🪛 Key Fob 101 - Know thy JT key fob 🪛

[Threedom]

This awesome, thanks for sharing. I don't need a new battery yet but wondered how to start the jt once the battery dies

@JTBurns

Exactly as mentioned here if the fob battery dies..... https://www.jeepgladiatorforum.com/...inside-disassembly-and-more.55004/post-901704

Just know that each time you turn off the JT/JL until you change the fob battery, you will have to do the dance mentioned in that post...

Important ... Remember, with that dead fob battery.... when you exit the vehicle, do not lock the JT/JL up by pressing the door lock button on the door.

Get out of the JT/JL and lock it with the key, using the key.

IF, you use the door lock button to lock and set the system alarm, when you come back later to the JT/JL and use your key to open the door..... the door will unlock and the alarm will sound/honk honk honk..

By the way, it is prudent to keep a spare, CR2450 battery on hand. They are fairly inexpensive.

 

[Threedom]

Faraday Pouch - Why own/use one....
You might want to carefully read the following:

Features like keyless entry and keyless start are extremely convenient for drivers, as you can unlock your vehicle and hit the ignition without having to get the key out of your pocket....

However, this technology can also leave you vulnerable to sophisticated thieves: they are known to use relay devices (see graphic below) to copy a fob's signal, allowing them to drive off with your car without leaving a trace. These relay devices can be had for $30+- and are easy to acquire and easy to use...

What is a Faraday pouch?

A Faraday pouch or bag (aka: RFID bag) is lined with a material, frequently copper based, that contains the RF signal transmitted by a vehicle's fob. The material absorbs and redistributes electronic signals from the fob, not allowing the signals to escape.

It’s this signal that tells your JT/JL that the fob is nearby and allows the vehicle to be unlocked without pushing a button on the key fob.

So in a nutshell, a Faraday Pouch/bag blocks all radio signals ranging from Wi-Fi and Bluetooth to RFID (used by credit cards and car fobs) and GPS.

In closing..... DO highly consider buying a Faraday Pouch/Bag ....and do put it to use. Faraday Bags are inexpensive.

Do read the Faraday Bag reviews/shop around, before you buy, as not all Faraday Bags are durable and can be known to fail..

Important:

Periodically check/test your Faraday Bag to be sure it is up not damaged and not serviceable.

Day to day use can damage the bag lining with the result that the signal blocking ability is compromised..

How to test that Faraday Bag .... Place a fob in the Faraday Bag... close up the bag properly and then squeeze the bag so that it initiates a button push on the fob inside.

If, when doing the fob button push, your JT/JL responds, do know that your Faraday Bag needs replacement as it is not blocking radio signals as it is suppose to do.

​

YES, a Farady Pouch/Bag is a defense against Relay Hacking....​

 

[redriderjf87]

@Kevin_D

Both circuit board and RFID chip are in the buttonless factory fob.

Here is a pic of a buttonless factory fob opened up.... the pieces..

Thanks, I was curious since that's what mine is.

No battery in that case if I'm seeing right for the buttonless?

And either way I was assuming the RFID to start the vehicle is passive and doesn't require fob battery to start the jeep?
Edit I'm seeing the other post now with that info

 

[Threedom]

Thanks, I was curious since that's what mine is.

No battery in that case if I'm seeing right for the buttonless?

And either way I was assuming the RFID to start the vehicle is passive and doesn't require fob battery to start the jeep?
Edit I'm seeing the other post now with that info

@redriderjf87

All JT/JL fobs have a CR2450 battery, a circuit board and an RFID chip in them.

Regarding the Fob Circuit Board and CR2450 Battery:
With the programmed circuit board and attached healthy fob battery.... in simple terms, the fob talks to the JT/JL.... the vehicle then knows it is ok to start and run, turn on and off, and the vehicle is allowed to run.... and deals with the vehicle alarm.., etc.. You do not actually need the RFID chip in the mix/ in the fob...

Without the 3V fob battery to power the circuit board, (programmed to your specific JT/JL) the fob would not be able to communicate with the JT/JL.. so the vehicle would not know that your programmed fob was present and your JT/JL could not be started...... It could not be started even though there is an RFID chip in the fob. SO, without the fob battery or if the fob battery is depleted... you need to know the following in order to start/drive the vehicle..

