Remote start not working - AUX battery the culprit?

[woodthecrab]

I've got a '21 Gladiator with the original batteries. Showing 14.5 volts on the dash while running.

The last two mornings, I activated remote start and got the usual horn / light response, but it did not start. When I got to work this morning - about a 30 minute drive - I turned off the car and made for the entrance. I decided to try the remote start, and it worked.

I haven't experienced any hesitation with regular starts, but I know my batteries are probably getting near the end of their lives.

Is it a fair hypothesis that the remote start isn't working on cold starts because the AUX battery is cooked, or does anyone have an alternative theory?

Thanks for your time and input!

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[JTdiRtyD]

Long story short, yes you likely need batteries. With their age they aren't maintaining charge after sitting.

The reason it appears to start fine with normal starts is the system isn't as sensitive to battery output, but it is sensitive for remote starts. The reason it remote starts fine after just shutting it off is the output is higher than 80% because it was just actively being charged, but as the truck sits after being shut off and your batteries bleed off stored power, once the battery drops below ~80% (best guess of a percentage, I don't know the actual number) it will cancel remote starts.

The IBS in these trucks doesn't actually charge until battery output drops below 80%, until then it's just providing low amps to maintain. Once it detects below 80% it charges to 100% before going back into a maintenance mode. Since you're seeing 14.5v on the dash this tells me your truck is actively trying to charge, so its seeing output was below 80%.

In addition to this, colder temps negatively effect battery output, so an already weak battery will bleed stored power even faster.

 

[woodthecrab]

Thank you for that detailed response! Makes perfect sense. At least the winter is nearly over, but I'll have to hit the batteries soon.

 

[Andy29847]

I'd say the failure of remote start to work first thing in the morning is a sign that your batteries are getting weak. It is impossible to say which battery is causing the problem using just the noted remote start issue. However, if you have a 2021 and the batteries are the original ones, I'd recommend new batteries soon.

FWIW, I only run one battery in my Gladiator. I use an Everstart H7 AGM battery from Walmart that has as much power as both Mopar batteries. I also use a Smart Stop/Start device to disable the ESS Stop/Start system.

https://www.jeepgladiatorforum.com/...remium-h7-group-94-battery.76866/post-1254668

 

[DenCoGladiator]

I had the same issue this winter....2021 on original batteries with remote start not working, but started just fine with push button ignition. I replaced both main and aux batteries and works fine now.

 

[woodthecrab]

I'd say the failure of remote start to work first thing in the morning is a sign that your batteries are getting weak. It is impossible to say which battery is causing the problem using just the noted remote start issue. However, if you have a 2021 and the batteries are the original ones, I'd recommend new batteries soon.

FWIW, I only run one battery in my Gladiator. I use an Everstart H7 AGM battery from Walmart that has as much power as both Mopar batteries. I also use a Smart Stop/Start device to disable the ESS Stop/Start system.

https://www.jeepgladiatorforum.com/...remium-h7-group-94-battery.76866/post-1254668

Nice tip on the batteries. I overpaid for my wife's at AutoZone, it appears.
Love that stop/start delete option, but at $130, I think I'll keep pushing the button for now, LOL.

 

[In3briatedPanda]

my remote start did this as well and my main battery was my culprit.

my aux is still the original from 2021. My ESS still works too. Only noting bc its a unicorn scenario lol

 

[G J]

A couple of other things will interrupt remote start I have found...If your low fuel light is on and you need gas it will not engage remote start. Also if one of the electrical connection plugs to your doors has an issue or is unplugged it will not engage remote start. I had my doors off and when I put them back on I didn't have the plugs aligned well on passenger side. A few pins got bent and were not making connection. Took a while to realize the issue because the electric window still rolled down but the electric mirrors would not adjust. Pulled the connection and found the bent pins. After I straightened then and re-established a good connection my remote start started working again.

 

[berb]

Thank you for that detailed response! Makes perfect sense. At least the winter is nearly over, but I'll have to hit the batteries soon.

Yes sooner rather than later. The remote start intermittently having issues is your warning before the jeep will not start at all. I found that out the hard way when we were on vacation and our Wrangler wouldn't start. I ignored the remote start issue and a month later I was stuck. Got new batteries and all was right.
The Aux battery is a pain in the ass! If the aux battery was going to cause issues then jeep should have made it easily accessible.

 

[woodthecrab]

Yes sooner rather than later. The remote start intermittently having issues is your warning before the jeep will not start at all. I found that out the hard way when we were on vacation and our Wrangler wouldn't start. I ignored the remote start issue and a month later I was stuck. Got new batteries and all was right.
The Aux battery is a pain in the ass! If the aux battery was going to cause issues then jeep should have made it easily accessible.

I know the AUX battery has been much discussed, but to me, it's pretty simple. The manufacturer wants to deter DIY maintenance through over engineering something that was best left simple. Most won't people won't tackle the AUX battery and will pay the ransom to the dealer or mechanic for something nearly anyone could do who is willing. I'm not that handy, but I followed a YouTube video and did the batteries on my wife's '21 Wrangler in 45 minutes. I'll do the same with mine in the next couple of weekends.

 

[Lost1wing]

My remote start works every morning and so does ESS. I still have my original batteries in my 2020 (2019 build). I had a few moments where the ESS did not work or I should say, the battery charging message stayed on.

I didn't drive the JT much in the beginning and I related my issue to that. I have kept the NOCO 2d plugged in when I know it will be parked for a few days. If I got in it today, I would see battery charging for an hour or so. An IBS reset after a full charge does not change that. I still have to drive an hour for ESS to be ready.

I know it's time to replace both batteries, I am just waiting for the dealership to take care of the corrosion repair first. No sense installing new batteries only for them to drain while it sits at the bodyshop. 2 days has already turned into 4 days already.

 

[S JEEPN]

I know the AUX battery has been much discussed, but to me, it's pretty simple. The manufacturer wants to deter DIY maintenance through over engineering something that was best left simple. Most won't people won't tackle the AUX battery and will pay the ransom to the dealer or mechanic for something nearly anyone could do who is willing. I'm not that handy, but I followed a YouTube video and did the batteries on my wife's '21 Wrangler in 45 minutes. I'll do the same with mine in the next couple of weekends.

I would guess the battery is tucked below more due to under hood space, design, packaging and the cost of manufacturing. Better manufacturing cost wise to tuck it down there than redesign a lot of other things in the vehicle just to get it up next to the other battery or to make space in some other accessible location to save a half hour of time changing it out when it goes out.

 

[JTdiRtyD]

I would guess the battery is tucked below more due to under hood space, design, packaging and the cost of manufacturing. Better manufacturing cost wise to tuck it down there than redesign a lot of other things in the vehicle just to get it up next to the other battery or to make space in some other accessible location to save a half hour of time changing it out when it goes out.

The diesel it's super easy to get to, just pull the main battery, pop off a cover and theres the aux. Gassers are more difficult from what I've read and have to be accessed through the wheel well. Not sure why the two are different since everything is still the same physical location.

 

[Proximo]

@woodthecrab did you fix your problem? What's the dash read when you have remote start failure?

 

[woodthecrab]

New batteries last weekend. No problems!

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