Aux battery vs remote start?

[IQ_imbalance]

Does anyone know if the aux battery is required for the factory remote start feature? Thanks!

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[Rhinebeck01]

Does anyone know if the aux battery is required for the factory remote start feature? Thanks!

@IQ_imbalance

You can bypass the Aux battery or delete the Aux battery altogether and the JL's remote start will still work as designed.

 

[Fudster]

Bob, I don't know. Jerry @Jebiruph would. That said, and I don't mean this arrogantly---technically you are, IMHO, asking the slightly wrong question. Please let me explain.

The question best asked here is "does anyone know if calls to the aux battery by the vehicle have to provide electrical current for the factory remote start feature?"

What's the difference...? Your dual AGM battery JL has those batteries connected in parallel (positive terminal to positive, negative to negative) at all times but an instant at cold crank to test the ESS/Aux battery and during ESS events.

This separation happens by the vehicle energizing a relay that separates the batteries. If you go into the Power Distribution Center (PDC), that black box closest to the passenger's seat, under the hood, and pull its cover off (your intelligent fuse box) and yank Fuse 42, that relay will not get the power to separate the batteries.

This means that all calls for electrical current to either or both batteries will now go to whatever battery or batteries you have connected.

In English: even if remote start required an energized ESS/Aux battery, yanking Fuse 42 will trick the vehicle into thinking the ESS/Aux battery has power because the vehicle's attempts to isolate it from the main battery will fail when this fuse is yanked, and the main battery will supply the power that makes the vehicle think it got that power from the ESS/Aux battery.

So I don't know the answer to your question. But pulling Fuse 42 should allow remote start to work even if it is solely dependent on an energized ESS/Aux battery.

Do turn off ESS if running with just a main battery.

 

[IQ_imbalance]

Thanks!!!! Not really an issue now, but eventually might want to temporarily/occasionally isolate the aux battery when in the boondocks and using power without the engine cranked....

 

[Fudster]

Thanks!!!! Not really an issue now, but eventually might want to temporarily/occasionally isolate the aux battery when in the boondocks and using power without the engine cranked....

If you know, when isolating the batteries (it could be either battery) and using one of them on appliances, which of the two batteries you had in mind to be the off-road appliance battery and which one the cranking battery I could guide you with the hardware and procedure to to this.

Truth is a fully charged ESS/Aux battery can alone crank a dual ABM battery JL. Truth also is that if I was taking this route, I'd probably want to use the ESS/Aux battery as my off-road appliance battery and the main larger one as my cranking one.

While owners who do what you describe regularly might best address this with a Genesis Offroad system, the gentlemen who I referred to earlier has a great thread on how to isolate batteries temporarily and even monitor their voltage together or independently. Such a scenario could provide you with enough battery power as your gasoline engine allows--permitting you to drop a battery's voltage on appliance usage, but not below threshold to crank the engine, which then could charge your battery/batteries back up.

 

[rhocking]

Does anyone know if the aux battery is required for the factory remote start feature? Thanks!

Pretty sure the answer is No. I have fuse 42 out and Aux battery Negative cable disconnected and Remote Start works without issues,

FYI I also have a Smart Stop Start because I don't like having to press the 'turn off' button and don't like the auto stop-start 'feature' and running with the Aux out of the loop it is not recommended to use ESS.

 

[O)()()()()(O]

Bumping thread because I pulled #42 and disconnected the negative. Remote Start would not work.

Does order matter? Should negative be disconnected , then fuse 42 pulled?

Curious if anyone else had this issue.

2020 JLUR.

 

[Saddle Tramp]

I have an issue we have not been able to diagnose and was wondering if anyone had a similar issue.
If my Jeep sits for several days the remote start will not work. Doors lock and I just get a click but nothing happens. I have tried this from both in and out of the vehicle. However if I push the button she starts right up. If am using the Jeep daily remote start works perfectly .
This makes me think I have a battery going bad. Not the main battery since it starts by pushing the dash button. According to the dealer the aux battery is not used during remote start.

I was wondering if anyone had a similar issue before I just trust my judgement and replace the aux battery.

Thanks in advance

 

[X-SoLjA]

I have an issue we have not been able to diagnose and was wondering if anyone had a similar issue.
If my Jeep sits for several days the remote start will not work. Doors lock and I just get a click but nothing happens. I have tried this from both in and out of the vehicle. However if I push the button she starts right up. If am using the Jeep daily remote start works perfectly .
This makes me think I have a battery going bad. Not the main battery since it starts by pushing the dash button. According to the dealer the aux battery is not used during remote start.

I was wondering if anyone had a similar issue before I just trust my judgement and replace the aux battery.

Thanks in advance

Bumping this as my brother in law's jeep is doing exactly this as well. Literally just performed the AUX delete (Removed Fuse 42, disconnected the AUX Negative terminal), as his Aux battery is most likely failing and leading to his main requiring jump starts.

Has anyone confirmed or know why this might be? The day we bypassed the AUX, we performed a regular start of the jeep to confirm all was working. Immediately after it started fine, we then decided to test the remote start. Again, remote started without any issue. He now noticed as above, if it's left overnight, coincidentally freezing cold\snowing in Canada right now which may or may not attribute to an issue with his main battery, the jeep won't remote start, but will start regularly by pressing the button inside without any issue.

Is it possible the AUX battery was providing very low trickle of power to the remote start components that then go dormant after a period of time?

...If I've learned anything form this whole ordeal and the bypass of the AUX, your simply just fooling the jeep to think the main is the aux, since they would previously have just been wired in parallel until removing it. Now the components just see the main battery and operate as if the aux was still there. Maybe his main is a little too far gone now to satisfy the remote start from cold? Keep in mind, the battery he has is original 3 year old H6. Maybe its time to swap out to an H7?

 

[andy29847]

The 2 batteries in your Jeep effectively function as one. The main battery is always involved when cranking the jeep. Remote start is functionally the same as a "cold" start. This means the battery (or batteries) has to pass a test before features like remote start, stop/start, and auxiliary switches will work.

 

[X-SoLjA]

The 2 batteries in your Jeep effectively function as one. The main battery is always involved when cranking the jeep. Remote start is functionally the same as a "cold" start. This means the battery (or batteries) has to pass a test before features like remote start, stop/start, and auxiliary switches will work.

yeah understood. Which is what I think I slowly eluded to in my post edit right as you were possibly tying this :P

Thinking maybe his main battery is just not satisfying the requirements at that time to start it remotely...

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