With a dead fob battery, you take the fob and while holding the brake pedal down, you press firmly, the end of the fob that holds the RFID chip to the start button...(the fob end opposite of the panic button ) the RFID chip is then noted by the JT/JL and the JT/JL will start. ( Important: Remember, with that dead fob battery.... when you exit the vehicle, do not lock the JT/JL up by pressing the door lock button on the door. ) Get out of the JT/JL and lock it with the key, using the key.
IF, you use the door lock button to lock and set the system alarm, when you come back later to the JT/JL and use your key to open the door..... the door will unlock and the alarm will sound/honk honk honk..

 

[Threedom]

Gotcha thanks.

I guess I'm still a little confused as to how pressing the end of the fob with the RFID works with the battery dead, unless the RFID is being used passively (I'm thinking like my badge scan at work where the badge has to basically touch the reader in my case).

And then the battery otherwise just amplifies that signal to communicate farther away?

@redriderjf87

Remember... the JT/JL's RFID chip and the programmed circuit board can be separated... they do not need to work together necessarily... Read over what I posted earlier..

There's lots of info on the internet in regard to RFID technology..

To be honest, much of what's out of there is above my pay grade so to speak... I will settle with
knowing how my fob works in regard to my Jeep. IF you are thirsty for more RFID related info....

Fobs, RFID chip badges and such..
A starting point for your research on this topic...

RFID devices are categorized by the frequency band in which it operates. Low, High or Ultra-high frequency. However, there are two major categories of RFID systems – Active and Passive. Battery and antenna involvement play a part in this.

 

[redriderjf87]

@redriderjf87

Remember... the JT/JL's RFID chip and the programmed circuit board can be separated... they do not need to work together necessarily... Read over what I posted earlier..

There's lots of info on the internet in regard to RFID technology..

To be honest, much of what's out of there is above my pay grade so to speak... I will settle with
knowing how my fob works in regard to my Jeep. IF you are thirsty for more RFID related info....

Fobs, RFID chip badges and such..
A starting point for your research on this topic...

RFID devices are categorized by the frequency band in which it operates. Low, High or Ultra-high frequency. However, there are two major categories of RFID systems – Active and Passive. Battery and antenna involvement play a part in this.

Thanks, yeah for sure. I was mainly wondering if the jeep fob was active or passive RFID. I'll research further as it seems like some combination based on whether or not there's battery power.

Good to know there's an easy workaround if the fob battery dies which was my main concern, thanks for that info also.

 

[Threedom]

Amazing how tiny my Threedom fob feels in my pocket. Getting the RFID chip out was a job & a half. Be patient cutting the plastic around it. Took me about 30 minutes for the chip removal, but worth every minute.

@JustDave

You like that Threedom fob now... ... and, I can assure you that as the days go by, you will be saying to yourself .... Geeez, why didn't I get this darn Threedom fob sooner..

Thanks for your purchase of a Threedom fob.

About the RFID chip removal process... Dependent on the individual factory JL/JT fob, the RFID chip removal can be very easy or a process that takes patience and is slightly more involved. Some RFID chips are more firmly secured in the fob then others are.

You chose to cut the plastic around the RFID chip in order to facilitate removing the chip.. this approach is a way but we suggest that guys/gals try other approaches first.. But... even though you cut a bit of plastic, you still could still easily transition back to that factory fob and place the RFID chip back in that factory fob, RFID slot if you desired to..

A few ways other's have told us, in regard to removing RFID chip from the factory fob...

• Small cut of chip holder wall and then prying that wall away from the chip, enough that a small flat/very thin tip screwdriver blade can be inserted to gently pry up the chip.
• Removed the circuit board and all from the factory fob and then placing the casing with the inserted chip in a hot cup of water. Wait a few minutes then carefully insert a very thin flat tip screwdriver into the crevice that is between the chip and the chip holder and then pry the chip up and out. Warm plastic tends to give easier. (The RFID chip is sealed/is water proof... Threedom say's do this approach at your own risk)
• Take circuit board with battery out of the factory fob and then firmly.. very firmly, keep slamming the fob casing with the chip in it's holder, face down on a hard surface. This approach will hopefully, see the chip forcefully falling out.
• Take a very thin blade screwdriver and place the thin tip in the crevice between the chip and the chip holding box. Now, with a small hammer tap on the handle of the screwdriver, slowly driving the tip of the blade down. Once down a bit, you can lean the screwdriver blade a bit and the sidewall of the holder will give a bit.. now, start to pry the chip up and out..

