Service stop/start system warning light

[mwilk012]

How long did it take the new batteries to work in your case? Days or a certain # of miles?
Before getting new batteries: 2018 JLRU had the A! Warning light came in first. Then the engine light. Both disappeared. Appeared again at different times on different drives. I Took back to dealership who plugged in, etc... 50k miles and no info provided. They saw nothing. 1 miss fire ant that was it. On the drive home the A! And engine lifht came on, but the scary thing was a churning engine and reduction in power on the highway. We haven't been driving it regularly for 2 years so we took to mechanic who ran the computer, no other info, but only the 1 miss fire. Checked batteries and since lower... Noa 3-1/2 year old batteries were changed. We drove it home Tue night with 2 new batteries. all good without warning lights. The Bluetooth recognized the phone, the garage opener worked, etc. Drove it again Saturday and the A! Light came on. Later that afternoon both the A! And the engine light came on. Same as the previous week the A!, engine lights, and "stop/start" message. We never got a "low battery " warning.
I read here in the threads about the fuses not pushed in all the way. We haven't checked the fuses today. We will...

The fuse myth never fixes anything.
It is very likely that your ESS fault light is on due to the engine fault. An active check engine light will disable ESS. Check the codes and see what comes up. Which engine is this?

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[Its Brian with an I]

I personally don't like the start/stop feature and am glad mine isn't working. Mine wasn't working when I bought the Jeep (used). I have a manual and the idea that extra second or two for the engine to restart isn't ideal. I do have a question though...is it something I NEED to get fixed? Will anything happen if I just continue to drive with the system not working and the light on?

 

[Rhinebeck01]

I personally don't like the start/stop feature and am glad mine isn't working. Mine wasn't working when I bought the Jeep (used). I have a manual and the idea that extra second or two for the engine to restart isn't ideal. I do have a question though...is it something I NEED to get fixed? Will anything happen if I just continue to drive with the system not working and the light on?

@Its Brian with an I

Well, especially if your 2018 JL still has the 2 batteries that it left the factory with, then your 2 batteries have aged out and need replacing.

Also, with some 2018 JL's, if the Aux battery dies/becomes depleted your JL will not start, even if the Main battery is aok.

Can tell you that undoubtedly, you will, in the very near future... be faced with a no start situation thanks to battery(2) related reasons.

There are many posts discussing the dual battery system, ESS, etc.. Do read/research. Do address this battery thing with your 2018 JL, ASAP.

 

[am1978]

@Its Brian with an I

Well, especially if your 2018 JL still has the 2 batteries that it left the factory with, then your 2 batteries have aged out and need replacing.

Also, with some 2018 JL's, if the Aux battery dies/becomes depleted your JL will not start, even if the Main battery is aok.

Can tell you that undoubtedly, you will, in the very near future... be faced with a no start situation thanks to battery(2) related reasons.

There are many posts discussing the dual battery system, ESS, etc.. Do read/research. Do address this battery thing with your 2018 JL, ASAP.

@Rhinebeck01 has the best advice. What batteries are best? Wife’s JL is a 2018, zero issues so far. Planning to replace batteries soon here. Which two?

 

[Rhinebeck01]

@Rhinebeck01 has the best advice. What batteries are best? Wife’s JL is a 2018, zero issues so far. Planning to replace batteries soon here. Which two?

@am1978

First off, do know that you can, without problems run with just the Main and not bother replacing the Aux battery. That is what I have been doing.. Running on just the Main for 60,000+ mi.

If you do want to replace both batteries:

A JL or JT with tow package leaves the factory with an H7-AGM Group Size 94R Main battery.

A JL or JT without the tow package leaves the factory with a Group 48 H6 Main battery, which is a tad shorter in length then the H7-AGM Group Size 94R.

With that said, if you go to install an H7-AGM Group Size 94R battery in a JL or JT that left the factory with a Group 48 H6 battery you will, in order to install the H7, have to remove a small plastic stay you will find fastened into the bottom of the Main's battery holder box. The stay comes out very easily.

For those replacing your JL or JT's Main battery... you are best served going with a higher CCA H7 versus installing a lesser CCA H6. Should also mention that often you will find the H7 costs the same as an H6.

