Replaced auxiliary battery and auto start/stop still not working and hood ajar light on.

[Wherescaro]

2018 JL Sahara 3.6l auto 55600 miles

Service stop/start light on and hood ajar light as well. Remote start also doesn’t work.

replaced auxiliary battery and ESS still not working and lights still on the dash. Cleaned the grounds to the side by fender and made sure everything was tight when replacingthe auxiliary.

Thoughts? Could it be main battery? Could it be can buss connector? Where would you go from here as far as next steps? Jscan is now throwing a ton of low voltage codes.

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[av8or]

I had a similar problem and it was the hood ajar switch. Apparently the auto start stop won’t work if it thinks the hood is open. I replaced the switch (I think it was $14) and all has been good the last couple months.

its possible you have a similar problem.

 

[Rhinebeck01]

@Wherescaro

Have you used JSCAN to or in an attempt to turn off ESS?

JSCAN fools with the plunger that if the JL sees/ thinks is not compressed will not let remote start to work, hood adjar stuff and ESS to not function...

JSCAN may be a causitive factor in regard to your issues.

 

[Wherescaro]

@Wherescaro

Have you used JSCAN to or in an attempt to turn off ESS?

JSCAN fools with the plunger that if the JL sees/ thinks is not compressed will not let remote start to work or ESS to function...

JSCAN may be a causitive factor in regard to your issues.

Not to turn off ESS, no. But to turn off the hood ajar light yes I did.

After changing the aux battery today I went in jscan and “reset all modules” under the auto start/stop and both the hood ajar setting. Do I maybe need to drive around a bit for the lights to turn off? I also don’t understand why it’s throwing all the low voltage codes for like everything in my jeep now.

 

[Rhinebeck01]

Not to turn off ESS, no. But to turn off the hood ajar light yes I did.

After changing the aux battery today I went in jscan and “reset all modules” under the auto start/stop and both the hood ajar setting. Do I maybe need to drive around a bit for the lights to turn off? I also don’t understand why it’s throwing all the low voltage codes for like everything in my jeep now.

Sounds possibly JSCAN related..

Assure all settings you fooled with with JSCAN are changed back to what they were.

Reset ECU, twice and exit. See if all gets remedied.

You may have to clear the codes you are seeing.

 

[WranglerMan]

As stated go back into JSCAN and reverse what you did, if not sure what was turned off you can use the Trace & Restore function within JSCAN..
JSCAN does not handle ESS as well as the Tazer but other than that JSCAN works well but is a bit more Expensive “ Techie” and requires more from the user.

It’s a dam shame an owner has to go thru this crap when changing a battery which is one of the most common things one replaces on a vehicle, FCA engineers should have there a$$es whipped for such a crappy design.

 

[Carolina Jeeper]

Did you verify the voltage of the new battery previous to installing it? Also. Check voltage of the batteries after install was completed with engine off and while engine is running. Something as simple as a voltage drop caused by a faulty new battery or loose connection.

Trust me a new battery can be bad too. Seen several over the decades, so don't ignore the possibility.

 

[Wherescaro]

As stated go back into JSCAN and reverse what you did, if not sure what was turned off you can use the Trace & Restore function within JSCAN..
JSCAN does not handle ESS as well as the Tazer but other than that JSCAN works well but is a bit more Expensive “ Techie” and requires more from the user.

It’s a dam shame an owner has to go thru this crap when changing a battery which is one of the most common things one replaces on a vehicle, FCA engineers should have there a$$es whipped for such a crappy design.

I agree. It’s a pain in the butt to replace the aux battery. And the amount of crap that it runs is a problem as well. Too many electronics

I did go through Jscan and reset everything back to the way it was and both the hood ajar and auto start/stop lights still on. What a headache it is to try and figure this out.

 

[Wherescaro]

Did you verify the voltage of the new battery previous to installing it? Also. Check voltage of the batteries after install was completed with engine off and while engine is running. Something as simple as a voltage drop caused by a faulty new battery or loose connection.

Trust me a new battery can be bad too. Seen several over the decades, so don't ignore the possibility.

Meant to check battery before putting it in and completely forgot. Unfortunately getting to it is not easy. It’s an entire process of removing main battery, fuse box and then you can get to the aux battery. What a headache.

 

[Wherescaro]

Sounds possibly JSCAN related..

Assure all settings you fooled with with JSCAN are changed back to what they were.

Reset ECU, twice and exit. See if all gets remedied.

You may have to clear the codes you are seeing.

Reset it twice, changed settings back and cleared codes. Lights still on. Appears I have a larger problem on my hands than we hoped for.

 

[Rhinebeck01]

@Wherescaro

Was not me in this thread whining about the aux battery or the dual battery system..... the "design" , that was someone else...

Did you attempt to clear the codes?

---So, you dismantled the power distribution center (PDC) to get to the Auxiliary battery? I would never have done that..... doing so may have led to your issues...to issues in general.

 

[Wherescaro]

@Wherescaro

Was not me in this thread whining about the aux battery or the dual battery system..... the "design" , that was someone else...

Did you attempt to clear the codes?

---So, you dismantled the power distribution center (PDC) to get to the Auxiliary battery? I would never have done that..... doing so may have led to your issues...to issues in general.

How else would you get to it then? I was having the problem with the lights on the dash before we did any of that. According to dealer aux battery would have been their first go to. Yes, I did clear the codes.
Thank you for your help.

 

[hoag4147]

How else would you get to it then? I was having the problem with the lights on the dash before we did any of that. According to dealer aux battery would have been their first go to. Yes, I did clear the codes.
Thank you for your help.

Let’s see if I can beat @Rhinebeck01 to it

https://www.jlwranglerforums.com/fo...ent-the-easy-way-pull-the-fender-flare.56807/

 

[Wherescaro]

Let’s see if I can beat @Rhinebeck01 to it

https://www.jlwranglerforums.com/fo...ent-the-easy-way-pull-the-fender-flare.56807/

Thanks. Too late now I suppose though.

 

[Rhinebeck01]

How else would you get to it then? I was having the problem with the lights on the dash before we did any of that. According to dealer aux battery would have been their first go to. Yes, I did clear the codes.
Thank you for your help.

@Wherescaro

To change out the Aux battery ....Dealership Tech's don't dismantle the PDC... Stellantis and their Service Manager requires them to peel back the fender liner... Even easier way is to pull the flare.
https://www.jlwranglerforums.com/fo...ent-the-easy-way-pull-the-fender-flare.56807/

Lots of info on the forum in regard to the Aux battery.... Also, research about the "high amp fuse array" in the PDC.

.

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