2018 JL wont start.

[technicallyanOldguy]

Okay my 2018 JL will not start. The key fob appears to be ok but, will not start the Jeep on it own or with either of 2 fobs pressed into the press to start button.
The interior lights are ok. The breaks appear stiff but no matter how hard you press them it will not start.
The panel does show press the break and start but that is it. It will not go into accessory mode. No power to radio etc. I checked the hood, door and seat belt for proper connections. All looks ok. Just no response when I press the start. The battery was replaced last year and is really good. The fuses were a little loose but all ok now. I was wondering if I remove the battery cables will it reset the system but cause other issues? Any thoughts?
Jessie

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[Rustynail11]

get the battery checked would be my next step

 

[Bill_P]

Try replacing the fob batteries. It's a cheap place to start and may be the issue if they are running on the original batteries.

 

[Rhinebeck01]

Okay my 2018 JL will not start. The key fob appears to be ok but, will not start the Jeep on it own or with either of 2 fobs pressed into the press to start button.
The interior lights are ok. The breaks appear stiff but no matter how hard you press them it will not start.
The panel does show press the break and start but that is it. It will not go into accessory mode. No power to radio etc. I checked the hood, door and seat belt for proper connections. All looks ok. Just no response when I press the start. The battery was replaced last year and is really good. The fuses were a little loose but all ok now. I was wondering if I remove the battery cables will it reset the system but cause other issues? Any thoughts?
Jessie

@technicallyanOldguy

I reached out to you in a private message.... in short though, this undoubtedly is the issue..

Your 2018 JL, built in early 2018 will not start or even try to start, if the Aux battery is depleted....

.......even if the Main battery is fully charged/healthy, it will not try to start. Forum search using the words TSB 18-092-19 completed (Power Control Update) to learn more about this.

I strongly suggest that you ASAP, replace your factory installed (in 2018) Aux battery.... and or bypass it. Load test the Main battery to be sure it is aok.... if not replace the Main battery also.

The Aux battery can be left bypassed forever should you want to do so. Just be sure to limit the use of ESS. Push the ESS button and then drive or buy an adjunct that in essence does that battery push for you.

Read here in regard to the H7 ... again H7 Main battery you will want to buy to replace your current Main battery.. https://www.jlwranglerforums.com/forum/threads/??-main-battery-replacement-talk-jl-jt.100534/

Should you decide to change out the Aux battery read here: https://www.jlwranglerforums.com/fo...ent-the-easy-way-pull-the-fender-flare.56807/

Read here: https://www.jlwranglerforums.com/forum/threads/jumperless-aux-battery-bypass.95945/

 

[aldo98229]

The battery was replaced last year and is really good. The fuses were a little loose but all ok now. I was wondering if I remove the battery cables will it reset the system but cause other issues? Any thoughts?
Jessie

Who replaced the battery? The dealer? If so, most likely they need to be replaced again.

The OE batteries are garbage.

 

[hoch]

Try replacing the fob batteries. It's a cheap place to start and may be the issue if they are running on the original batteries.

Fob battery has nothing to do with it. Even if the battery is completely dead, you can still start your Jeep. Just hold the fob (which holds the transponder chip) next to the push button start and it’ll fire up.

 

[2mnycars]

Our history...2019 JLU wouldn't start after sitting for a week. Tried the COSTCO recharging brick we had bought just in case. JLU wouldn't start. Called for road assist. Truck arrived. He had a large charging battery and he hooked up for about 10 minutes. Then the '19 JLU started. If I remember right it was the small auxiliary battery that was dead.

DaveL
Toronto

 

[Rhinebeck01]

Our history...2019 JLU wouldn't start after sitting for a week. Tried the COSTCO recharging brick we had bought just in case. JLU wouldn't start. Called for road assist. Truck arrived. He had a large charging battery and he hooked up for about 10 minutes. Then the '19 JLU started. If I remember right it was the small auxiliary battery that was dead.

DaveL
Toronto

Your 2019 will start on second attempt to start, when Aux battery is depleted and Main battery is aok.

Most 2018 JL's will not start at all if Aux battery is depleted, even if Main battery is aok. OP has a 2018 JL.

 

[Bill_P]

Fob battery has nothing to do with it. Even if the battery is completely dead, you can still start your Jeep. Just hold the fob (which holds the transponder chip) next to the push button start and it’ll fire up.

Mine didn't. I replaced the fob battery and it worked

 

[jludave]

Mine didn't. I replaced the fob battery and it worked

The JL is designed to start using the key fob even if the key fob battery is dead.

Per the owner's manual:

"Put the nose side of the key fob (side opposite of the Emergency Key) against the ENGINE START/STOP button and push to operate the ignition switch."

 

[Friday2322]

I'm surprised everyone with the 18 hasn't went in to get the update so this doesn't happen. Good luck, I hope it turns out to be something simple.

 

[Jebiruph]

Okay my 2018 JL will not start. The key fob appears to be ok but, will not start the Jeep on it own or with either of 2 fobs pressed into the press to start button.
The interior lights are ok. The breaks appear stiff but no matter how hard you press them it will not start. U
The panel does show press the break and start but that is it. It will not go into accessory mode. No power to radio etc. I checked the hood, door and seat belt for proper connections. All looks ok. Just no response when I press the start. The battery was replaced last year and is really good. The fuses were a little loose but all ok now. I was wondering if I remove the battery cables will it reset the system but cause other issues? Any thoughts?
Jessie

Others have posted an issue with the stiff brake pedal and have had to press down extra hard to trigger the switch.

 

[2mnycars]

Your 2019 will start on second attempt to start, when Aux battery is depleted and Main battery is aok.

Most 2018 JL's will not start at all if Aux battery is depleted, even if Main battery is aok. OP has a 2018 JL.

Thanks

It was flat dead. That was after about 7 days of sitting idle.

 

[technicallyanOldguy]

@technicallyanOldguy

I reached out to you in a private message.... in short though, this undoubtedly is the issue..

Your 2018 JL, built in early 2018 will not start or even try to start, if the Aux battery is depleted....

.......even if the Main battery is fully charged/healthy, it will not try to start. Forum search using the words TSB 18-092-19 completed (Power Control Update) to learn more about this.

I strongly suggest that you ASAP, replace your factory installed (in 2018) Aux battery.... and or bypass it. Load test the Main battery to be sure it is aok.... if not replace the Main battery also.

The Aux battery can be left bypassed forever should you want to do so. Just be sure to limit the use of ESS. Push the ESS button and then drive or buy an adjunct that in essence does that battery push for you.

Read here in regard to the H7 ... again H7 Main battery you will want to buy to replace your current Main battery.. https://www.jlwranglerforums.com/forum/threads/??-main-battery-replacement-talk-jl-jt.100534/

Should you decide to change out the Aux battery read here: https://www.jlwranglerforums.com/fo...ent-the-easy-way-pull-the-fender-flare.56807/

Read here: https://www.jlwranglerforums.com/forum/threads/jumperless-aux-battery-bypass.95945/

Thanks so much. I was going to post some info but, I hate redoing what others have already posted. The actual culprit was the primary battery. Replaced it and all is now ok. No warning lights and both the primary and secondary batteries are AMP appropriate in readings. Thanks so much.

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