy at my local auto store that is kind of a guru into lots of vehicles, he told me on these that the aux battery is powering everything while the auto-off is active (at a stop, engine off, waiting for brake release) including ignition circuit, waiting for the signal to call the big batt to engage the starter. I kinda don't see how this is true

It is true. The aux battery provides the vehicle's juice when ESS stops the engine.

 

There is an isolation relay involved. A description of how ESS works has been posted here a few times

The last post of the following thread for example.

https://www.jeepforum.com/threads/stop-start-not-working-on-new-grand-cherokee-l.4478648/?post_id=41828572#post-41828572

FYI, testing an AGM battery like you would a flooded cell provides useless results.

 

Thanks for the link about the ESS, I had no idea. AGM vs flooded lead acid battery testing, are you referring to powering a light with it? Or me with my auto parts person using their battery tester (I don't know what tech is in that thing).

 

Parts shops should have learned the proper way to test AGMs and have the tight equipment by now. They have been doing it for a decade+.

 

Parts shops should have learned the proper way to test AGMs and have the right equipment by now. They have been doing it for a decade+.

The service manual says to use this....Around $3000 dollars.

GR8 Series

Midtronics GR8 is an all-in-one portable battery diagnostic station with comprehensive & multitasking capabilities. Perfect for busy shops with limited space.

www.midtronics.com

 

My ESS yellow light did not go out after 6 hours. Still on. Just from disconnecting it for a while. 😕

Going to try the IBS disconnect reset and see if that works...

ADD: well, I went outside to solve the problem and it solved itself. Turned ACC on, no idiot light. Run, no faults. Looks like the service ESS system went away!

Looks like it needs more like 24 hours to relearn. If one or both batteries are bad, I'd think it would not reset to normal?

ADD again: I tried remote start, worked fine. But now the unavailable service ESS is on again. Still not sure what the problem is. 🤷‍♂️

 

 

Well, I went to Fleet Farm and got a Top Don 6000 pro battery tester/charger. Download the APP and you can test it remotely! Save test results, etc..

TOPDON USA | Pro Diagnostics, Battery Service, Thermal Imaging

Your trusted partner for automotive tools: diagnostic tools, battery chargers, battery testers, TPMS, jump starters, key programmers, thermal imaging, ADAS, and EV Chargers.

www.topdon.us

Took the AUX battery out and tested it. DIMINISHED PERFORMANCE. 135 CCA. 😕

I'll probably take the main battery out or test it in the vehicle here tomorrow.

 

Some stuff I was reading suggested AGMs can be checked with the old school load test. Load it to 1/2 of rated CCA for 15 sec (or something like that), then do some voltage readings.

 

Yeah, if you know what you are doing, you can get pretty good at checking AGM batteries using old school tech. Its just different than flooded cells.

 

Anyone ever try a power sports battery for the AUX one?

Only $40 ish and the only thing I see is swapping over the stud from the battery terminals. I may try it...

Or Amazon...

Amazon.com: Mighty Max Battery YTX14-BS - 12 Volt 12 AH, 200 CCA, Rechargeable Maintenance Free SLA AGM Motorcycle Battery

Amazon.com: Mighty Max Battery YTX14-BS - 12 Volt 12 AH, 200 CCA, Rechargeable Maintenance Free SLA AGM Motorcycle Battery

www.amazon.com

Well, it's ordered! I'll let you guys know how the MM battery works!

 

Anyone ever try a power sports battery for the AUX one?

I've seen talk of it and thought about temporarily trying one out of my motorcycle for troubleshooting.

First thought for me on a permanent basis though is if it has provision to hook up the factory/OEM venting system.