[Bob Blaylock]

I'm with you on the ASS (actually ESS)

I think ASS is by far a more appropriate acronym than ESS. I get why the mute donkeys that came up with this idea don't want it to be called by an acronym that is very derogatory, but if they didn't want there idea to be called by derogatory names, then they should have kept this stupid idea to themselves in the first place.

Anyway, between starting this post, and finishing it, I did grab a can of contact cleaner, and went out pulled this connector, sprayed some contact cleaner on it, and worked it in and out a few times.

I did end up replacing the battery, yesterday. I had run it down while I was playing with my new toy at CarMax, before I began the drive home, and by the time I was ready to leave, I had to get a jump start to get going. Flipping through the dashboard menu, after I got home, I took note that the ASS display said that ASS was unavailable because the battery was charging. That would have made sense at the start of the trip, but if the battery was good, and the alternator was good, then the battery should certainly have been fully charged at the end of a roughly 75-mile drive home. A few measurements with a voltmeter seem to confirm that the alternator was good, but the battery was weak, at best. I was getting about 12.3 to 12.4 volts on the battery with the engine not running, and about 13.8 with the engine running.

The local CarMax was booked up for the day, so no appointments available there to get them to replace the battery, but a very cute young lady there assured me that if I did it myself, they'd reimburse me the cost of the battery, so that's what I did.

 

[Bob Blaylock]

Usually that's a sign of a possible bad IBS (Intelligent Battery Sensor), and also can show up with weaker batteries and or bad connections and or grounds. I'm with you on the ASS (actually ESS), I hate it too, and wouldn't break my heart if it quit working, but yes, you don't want the warning light staring at you either. You can try cleaning the connections on the IBS. it's that little square box on the negative battery terminal. There's a couple wires and a plug. May unplug it and clean both sides with some contact cleaner, and you might get lucky. They aren't terribly expensive if you do have to replace it, $50 or so, and 5 minutes time...😁😎

Looks like I need to replace this part. I used contact cleaner on it a few days ago, but the issue still occurs.

Your picture shows a 56029777AA. Mine is a 56029777AB, and it looks like the current version is the 56029777AC.

 

[Bob Blaylock]

First thing to do would be to get your battery checked as a bad one can cause all kinds of electronic issues. Get a free check at your local auto store.

Already done. By the time I got my new toy home, it was clear that there was a problem with the battery itself. I'd managed to run it down while I was playing with it at CarMax in Fremont, and needed to jump start to get it running for the trip home. But seventy-three miles of driving from Fremont to Sacramento would surely have been enough to fully charge it, and it wasn't. I did enough tests and measurements to verify that the alternator was working correctly, that there was enough voltage across the battery when the engine was running, to charge it properly.

I wonder if an issue with one of these parts, the battery and the Intelligent Battery Sensor (IBS) led to a failure of the other, or if it's just a coincidence that the two parts failed at the same time. As long as the IBS was allowing enough voltage across the battery, and something else wasn't pushing the voltage too high, the IBS shouldn't have harmed the battery. But with the new battery, the engine-running voltage was significantly higher (somewhere just north of fourteen volts), while it was in the 13.8 volt range with the old battery, suggesting that the old battery was pulling enough current to drag the whole electrical system down. I wonder if it was pulling enough current through the IBS to damage the IBS. I'd expect the IBS to be engineered to withstand any amount of current likely to happen with a bad battery in this manner, but perhaps not.

 

[Bob Blaylock]

Usually that's a sign of a possible bad IBS (Intelligent Battery Sensor), and also can show up with weaker batteries and or bad connections and or grounds. I'm with you on the ASS (actually ESS), I hate it too, and wouldn't break my heart if it quit working, but yes, you don't want the warning light staring at you either. You can try cleaning the connections on the IBS. it's that little square box on the negative battery terminal. There's a couple wires and a plug. May unplug it and clean both sides with some contact cleaner, and you might get lucky. They aren't terribly expensive if you do have to replace it, $50 or so, and 5 minutes time...😁😎

View attachment 233080

So, I've replaced this part. More expensive than expected. Searching online, I found it for around $70 to $80, and an indication that the nearest dealer would have it for $101.00. The local dealer didn't have it, but could tell me that the nearest dealer that did was in Lodi, so I went there. $137.66 plus tax, which took it to $149.02. It was, of course, absurdly easy to replace.

 

[Bob Blaylock]

Usually that's a sign of a possible bad IBS (Intelligent Battery Sensor), and also can show up with weaker batteries and or bad connections and or grounds. I'm with you on the ASS (actually ESS), I hate it too, and wouldn't break my heart if it quit working, but yes, you don't want the warning light staring at you either. You can try cleaning the connections on the IBS. it's that little square box on the negative battery terminal. There's a couple wires and a plug. May unplug it and clean both sides with some contact cleaner, and you might get lucky. They aren't terribly expensive if you do have to replace it, $50 or so, and 5 minutes time

So, I've replaced this part. More expensive than expected. Searching online, I found it for around $70 to $80, and an indication that the nearest dealer would have it for $101.00. The local dealer didn't have it, but could tell me that the nearest dealer that did was in Lodi, so I went there. $137.66 plus tax, which took it to $149.02. It was, of course, absurdly easy to replace.

Having replaced the battery the day after I got it, and having replaced the IBS yesterday, I had run it several times without seeing the ASS error.

But just now, going out and starting it up for an entirely different purpose, to get a picture of a different screen, this came up again.

Where should I look next as far as trying to solve this?

 

[Bob Blaylock]

Is your new battery an AGM battery?

Yes,it it.

 

[Bob Blaylock]

Also make sure your door was shut and you had the wheels straight. The Jeep can throw this message if the wheels are turn one way or another.

I'll have to pay attention to that. Before I replaced the IBS, I have moderate confidence that at least some of the times it threw this error, the door was closed and the wheels were straight, but I'm not confident that that was the case this time.

 

[Bob Blaylock]

Is your new battery an AGM battery?

I see that both batteries that AutoZone offers, that it says will fit this vehicle, are AGM. I took a picture of the old battery, just before I left it behind as a core, and I see that it says it's AGM as well. I'm pretty sure that was the original battery, that this car had from the factory.

 

[Bob Blaylock]

Edit ; do you have that picture of the old battery ? The original is easy to identify, and yes it is AGM.