ESS not working?

[OddlySatisfied]

I've only had my Jeep a little over a week now. When i start it I get a warning that ESS is not working.

How can I tell if this is some sort of override installed by the previous owner or if it's an actual issue?

Honestly, I like the ESS being permanently off, but if something is wrong I'd rather fix it.

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[Bryce]

The first thing I'd check is the status of the ESS system in the in the gauge cluster. Use the left up down arrow on the steering wheel to page through the menus. it's menu 6 I think and would give you a status. there are a ton a reasons for it not being active from battery state to hear on hi or low to being at a certain angle.

The override devices like a Tazer or one of the other ones that go in the OBDII circuit will still light up the over ride light in the center stack, they just remember it's most recent state (on or off). Anything else like pulling a hood pin to detect if the hood was open would give an error on the cluster.

 

[Ratbert]

Do you have something that's causing parasitic drain on your batteries? It could also be from them simply going out. Or a bad IBS (the issue with mine that was eventually tracked down by a dealer), but that seems to be fairly rare.

 

[Reinen]

Did the Jeep sit parked for a while before you bought it? That is really hard on the batteries and it may have done them in. ESS is the first system to shut down when batteries start to fail.

If you do replace batteries always replace Main and Aux at the same time. Otherwise battery lifespan will be severely reduced.

 

[MauiSteve]

My 21 JLR 6 speed ESS has never worked. I don't want it fixed and have not tried to get it fixed.

 

[Ratbert]

My 21 JLR 6 speed ESS has never worked. I don't want it fixed and have not tried to get it fixed.

It's a symptom of something else being wrong with your Jeep. Possibly batteries? Possibly IBS? Maybe something else?

 

[OddlySatisfied]

Did the Jeep sit parked for a while before you bought it?

I think it was first put on the lot in August and I bought it this month (October). I don't know how often it was test drove or anything though. It has 60,000 miles, so I figure the previous owner kept it on the road quite a bit.

Do you have something that's causing parasitic drain on your batteries?

There doesn't appear to be any issue with that. There have been a couple days at a time that I haven't driven it. When I did drive it, it wasn't slow to start or anything, it seemed to turn over the engine at the same rate.

I'll check for loose cables on it tomorrow. I probably again won't drive it Sunday or Monday. I check the voltage when I get out and again just before I drive it again to see if it has drained any.

 

[tomk62]

I've only had my Jeep a little over a week now. When i start it I get a warning that ESS is not working.

Your 2020 Wrangler? The batteries need to be replaced. They are at the end of their useful life.

 

[AndySpill]

My 21 JLR 6 speed ESS has never worked. I don't want it fixed and have not tried to get it fixed.

Hey Steve:

I get that ESS isn't your "cup of tea." But as you may know, but I'll mention anyway in case you don't--or others don't--there are notable differences between an ESS system that fails to engage on its own, and one in which the owner/operator has not only expressly taken steps to prevent it from engaging, but even more important, disconnected components from the vehicle that are used in the ESS system's operation.

To this point, if ESS isn't your thing, and you are running a dual AGM battery JL I would recommend that you, in addition to turning the ESS system off by button push (and that button push can come care of your own finger or after market tech--it's all good to me) that you disconnect the Aux battery--which can be problematic and has little function if not running ESS events--from the vehicle's electric schematic, and prevent the vehicle from ever isolating that Aux battery by pulling Fuse 42 from the PDC (Power Distribution Center)--i.e. your vehicle's intelligent fuse box, which is black in color, and resides on the top of the engine bay on the passenger's side.

Taking the Aux battery out of the electrical schematic of the vehicle involves visualizing the two black factory cables the sit on the negative terminal of the main battery, and removing and insulating the end of the cable whose other end does not connect to the body ground on the passenger's side front fender area. Leave this latter cable connected. The other cable I would have you disconnect has at its unseen distal end the negative terminal of the Aux battery, and by disconnecting it at the main battery you take the Aux battery out of the vehicle's ability to tap it for power or charge it.

Dual AGM battery JLs will, at cold crank, attempt to energize the PCR (Power Control Relay), which when powered, temporary separates the two batteries and energizes the vehicles appliances/electronics only on the Aux battery. This happens for only an instant at cold crank to test the Aux battery, and during the duration of ESS events to run appliances off this Aux battery until the engine re-cranks.

Pulling Fuse 42 silently, with no error messages, prevents the PCR from being energized. The cold crank test then occurs against all available batteries, of which you only have the main battery connected, and thus, only against the main battery.

 

[Reinen]

I think it was first put on the lot in August and I bought it this month (October). I don't know how often it was test drove or anything though. It has 60,000 miles, so I figure the previous owner kept it on the road quite a bit.

2 months? That's probably the root of the problem right there. Dealers are notorious for not maintaining the batteries of their lot vehicles. The batteries were probably already worn a bit from the previous owner's normal use (check the date on the battery) and the stress of being slowly drained over 2 months did them in. JL batteries generally last 2 to 4 years without the stress of sitting parked for that long without a trickle charger.

But it's a somewhat expected issue with modern vehicles with always-on electronics. It's an easy enough fix and you know you'll be good on batteries for a good while. Just always replace both batteries at the same time. A new battery paired with an old battery will die prematurely.

 

[OddlySatisfied]

Thanks for the replies.

I haven't done anything to the Jeep yet. I was hospitalized for sepsis earlier in the week and I'm just now getting to feeling like doing anything.

Are any batteries in particular recommended for the Jeep? Is just a regular battery set up from O'Reilly's or wherever good enough?

 

[YBABRAT]

When I got my used rubicon, it sat for a good while before I got in and drove. I had no idea ess was automatic until a few hundred miles down the road. In the early stages no indecation of ESS warnings until I restarted after stopping at rest stop. The instrument cluster had a warning ess will enable once aux battery has charged.... something like that.

 

[OddlySatisfied]

Just wanted to add a reply for any future searches.

It was indeed the auxiliary battery that was causing the issue in my case. It was only operating at 10.38 volts when I got it out.

The main battery was almost brand new, not much older than the length of time I've owned the Jeep. Someone was kind enough to have left a receipt from Advance Auto with the information in the glove box. I just didn't find it until recently.

Hopefully it didn't damage the main too bad operating with a low aux. I guess I'll find out eventually. Although, it tested good at O'Reilly's (where I went for the replacement aux).

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