So, these are just a few ways we have heard in regard to the removal of the RFID chip. We also show the RFID chip being removed in our factory fob disassembly video found here.

Do know that the RFID chip is quite sturdy. It will handle prying and pressing on it, but will not handle you piercing it or cutting into it deeply. We have had no reports of a guy or gal destroying their RFID chip when removing it, but do be careful when removing the RFID chip.

Note: If you wish to test your RFID chip after you remove it from the fob.... Take the chip to your unlocked JL/JT and with your foot pressing firmly on the brake pedal, push that little RFID chip firmly against the started button until the starter button depresses.. The JT/JL now starting, means your RFID chip is aok/healthy.

 

[Gatorized]

Faraday Pouch - Why own/use one....
You might want to carefully read the following:

Features like keyless entry and keyless start are extremely convenient for drivers, as you can unlock your vehicle and hit the ignition without having to get the key out of your pocket....

However, this technology can also leave you vulnerable to sophisticated thieves: they are known to use relay devices (see graphic below) to copy a fob's signal, allowing them to drive off with your car without leaving a trace. These relay devices can be had for $30+- and are easy to acquire and easy to use...

What is a Faraday pouch?

A Faraday pouch or bag (aka: RFID bag) is lined with a material, frequently copper based, that contains the RF signal transmitted by a vehicle's fob. The material absorbs and redistributes electronic signals from the fob, not allowing the signals to escape.

It’s this signal that tells your JT/JL that the fob is nearby and allows the vehicle to be unlocked without pushing a button on the key fob.

So in a nutshell, a Faraday Pouch/bag blocks all radio signals ranging from Wi-Fi and Bluetooth to RFID (used by credit cards and car fobs) and GPS.

In closing..... DO highly consider buying a Faraday Pouch/Bag ....and do put it to use. Faraday Bags are inexpensive.

Do read the Faraday Bag reviews/shop around, before you buy, as not all Faraday Bags are durable and can be known to fail..

Important:

Periodically check/test your Faraday Bag to be sure it is up not damaged and not serviceable.

Day to day use can damage the bag lining with the result that the signal blocking ability is compromised..

How to test that Faraday Bag .... Place a fob in the Faraday Bag... close up the bag properly and then squeeze the bag so that it initiates a button push on the fob inside.

If, when doing the fob button push, your JT/JL responds, do know that your Faraday Bag needs replacement as it is not blocking radio signals as it is suppose to do.

​

YES, a Farady Pouch/Bag is a defense against Relay Hacking....​

Interesting that a device to steal your car is cheap at ~$30, but it costs $100+ to replace a key… and only a dealer can program it.

 

[Threedom]

Voted BEST JT/JL Factory Fob carrier in 2021

Zeuss Model 3128 with heavy duty casters..

 

[Nuddot]

@JustDave

You like that Threedom fob now... ... and, I can assure you that as the days go by, you will be saying to yourself .... Geeez, why didn't I get this darn Threedom fob sooner..

Thanks for your purchase of a Threedom fob.

About the RFID chip removal process... Dependent on the individual factory JL/JT fob, the RFID chip removal can be very easy or a process that takes patience and is slightly more involved. Some RFID chips are more firmly secured in the fob then others are.

You chose to cut the plastic around the RFID chip in order to facilitate removing the chip.. this approach is a way but we suggest that guys/gals try other approaches first.. But... even though you cut a bit of plastic, you still could still easily transition back to that factory fob and place the RFID chip back in that factory fob, RFID slot if you desired to..

A few ways other's have told us, in regard to removing RFID chip from the factory fob...

