Key FOB Not Detected on my JL Wrangler

wayoflife

wayoflife

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So, I've got a new problem on my 2018 Jeep JL Wrangler Rubicon Unlimited and it's in regards to the Key FOB. Just recently, my JL doesn't seem to want to recognize either of my 2 Key FOB's and I have verified that the batteries on both are good. What's weird is that the problem doesn't happen all the time. I can literally get in and start my Jeep without any problems and then Cindy could open her door, step out and then get a message on my EVIC saying that the Key FOB has left the vehicle. This in spite of the fact that I still have it. And then there are times when my Jeep doesn't detect it at all and I have to press the FOB on the start button to get the engine going. Any of you have this problem and if so, do you know of a fix for it?

Thanks for your help :)
 
Thinking outside a very obscure box here but…. Were you having this issue before or after you installed the blackout tail lights? As ridiculous as it may seem I’m just wondering if for some reason it’s disrupting something in the system. Outside if that I suppose it’s possible that the keyless system or anti theft system has got some gremlins popping up.
 
So, I was having this problem before the new lights but very intermittently. At the time, I had assumed my Key FOB battery was dying and so I just started using my other one. Again, the problem was intermittent so it not happening again left me to think it was all good. However, just recently, like within the last week or so, the problem has been more present. Almost like it has something to do with the cold. Anyway, I should note that the lights did come to mind as well and I did reinstall the factory ones just to make sure they weren't the cause. No go. I just did an update on my Tazer right now as well, just in case that was the issue. Of course, during the whole process, I never had a problem with the FOB. So annoying.
 
wayoflife said:
So, I was having this problem before the new lights but very intermittently. At the time, I had assumed my Key FOB battery was dying and so I just started using my other one. Again, the problem was intermittent so it not happening again left me to think it was all good. However, just recently, like within the last week or so, the problem has been more present. Almost like it has something to do with the cold. Anyway, I should note that the lights did come to mind as well and I did reinstall the factory ones just to make sure they weren't the cause. No go. I just did an update on my Tazer right now as well, just in case that was the issue. Of course, during the whole process, I never had a problem with the FOB. So annoying.
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Damn and here I was thinking I was being clever 🤣🤣🤣 that sounds really frustrating especially being that it’s so intermittent. The cold certainly makes sense… unless it also does it when y’all are down in the Vegas area. Push button starting is cool… until it does crap like this 🤦🏼‍♂️
 
RESURECTIONJK said:
Damn and here I was thinking I was being clever 🤣🤣🤣 that sounds really frustrating especially being that it’s so intermittent. The cold certainly makes sense… unless it also does it when y’all are down in the Vegas area. Push button starting is cool… until it does crap like this 🤦🏼‍♂️
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Honestly, I really hate the push button start and mainly because I knew something like this would happen someday. But yeah, the problem only seemed to start once we got back up to winter. Again, I went into our garage (front garage - much warmer) and all seems good. We went out for a quick drive in the snow this morning, back when it was like 25 out and had issued. Not sure why cold would cause things to go weird though. Maybe just a coincidence.
 
wayoflife said:
Honestly, I really hate the push button start and mainly because I knew something like this would happen someday. But yeah, the problem only seemed to start once we got back up to winter. Again, I went into our garage (front garage - much warmer) and all seems good. We went out for a quick drive in the snow this morning, back when it was like 25 out and had issued. Not sure why cold would cause things to go weird though. Maybe just a coincidence.
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Cuz jeep 🤣🤣🤣
 
wayoflife said:
So, I've got a new problem on my 2018 Jeep JL Wrangler Rubicon Unlimited and it's in regards to the Key FOB. Just recently, my JL doesn't seem to want to recognize either of my 2 Key FOB's and I have verified that the batteries on both are good. What's weird is that the problem doesn't happen all the time. I can literally get in and start my Jeep without any problems and then Cindy could open her door, step out and then get a message on my EVIC saying that the Key FOB has left the vehicle. This in spite of the fact that I still have it. And then there are times when my Jeep doesn't detect it at all and I have to press the FOB on the start button to get the engine going. Any of you have this problem and if so, do you know of a fix for it?

Thanks for your help :)
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Needs a new key fob battery
 
I've had this intermittently happen like 1 out of hundred starts or so. When it does, the next start corrects the issue so I've never looked into it much. Modern vehicle software sucks.
 
So I rebuilt a wrecked BRZ last year I bought at auction and it was missing a key, also a key fob with push button start. Different company and system, but I ended up learning a bit about dealing with replacing modules, and fighting with everything for months to get it back working

As you mentioned, and already know, things can get finicky when batteries start to get low’ish. I would start with replacing batteries all around (which it seems you did)

I think you are on the right path with removing the tail lights to eliminate any thoughts about interference between things. I’d look back at your maintenance log and anything electrical on it try and isolate it to verify if it helps or effects the issues.

