2022 EcoDiesel Battery/Starting Issues Advice Needed

[Benson86]

Hi all, hoping to get a little advice before having to have it towed the the dealer. Its a 2022 Unlimited with the 3.0 EcoDiesel, it just over 3 years old and just out of the standard warranty but still under powertrain. Its a lease, and ill be giving it back in October. Both batteries were replaced under warranty at just under 2 years, so those batteries are about a year and a half old.

The start/stop recently started not working again, so I figured the AUX battery was prob going again. I tested both batteries last weekend with a basic analog load tester and the aux battery tested bad, while the main battery tested good. The jeep was still starting ok. I planned to replace the aux battery this weekend.

But while driving today, I forgot to turn off the auto start/stop, and it decided to engage while I was at a stoplight and shut off. When I took my foot off the break it went to restart and just died, didn't even try to turn over. Tried turning it off and restarting it and nothing, just clicks. Fortunately was close to a friends house so was able to push it to their yard. Pulled the AUX battery and replaced it with a new one, and then tried to use my friends car to jump it, no luck. It turns over incredibly slowly, like one revolution every second, tries for 10 sec or so, and wont start. And after failing to start the voltage seems to drop and it says all kinds of crazy crap on the dash about various systems not working until I turn the ignition off and on again. Without the jumper cables attached it wont even try to turnover, just clicks.

This is my first time owning a new vehicle that has a dual battery start stop system like this. Is it possible the main battery is also bad even if it tested good last weekend? Is it worth taking the main battery out and getting it tested/replaced? I just hate to spend another 260 on the main battery if there's something else going on and still have to take it to the dealer anyway. Very much hoping its not a starter issue as that's not covered under the powertrain warranty. Any advice is appreciated, thanks!

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[StartedWith97TJ]

Hi all, hoping to get a little advice before having to have it towed the the dealer. Its a 2022 Unlimited with the 3.0 EcoDiesel, it just over 3 years old and just out of the standard warranty but still under powertrain. Its a lease, and ill be giving it back in October. Both batteries were replaced under warranty at just under 2 years, so those batteries are about a year and a half old.

The start/stop recently started not working again, so I figured the AUX battery was prob going again. I tested both batteries last weekend with a basic analog load tester and the aux battery tested bad, while the main battery tested good. The jeep was still starting ok. I planned to replace the aux battery this weekend.

But while driving today, I forgot to turn off the auto start/stop, and it decided to engage while I was at a stoplight and shut off. When I took my foot off the break it went to restart and just died, didn't even try to turn over. Tried turning it off and restarting it and nothing, just clicks. Fortunately was close to a friends house so was able to push it to their yard. Pulled the AUX battery and replaced it with a new one, and then tried to use my friends car to jump it, no luck. It turns over incredibly slowly, like one revolution every second, tries for 10 sec or so, and wont start. And after failing to start the voltage seems to drop and it says all kinds of crazy crap on the dash about various systems not working until I turn the ignition off and on again. Without the jumper cables attached it wont even try to turnover, just clicks.

This is my first time owning a new vehicle that has a dual battery start stop system like this. Is it possible the main battery is also bad even if it tested good last weekend? Is it worth taking the main battery out and getting it tested/replaced? I just hate to spend another 260 on the main battery if there's something else going on and still have to take it to the dealer anyway. Very much hoping its not a starter issue as that's not covered under the powertrain warranty. Any advice is appreciated, thanks!

Try throwing a charger on the main battery and ensure it is fully charged before trying to start it. It is probably a good idea to ensure the aux is fully charged as well. If that doesn’t get you started, then a new main battery might be in your future .

Good luck!

 

[alphawolff]

Just replace the main battery dude

 

[wharton [SCAMMER]]

I’d still suspect the main battery. These Jeeps get super weird when voltage drops, even if it “tested good” before. A weak main battery plus a bad aux can cause exactly what you’re describing.
If it’s cranking that slow even with a jump, I’d have the main battery load tested again before assuming starter. Could also be a bad ground, but battery would be my first move.

 

[Benson86]

I’d still suspect the main battery. These Jeeps get super weird when voltage drops, even if it “tested good” before. A weak main battery plus a bad aux can cause exactly what you’re describing.
If it’s cranking that slow even with a jump, I’d have the main battery load tested again before assuming starter. Could also be a bad ground, but battery would be my first move.

Got it. Ill do that first, ill pull it and have it tested. May just end up replacing it to be safe. Thank you!

 

[Benson86]

Well I replaced the main battery. It fired right up and ran for about 20 seconds. The voltage gauge in the dash dropped to 0 extremely quickly, the flashed a message saying battery charging aux disabled. And then almost immediately after shut off and the gauges went crazy. Now it’s not wanting to start at all. Think it’s time to tow it in unfortunately. Hopefully whatever is wrong is covered under the powertrain warranty since I’ve done both batteries and it doesn’t seem like the starter.

 

[Rangemaster]

Your AUX battery is below 12 volts, had this happen in my 3.0 also. I replaced both batteries to fix the problem. There is really no way to charge the aux battery unless you pull it out.

 

[Benson86]

Your AUX battery is below 12 volts, had this happen in my 3.0 also. I replaced both batteries to fix the problem. There is really no way to charge the aux battery unless you pull it out.

Got ya. I called the dealer and they said none of it would be covered under the powertrain warranty anyway. I’m not gonna pay dealer prices, so I’ll just have it towed to house for now. At least there I can work on it in peace with all my tools. I’ll take out both batteries and charge them overnight. Give it a try tomorrow and go from there. Thank you!

 

[Jebiruph]

Your symptoms indicate a possible blown N3 fuse, so check that.

 

[Benson86]

Your symptoms indicate a possible blown N3 fuse, so check that.

Thanks for the suggestion! I was suspecting that was a possibility also after researching, and sure enough, it was indeed blown.

I replaced the fuse array, charged both batteries overnight and now im back up and running! Thanks for the advice everyone!

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