• Small cut of chip holder wall and then prying that wall away from the chip, enough that a small flat/very thin tip screwdriver blade can be inserted to gently pry up the chip.
• Removed the circuit board and all from the factory fob and then placing the casing with the inserted chip in a hot cup of water. Wait a few minutes then carefully insert a very thin flat tip screwdriver into the crevice that is between the chip and the chip holder and then pry the chip up and out. Warm plastic tends to give easier. (The RFID chip is sealed/is water proof... Threedom say's do this approach at your own risk)
• Take circuit board with battery out of the factory fob and then firmly.. very firmly, keep slamming the fob casing with the chip in it's holder, face down on a hard surface. This approach will hopefully, see the chip forcefully falling out.
• Take a very thin blade screwdriver and place the thin tip in the crevice between the chip and the chip holding box. Now, with a small hammer tap on the handle of the screwdriver, slowly driving the tip of the blade down. Once down a bit, you can lean the screwdriver blade a bit and the sidewall of the holder will give a bit.. now, start to pry the chip up and out..

So, these are just a few ways we have heard in regard to the removal of the RFID chip. We also show the RFID chip being removed in our factory fob disassembly video found here.

Do know that the RFID chip is quite sturdy. It will handle prying and pressing on it, but will not handle you piercing it or cutting into it deeply. We have had no reports of a guy or gal destroying their RFID chip when removing it, but do be careful when removing the RFID chip.

Note: If you wish to test your RFID chip after you remove it from the fob.... Take the chip to your unlocked JL/JT and with your foot pressing firmly on the brake pedal, push that little RFID chip firmly against the started button until the starter button depresses.. The JT/JL now starting, means your RFID chip is aok/healthy.

I changed mine over to a Threedom fob the day I picked up my new JT. I love the new fob. I, however lacked the patience for removing the RFID using the above methods. Since I do not plan to change back (and can purchase a replacement fob if I do), I went with the factory fob destruction method of removal. Keep making great products!

 

[Threedom]

I changed mine over to a Threedom fob the day I picked up my new JT. I love the new fob. I, however lacked the patience for removing the RFID using the above methods. Since I do not plan to change back (and can purchase a replacement fob if I do), I went with the factory fob destruction method of removal. Keep making great products!

@Nuddot

Thanks for your purchase of a Threedom fob.. The Threedom Team knew you and other's would love it!

YES, we are continuing to make product offerings for the JT and JL...

For those that "lack the patience" to deal with the RFID chip removal..

There is another way so to speak...

You can disassemble the factory fob and leave the RFID chip alone/leave it in it's holder in the fob casing/shell.

Just take the circuit board, battery, key with the roll pin, and with those, easily easily assemble your Threedom fob.

That assembled Threedom fob will be all you need to have/use for your day to day use of your JT/JL. You do not need the RFID chip in the JL/JT fob. All you need is a programmed for your vehicle circuit board and a healthy CR2045 battery inside the Threedom fob and your key.

You do want to have that RFID chip handy though, as if your fob battery dies, the fob gets wet and no longer works, etc. you will need the RFID chip so you can start your JT/JL and get home.. See my post earlier in this thread showing / explaining how to start with the RFID alone... Read this post over carefully.

So... with that said, you can without issue, use the Threedom fob without having the RFID chip in it.... but you would want to take that disassembled factory JT/JL fob with the RFID chip in it and stash it well / hide it well, in the vehicle so that if/when that day comes, that you need to use the RFID chip to start the vehicle, that you will have the RFID chip with you/with the vehicle.

Threedom encourages guy/gals to move the RFID chip to their new Threedom fob when they assemble it but again, this work around lets call it, can be used. You decide whether this work around is a way to go for you.

For sure, there are many that do not feel comfortable trying to / dealing with, the removal of the RFID chip from the factory fob.. This work around is A WAY for them to not deal with the RFID chip and still enjoy having/using a terrific Threedom fob...

 

[Threedom]

IF you have any questions, ask away...

IF you have something to say regarding the disassembly, etc., let's hear it..
Help thy fellow JL /JT owner..

 

[Threedom]

Reminder... Order some back-up CR2450 Fob batteries...

 

[Threedom]

For those that have not had their factory fob apart .... here is a very clear picture of IT...a part.

Note the size of the circuit board.... seeing the size of the circuit board, show's you WHY.... why, the factory fob is so big.

Click on pic to enlarge

 

[Threedom]

Changing the CR2450 battery in a JT / JL factory key fob..

I'd like to personally thank Mopar for doing this video ... now I don't have to do one to post in this thread..

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