Especially with intermittent issues I like to verify things multiple times. I see many people take something off, unplug, remove or change a setting and then go “that was it” or “that didn’t work” 5 minutes later. I like to run it for a bit (maybe a few days) to see what the results or outcomes are, and then even put it back to the way you have it not to verify that the issues come back again. Isolating and changing one thing or variable at a time helps a ton as well. Small steps

Next I would look into the doors and door handles. Most cars with the keyfob (even if they DONT have prox entry) still have antennas in the doors or door handles as the sheet metal and tub has a bit of a faraday cage effect on signals and electronics, so the manufacturers will have a small antenna receiver in the doors or door handles to help pickup where the key fobs are.

When the Jeeps working correctly and picking the fob up like it should, try to turn the ignition on and off multiple times and see if it will keep doing so while moving the keyfob out of the passenger compartment and outside of the tub/cab. Notice how it’ll stop picking it up usually when you cross the door threshold or out through the door window opening? I’m guessing it’s triangulating the position of the keyfob using the multiple antennas and this able to tell if it is a person in the seat trying to start it with the keyfob or not

I do remember people having trouble with the electrical harness with the JL’s and JT’s for the doors, something about when you pull them apart and plug them back together you’ll have some of the pins bend or push out the back side of the connector. (A Google search should lead you to posts from a forum). This of course can lead to all kinds of issues. From my experience with the antennas in the doors and handles, plus being a Jeep (Jet) that I know the doors have been on and off multiple times, I’m guessing, I can see this possibility being part of the problem as well. Or at least something to check out.

Lastly, on other push button start vehicles, I know in an emergency when your keyfob batteries die you are still able to start the vehicle by holding the keyfob upto the push button or right on the ignition column and it should recognize it. From what I gather it was something about the board in the fob, when powered by a battery ofc, would amplify the chips signal for the vehicle to pickup. But when dead, in an emergency, you could still hold it up and use that to start the vehicle. I’ve seen this in multiple owners manuals across diff brands

Hope some of the helps Eddie!
 
my 2018 has started giving the "Key Fob has left the Vehicle" while driving.

I replaced the battery in the fob but still getting the message.

At this point I hope it doesn't leave me stranded... I miss having a no frills "dumb" key
 
wayoflife said:
Honestly, I really hate the push button start and mainly because I knew something like this would happen someday. But yeah, the problem only seemed to start once we got back up to winter. Again, I went into our garage (front garage - much warmer) and all seems good. We went out for a quick drive in the snow this morning, back when it was like 25 out and had issued. Not sure why cold would cause things to go weird though. Maybe just a coincidence.
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Mine has acted up when it is really cold, as well. But not to the extreme you are experiencing. Batteries rectified mine.
 
I appreciate you guys chiming in on this. Of course, if you can believe it, I haven't had a problem with the Key FOB since making this post. Figures. Before this post, it was happening 1 in 4 tries LOL
 
Jet is just pissed cuz Pippi and the JT have been getting all the attention. He’s feeling like the weird middle kid that gets told it’s stilled loved but only kind of.
 
I had the same issue with our durango. It would get better when I replaced the batteries but only with quality brands. Cheap batteries (harbor freight, ikea, etc.) would not fix it. It still did it intermittently until we traded it in. Also it did have proximity entry as well so maybe the post about door handle antennas is going somewhere.
 
Maybe the door wire harness is loose? I’m probably not remembering correctly but I recall that when the doors are off and it’s locked it doesn’t recognize the fob unless you touch the start button. So maybe there’s some correlation there.
 
LOL - man, I honestly don't know what the deal is. I swear, the Key FOB was acting up like crazy but now, it's working every time. I rally hate all this technology in my Jeeps.
 
Mike Pierson said:
Maybe the door wire harness is loose? I’m probably not remembering correctly but I recall that when the doors are off and it’s locked it doesn’t recognize the fob unless you touch the start button. So maybe there’s some correlation there.
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Mine doesn't give a shit if the doors are on or not
 
believe it or not , cell phones will impact the key in a big way. we have issue calls all the time about it . If I have my key for the gladiator in the same pocket as my phone I can't open the doors. keys sitting in the console with the phone and it wont detect the key. We have also had issues where parked in certain spots with large amounts of wifi interference , won't detect key push it forward 2 feet and it works. We get calls all the time from a grocery store up the road and every time the vehicle is always in the same place in the parking lot. really weird.
 
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