2023 2.0 Service Start/Stop System

[NWJeepr]

Just under 5600 miles.

Jeep has been kept plugged into a 4-amp tender since new, when it’s not being used.

After receiving the @! Warning on the dash and parking it at home, I left it on a tender overnight. Tender says battery/ies are charged.

This morning, the @! Warning persists. Noticed even after a full charge, voltage is pegged at 14.3v when engine is running, and didn’t come down over a 10 mile drive. Lights, HVAC, wipers, anything that draws big current is turned off.

I’ll check resting battery voltage when I’m home. But if battery voltage is 12.6 at rest, what else am I looking for?

I’ve read about BIM and a voltage regulator/sensor that can go bad. Any diagnostic tips on those?

Jeep is under warranty, I just don’t want to jump through hoops with the dealer yet. If batteries test bad, I’m removing the ESS battery for good.

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[dchemphill1]

Get the small battery out and run without it. It is a poor design that will take you main battery down with it.

 

[Remorseless]

eTorque or normal battery setup? High amperage stuff being down also makes me cautious about the high amp fuse array, though.

 

[Reinen]

How long was that Jeep sitting on the lot? Dealers are notorious for not maintaining the batteries of their stock. Even with 5k mi the batteries could be shot from being allowed to run down multiple times.

 

[NWJeepr]

eTorque or normal battery setup? High amperage stuff being down also makes me cautious about the high amp fuse array, though.

Non-eTorque, just the normal setup for a 2.0 with ESS only. Big battery and small battery.

It's not that high voltage stuff isn't working, it's that I had accessories with a big draw turned off to see if I could get the alternator to come down from 14.3. It charged at that voltage for the whole drive, on a fully charged battery. That indicates to me a battery might be bad, just at face value.

Edit: Oh, I see what you might be saying. N1 is a high voltage fuse for ESS on the high voltage array. I'll look.

How long was that Jeep sitting on the lot? Dealers are notorious for not maintaining the batteries of their stock. Even with 5k mi the batteries could be shot from being allowed to run down multiple times.

Built 3/23 and purchased early 5/23. It just doesn't get driven much, which is why I keep it on a tender at home. I was trying to be mindful of potential ESS problems and battery drain, and here I am anyway

 

[Remorseless]

Non-eTorque, just the normal setup for a 2.0 with ESS only. Big battery and small battery.



Built 3/23 and purchased early 5/23. It just doesn't get driven much, which is why I keep it on a tender at home. I was trying to be mindful of potential ESS problems and battery drain, and here I am anyway

Other than load testing both the batteries independently, the high amp fuse array is something I'd check for damage.

Can see where it is here:

 

[Nokones]

When I was installing my second Motorola radio, I was constantly turning on the accessories without running the engine and of course when I turned on the accessories the headlights would come on and there was no doubt that I was running down probably both batteries. After, I finished the installation, I went for a short drive, and I got the service warning.

Prior to that I only had a few short drives, maybe not more than 10 miles and that is not enough driving to recharge the batteries from the several starts.

So, I put a charger on the car to recharge the batteries and the start stop service warning went away.

 

[NWJeepr]

When I was installing my second Motorola radio, I was constantly turning on the accessories without running the engine and of course when I turned on the accessories the headlights would come on and there was no doubt that I was running down probably both batteries. After, I finished the installation, I went for a short drive, and I got the service warning.

Prior to that I only had a few short drives, maybe not more than 10 miles and that is not enough driving to recharge the batteries from the several starts.

So, I put a charger on the car to recharge the batteries and the start stop service warning went away.

Yep, I've tried this exercise with letting the batteries charge overnight and still got the warning light/icon in the morning. But that is a good way to double check it's not caused by the user, worth doing if anyone else runs across this thread.

 

[NWJeepr]

Hell with it... it's going to the dealer. This is why I have a newer vehicle under warranty. Wednesday AM, they said they'll need it all day. Probably want to charge the batteries, let it sit for a specified amount of time, and then conduct their tests. Fingers crossed for two brand new batteries.

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