Note: When buying an H7 is is prudent to first remove your current Main battery and measure the length of the box with the plastic stay removed. Compare that length measurement to the physical length of the H7 battery you are thinking about buying..

For your JL/JT , here are some H7's that are known to fit the JL/JT Main battery box with the stay removed:

Interstate MTX-94R/H7 850CCA 80 Ah AGM
Odyssey Performance AGM94R H7 L4
Super Start Platinum H7 SSB94RPLT
NAPA P/N 9894R H7
Batteries+ X2 Power H7 Group 94R SLI94RAGMDP
EverStart Platinum AGM Battery, Group Size H7 (12 Volt 850 CCA) (Walmart)


For Aux battery:
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.

For Aux battery change the easy way and more battery related info read here:
https://www.jlwranglerforums.com/fo...ent-the-easy-way-pull-the-fender-flare.56807/

.

 

[Rico1111]

I replaced mine with Odessey and Braille

 

[Rico1111]

I should add Thanks to Rhinebeck01! He is a wealth of knowledge!!!

 

[Rico1111]

I do still have my Start/stop and ESC service happening though and finally had the chance to get the service tech read it while it was happening...vacuum pump on order. Every other chance once it shuts down code is not left and sporadically comes and goes.

 

[devicemanager]

Last year (April) my ESS stopped working with a service stop/start system error after disconnecting the negative battery terminal to service something. Not a huge deal since I don't care for ESS, and now I don't have to press the disable button.

The main battery died a couple of months ago, so I bought a new AGM (H6). ESS was still broken and throwing up the icon in the gage cluster. I went out of town for 2 weeks, and when I returned a few days ago my fob wouldn't open the door remotely. I have no idea how many days it sat on a drained battery. My dmm showed a 3.5v charge, and when I tried to jump it the reading was 7.5v. Needless to say it would never start. Got the new battery replaced under warranty since it failed the load and charge test. Hooked up the new battery and now ESS is working again.

 

[Ney Kerestegian]

My ESS sport working 1 year ago, never had any warning light regarding that problem. 6 Month ago I apparently I had a loose ground wire and all this lights came ON. Beside the ESS not working (which I really dont care) I dont have any other issue, but I want to clear all those lights. There is any way how to clear this lights? Will a OBD2 scanner clear all this codes? Does anyone know what is causing all this lights not to turn off? I changed both my batteries 1 month ago.

2019 JEEP WRANGLER JLU 3.6

 

[mwilk012]

My ESS sport working 1 year ago, never had any warning light regarding that problem. 6 Month ago I apparently I had a loose ground wire and all this lights came ON. Beside the ESS not working (which I really dont care) I dont have any other issue, but I want to clear all those lights. There is any way how to clear this lights? Will a OBD2 scanner clear all this codes? Does anyone know what is causing all this lights not to turn off? I changed both my batteries 1 month ago.

2019 JEEP WRANGLER JLU 3.6

well for one, you need to put some gas in it. Then, you need to fix the actual problem.
Lastly, clear the codes.

Did you remove the fender liner to access the auxiliary battery or remove the fuse box / PDC?

 

[Ney Kerestegian]

well for one, you need to put some gas in it. Then, you need to fix the actual problem.
Lastly, clear the codes.

Did you remove the fender liner to access the auxiliary battery or remove the fuse box / PDC?

I Removed the fender Liner. The jeep rides amazing, don´t notice any difference on it since I got all my lights ON. Wonder if I will be able to clear all the codes with a cheap OBD2 scanner.

 

[mwilk012]

I Removed the fender Liner. The jeep rides amazing, don´t notice any difference on it since I got all my lights ON. Wonder if I will be able to clear all the codes with a cheap OBD2 scanner.

The throttle control system fault should immediately clear on restart. Something isn’t right.

 

[Ney Kerestegian]

The throttle control system fault should immediately clear on restart. Something isn’t right.

Do you know if does exist any sensor related to the throttle body? I have been looking more info about it but dont found any. In the dealership they said I might have something wrong with the Throttle body, but if that would be the case I should feel something unusual in the Jeep (and is not the case).

 

[CarbonSteel]

Did you short anything when changing the battery and did you separate the cables? You may have blown the high fuse array (N3 position).

A OBD scanner will clear the codes unless they are persistent in which case once the condition that caused the code has been rectified, then they will clear automatically.

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