Auto stop, worst idea ever just got worse.

[Lunentucker]

Took the AUX battery offline months ago.
Started making a conscious effort of turning off the ESS with the dash button as part of my startup. Now it's muscle memory and I don't even thing about it. It just happens.

Phone / Buckle / Brake / Start / Park Lights (for my Prerunners) / ESS off / Climate

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[wpduffey]

Hello, We are sorry to hear about your experience, please send us a private message once your vehicle is at the dealership, we shall provide you additional assistance alongside the dealership. Sylvia Jeep Cares

Thats funny, jeep cares, don't get me started! Not only is it a horrible idea on a gas truck, they put the d@mn thing on a diesel too.

 

[ShadowsPapa]

Hmm, I can't get mine to function this way. It always shuts off even with the lightest of pressure on the pedal.

I learned of that ability with my wife's Grand Cherokee - the 2018 she had. She told me "if you........" and explained her observations. I tried it with my 2020 and it worked fine, perfectly, in fact.
It usually works with my 2022 but it's not as good as the 2020 was, so I guess in summary - looks like there's some imperfections in how that bit works. GO FIGURE!

 

[Tommyd]

Disconnect the negative terminal from the aux battery, remove fuse 42

voila

Does this have any negative side affects?

 

[ShadowsPapa]

Does this have any negative side affects?

Not if you don't leave ESS enabled.
It's only a negative if you like to leave ESS working like I do. So I'll probably never do this.

 

[Cspence]

Can you just remove fuse 42, or do you have to disconnect the aux battery as well to effectively disable? Not sure what other implications would accompany disconnecting the aux battery, so my preference would be to just remove the fuse which I'm assuming is dedicated to the auto start stop circuit. I don't have my truck yet, but I personally can't stand the auto start stop in my wife's car.

 

[Mr._Bill]

To keep ESS from turning off the engine requires pushing the button on the dash at each startup. Using the Auto Start/Stop Eliminator, or equivalent device, does the work for you by telling the computer the button has been pressed. This provides the equivalent of an always off feature, which this ESS system does not have.

There are other hacks available that keep ESS from turning the engine off, but it is done by creating an error condition. Many of these create other issues, like preventing Remote Start from functioning.

 

[ShadowsPapa]

Can you just remove fuse 42, or do you have to disconnect the aux battery as well to effectively disable? Not sure what other implications would accompany disconnecting the aux battery, so my preference would be to just remove the fuse which I'm assuming is dedicated to the auto start stop circuit. I don't have my truck yet, but I personally can't stand the auto start stop in my wife's car.

Pulling the fuse ONLY prevents the PCM from doing a quick check of the aux battery while starting the engine - during the startup sequence.
So if you don't pull the negative cable of the aux battery off, there's nothing gained by pulling that fuse.
The fuse handles the PCR which is a relay that the PCM opens to check the aux battery.
If the fuse is pulled, it can't open the PCR and won't notice that there's no aux battery if you pull the cable.
No impact on the ESS operations at all. That's just the system where the PCM checks for the aux battery "health".

Basically, what Bill said above.........

 

[rafaelsmith]

So ive been using Tazer to "disable" ESS for about a year now without issues. Few weeks ago...I got the light and message that "ESS not working, get service"...yada yada. The button still always indicates "off" like is should using Tazer hack. I suppose I should have battery checked....but not at a dealer.

Everything to do with ESS pisses me off and has since the beginning.

 

[ShadowsPapa]

So ive been using Tazer to "disable" ESS for about a year now without issues. Few weeks ago...I got the light and message that "ESS not working, get service"...yada yada. The button still always indicates "off" like is should using Tazer hack. I suppose I should have battery checked....but not at a dealer.

Everything to do with ESS pisses me off and has since the beginning.

We've mentioned this dozens of times - it may NOT be the battery (could be, but.........) the ESS relies on dozens of other things to be correct before it gives the all-clear. So check the battery, but know that it also could be related to some other issue with the truck and it's saying "ESS can't work because ABC is broken" type of thing.

If you didn't do the aux battery bypass - simple version, by pulling the F42 and disconnecting the aux battery, it's still going to be checking it during the startup sequence - but could be another issue so be ready.
Maybe you'll be lucky and find it really is a battery problem.
You DO have a 2020 so it's likely time for batteries anyway.

 

[Tommyd]

Not if you don't leave ESS enabled.
It's only a negative if you like to leave ESS working like I do. So I'll probably never do this.

Thanks! So that’s all the aux battery takes care of? I’m sure you’ve had this conversation one to many times

 

[ShadowsPapa]

Thanks! So that’s all the aux battery takes care of? I’m sure you’ve had this conversation one to many times

Yeah, with ESS disabled (as with one of the devices from a forum sponsor, or another seller, or using a tazer) the aux battery serves no purpose.
With ESS, during a stop that battery handles vehicle electronics and certain other things.

and.................
Oh, yeah, but oh, well - what the heck.

 

[Rocksalt]

I just went with the jumperless aux bypass as oitlined by jebiruph

 

[Redleg37]

I watched a video where they did math and stuff and figured out that for a four cylinder engine, the car needs to be off for roughly 6 seconds to break even with turning the engine off and on. Mine frequently stops the engine when I'm paused slightly in city traffic. When used this way, it's actually burning more fuel than its saving

 

[ShadowsPapa]

I watched a video where they did math and stuff and figured out that for a four cylinder engine, the car needs to be off for roughly 6 seconds to break even with turning the engine off and on. Mine frequently stops the engine when I'm paused slightly in city traffic. When used this way, it's actually burning more fuel than its saving

How is it burning more?

Who put the video up? Was it real world testing on real streets, or sitting in a chair determined to disprove any savings?

Did you know that hot ESS restarts are not like pushing the big button to start it? The PCM tracks the last time every injector fired, duration, piston position and so on so that it can be restarted without taking extra fuel.
Toyota even goes so far as to have one cylinder fire to start the engine, negating any load on a starter of any kind. It's sort of like the old shotgun start diesels, or how you used to start stationary engines - fuel into chamber, fire the ignitor, engine starts without spinning it

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