Push to start not working first try. Second try works fine.

[Nevaehd]

Has anyone experienced any issues with their JL push to start not wanting to work on the first try. Seems to be happening mainly in the morning after the jeep sits over night, or if it sits for a few hours. Never had any issues before. No cranking of the starter. I have power but it just won’t start. Second push to start works fine. Research says Aux battery so that was going to be my first step.

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[Heimkehr]

Depending on the age of the vehicle and/or the batteries, the wonky Start button functioning may indeed be linked to one or both batteries approaching the end of their practical service life.

That said, once in a blue moon I'll catch myself pressing the brake pedal too lightly, just enough to disallow an engine start, but the dash lights and self-diagnostics (evident via the needle sweeps) will illuminate and cycle as usual.

 

[garyji]

What James said. What year JL and how old are the batteries??

G.

 

[Nevaehd]

it’s a 2018 JLU with 80,000 miles. I’ve been more aware of pushing the break harder but it seems to still keep doing it every morning

 

[Heimkehr]

it’s a 2018 JLU with 80,000 miles. I’ve been more aware of pushing the break harder but it seems to still keep doing it every morning

If the batteries are the originals, you might consider replacing them as a prophylactic measure. Just a thought.

 

[Erievon]

I'm pretty sure this means one of your batteries failed the battery test, but the other still has enough juice to start the jeep. I'm willing to bet your ESS doesn't work either.

 

[garyji]

2018 on original Batteries?? Definitely start there. Non-eTorque?? Change em both ASAP.

G.

 

[wjcubellis]

Has anyone experienced any issues with their JL push to start not wanting to work on the first try. Seems to be happening mainly in the morning after the jeep sits over night, or if it sits for a few hours. Never had any issues before. No cranking of the starter. I have power but it just won’t start. Second push to start works fine. Research says Aux battery so that was going to be my first step.

Happened to me. One year old , original battery , 2024 2-door Rubicon. Drove to the beach, didn't use it for 6 days. When I went to start it this morning exactly what you described happened. Has happened to me once before when it was in the garage for a few days without using it. It's a bit disconcerting on a one year old battery. Both times it did start after several attempts. Thinking maybe I should have the battery tested..

 

[lowmpg]

Don't overlook the key fob battery.

 

[20-Willys]

I think this is a normal occurance when the ESS batteries fail. It attempts the normal method to start and when that fails a bypass is invoked which switches to the main battery for everything. It's best to replace both batteries together.

 

[Heimkehr]

Don't overlook the key fob battery.

A good point. The batteries in our two proximity fobs have a noticeably shorter service life than do the batteries in our other, actual key fobs, which function solely when their Lock/Unlock buttons are pressed.

I think this is a normal occurance when the ESS batteries fail. It attempts the normal method to start and when that fails a bypass is invoked which switches to the main battery for everything.

Wouldn't the main battery be used for cold starts? The ESS battery is exactly that: intended for warm restarts when the driver lifts his foot off the brake pedal.

 

[lowmpg]

A good point. The batteries in our two proximity fobs have a noticeably shorter service life than do the batteries in our other, actual key fobs, which function solely when their Lock/Unlock buttons are pressed.



Wouldn't the main battery be used for cold starts? The ESS battery is exactly that: intended for warm restarts when the driver lifts his foot off the brake pedal.

I can tell you my Jeep had a similar problem, wouldn't start on the first push. Replaced the key battery, worked fine ever since.

 

[AndySpill]

Has anyone experienced any issues with their JL push to start not wanting to work on the first try. Seems to be happening mainly in the morning after the jeep sits over night, or if it sits for a few hours. Never had any issues before. No cranking of the starter. I have power but it just won’t start. Second push to start works fine. Research says Aux battery so that was going to be my first step.

The dual AGM batttery JL will normally attempt to isolate the Aux battery for an instant when the operator attempts to cold crank the vehicle, so that this battery alone can be tested for voltage to see if it has adequate power to run ESS events.

The status of the ESS button in the dash does not change this startup procedure.

If the Aux battery has inadequate power the crank will fail, but subsequent attempts to crank will--provided you don't have an early 2018 that lacks TSB 18-092-19--be effected solely against the main battery, and if successful, turn the ESS off light (the "A" with a near circle surrounding it, and a slash through it) on in the dash.

Is this what is happening to your dash?

All subsequent cold cranks will still test the Aux battery but if it fails, repeat this procedure automatically trying the crank against the main battery, and if successful at getting just the main battery to crank the engine, keep this ESS off light illuminated in the dash.

When this light is on ESS events can't occur: this light having no connection to the ESS off button.

Not until the next cold crank in which an energized Aux battery is detected, if any, or the JL is tricked as per the below procedure, will this light in the dash shut off.

I would replace both batteries, or just the main battery and disconnect and bypass the Aux battery provided you are willing to not run ESS events.

Disconnecting and bypassing the Aux battery involves at minimum pulling Fuse 42 in the Power Distribution Center and removing the factory cable on the main battery's negative post that does NOT have as its other end the body ground on the passenger's front quarter panel. The end of that disconnected cable should be insulated. This disconnected cable at its distal end connects to the negative post of the Aux battery which pulling this cable off the main battery's negative post removes the Aux battery from the electrical schematic of the vehicle, no longer delivering or receiving charge.

Pulling Fuse 42 prevents the Aux battery from ever being isolated such that calls for it to exclusively provide power, either in ESS events, or the pre-crank test, now go to all available batteries, of which the aforementioned cable pull leaves you with just the one main battery.

It is recommended that you turn ESS off if you take this fuse and cable pull route. Expect the light in the dash to turn off with just a new main battery and the Fuse and cable pull as the pre crank test succeeds against solely the main battery, the vehicle none the wiser that it mistakenly tested the main battery given the fuse pull, unable to energize the normally clsoed relay that when energized (which requires an intact Fuse 42) separates the batteries.

Turning ESS off is recommended when eliminating the Aux battery from the vehcile's electric schematic, so as to not run ESS events against the main battery, it normally being spared during ESS events under the factory configuration, to bear the bulk of the cranking effort when ESS events terminate.

 

[RatZero]

Check the keyfob battery first, if you have the proximity package it will do two checks when you open the door. One to unlock and another right after that tells the vehicle to get ready to start. If the battery is weak, the first check passes but will occasionally fail the second. It's a security feature patch that got passed on from the Chargers and Challengers after they were getting key transmission codes stolen.

 

[AndySpill]

Check the keyfob battery first, if you have the proximity package it will do two checks when you open the door. One to unlock and another right after that tells the vehicle to get ready to start. If the battery is weak, the first check passes but will occasionally fail the second. It's a security feature patch that got passed on from the Chargers and Challengers after they were getting key transmission codes stolen.

Replacing the keyfob battery can do no harm. But the OPs description is consistent with an Aux battery on its way out, which will take the main battery with it over time as these two batteries are normally connected in parallel in the dual AGM battery JL.

OP, 3 years for battery replacement....it sounds like you should consider yourself lucky that you went twice as far...or is it a 2018 that has had battery replacements already???

Please, if keeping the Aux battery in the electrical schematic of the vehicle, do not solely replace just it. Replace both batteries or disconnect the Aux as per my prior post and just replace the main, turning ESS off with a button push or aftermarket tech to do it for you.

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