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[News]
Locked Your Keys In The Car? Get Out Your Cell Phone

Louis E. Frenzel
September 11, 2006

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There has been a rumor going around in one of those dreadful e-mails that your friends and co-workers feel compelled to forward to you all the time. If you lock your keys in your car and you have a remote keyless entry system, you can get outside help to open the car if you have your cell phone with you. Just call someone that has a duplicate key fob that will open your car. Then, hold you cell phone near the door lock and have the person with the key fob call you back. The person with the key fob should then put the key near their phone and push the unlock button. The door should open.

I was skeptical, to say the least, about this rumor, and was about to dismiss it as one more Internet hoax. But I thought I better try it out first. Well, low and behold, it works. I tried it with both GSM and cdma cell phones, and it reliably opens (and relocks) the car.

I have been racking my brain for days about how this works. Two or more different wireless technologies are involved. I even used a 2.4 GHz cordless phone to make the call. The remote keyless entry usually uses on-off-keying (OOK), a form of ASK, to modulate a 315 MHz carrier with the correct serial digital code. Somehow the calling phone picks up this information and transmits it to the receiving cell phone, which then magically retransmits it to the door lock receiver in the car? Yeah, right.

All I can think of is that the digital code from the key fob modulates the sending phone and the receiving phone subsequently picks it up. But how does it transmit the code to the lock receiver in the car? Does the 315 MHz signal ride on the cell phone carrier some how? I thought I was a pretty good wireless guy, but this one baffles me.

If you have any thoughts to share on this, drop me a line at lfrenzel@penton.com. I’ll be sure to pass the word on to the others here next month.





[Reader Comments]
Locked Your Keys In The Car? Get Out Your Cell Phone

Name (required):efgre
- Submitted On: July 19, 2008
av av

Vijay
- Submitted On: July 12, 2008
BS you are idiots. This is not a topic to be discussed this full length. Pure BS

ÑemaBoy
- Submitted On: June 25, 2008
what a bunch of idiots if you think this works.

your mom
- Submitted On: May 16, 2008
Tell us what you think - post your comments here.

your mom
- Submitted On: May 16, 2008
im emo and icut myself

your mom
- Submitted On: May 16, 2008
im emo and icut myself

GGD
- Submitted On: April 8, 2008
what is key fob!! http://www.myfinanceadvisory.com/

paul
- Submitted On: April 8, 2008
Use www.cellplandepot.com to Get Out of your cell phone contract and not your car!

dawood
- Submitted On: March 23, 2008
Tell us what you think - post your comments here.i want on my phen that i can opin cars dors

ojo
- Submitted On: March 23, 2008
i tried it...it works my dear friends...i used 2 motos

bob
- Submitted On: February 1, 2008
IT DOES NOT WORK --and if you have managed to "GET IT TO WORK" then you are still within the range of your keyfob/remote/transmitter. Your mobile has a microphone - the microphone is like speaker in reverse look inside a hi-fi speaker for an example) when you talk you create a sound wave ..the speaker picks it up and turns the vibrations into an electrical signal. the electrical signal is then transmitted by your phone. at the other end the reverse happens the transmitted signal is recieved and converted back into an electrical signal..the electrical signal is then sent to your speaker on your phone (think of it like the track from you CD getting sent to your hifi speakers)that signal causes the speaker to vibrate and generates a sound wave ..that you can hear.

Can you hear the signal from your key fob? Does your keyfob make a sound?

NO is doesn't therefore it is not generating a sound wave, therefore the microphone cannot pick it up and cannot turn it into a signal that it can generate and send!...how hard is that to comprehend?

Name (required):jimmy james
- Submitted On: January 23, 2008
how to use your cell phone? dial: 1.888.4.ONSTAR

nsht
- Submitted On: November 8, 2007
Tell us what you think - post your comments here.

nsht
- Submitted On: November 8, 2007
somebody call me, I need to unlocked my cell phone!

Pip
- Submitted On: September 12, 2007
Tell us what you think - post your comments here.

kareem
- Submitted On: August 5, 2007
I just texted my cars rego number to myself and the car unlocked - amazing..

swines
- Submitted On: July 30, 2007
Just try it :l

Name (required):Waqqar
- Submitted On: July 17, 2007
hello

Waqqar
- Submitted On: July 17, 2007
Although i have not tried this but i still dont think it is possible

Name (required):Kegger
- Submitted On: July 15, 2007
To Regis Philbin, Hey I'll have to try that, what was your moms number again?

calming_insanity
- Submitted On: July 13, 2007
Explain this...all i have to say.

http://youtube.com/watch?v=cmIGT0IrO_0

Regis Philbin
- Submitted On: May 12, 2007
This girl called me once, held the phone up to her pussy and I ejaculated 400 miles away! Try it, it works!

Blofield
- Submitted On: May 9, 2007
It works on 3G video phones. If you show your car its key, it will unlock the doors for you.

bijay
- Submitted On: May 1, 2007
hitachi mobile sim unlock key

Yoda
- Submitted On: April 25, 2007
BS. That's all i can say, nothing else, just BS

Yugnaisa
- Submitted On: April 23, 2007
So which izzit? Work or doesn't? Well i guess i'll jz hav to try it out myself...

Bob
- Submitted On: April 12, 2007
Of course it works. This has been in use since the 1400's. Columbus used it on his ship.

D~LuX
- Submitted On: March 27, 2007
that shit dont work you stupid ass motha fuckas..quit sayin it does..fuckin clowns

Whitney
- Submitted On: March 23, 2007
I just called my sister and told her to do it and it actually worked! this thing is amazing!

Johnny Drama
- Submitted On: March 23, 2007
It didn't open my care door, but it did make me tinkle a little.

CJ
- Submitted On: March 23, 2007
It isn't not funny. this werks!!!

ANDRICKO
- Submitted On: March 17, 2007
good idea for car thieves

Ben
- Submitted On: March 3, 2007
Try a baluns on the receiving side of the experiment. Works every time.

dede
- Submitted On: February 14, 2007
i just looked like an idiot in front of my work mates doesnt work!

daniel
- Submitted On: February 14, 2007
all you wankers baggin it...try it first..cos it WORKS..you losers....

Chris
- Submitted On: February 12, 2007
Shut up all of you... IT WORKS Just try it out morons

Name (required):
- Submitted On: January 24, 2007
Tried it, didn't work. Honda and MOTO phone

skyflyrr
- Submitted On: December 13, 2006
The reaching inside the car to unlock the door is just as good as, no actually better since that explanation actually unlocks the car door, than my explanation above.

Jake
- Submitted On: December 11, 2006
This does seem pretty interesting, but it probably doesn't work. Unless your remote sends out ultrasonic or some other type of sound wave to unlock your car, then it might be picked up by the cellphone mike and it maybe even reproduced by the speaker. However, I think that most remotes use infared (which is light). Please correct me if I am wrong.

John
- Submitted On: November 24, 2006
Troll. Key fobs are RF. Cell phones do not "repeat" RF.

Andy
- Submitted On: November 22, 2006
I'm a skeptic, so i tried something else just as unlikely to work. I rolled the drivers window down, then stood beside the car and made a call on my cell phone. Believe it or not, while I was on the phone, i was able to reach INSIDE the car and unlock the door. You'll have to try it yourself if you don't believe me. IT WORKS!

I like cheese
- Submitted On: November 22, 2006
Ponder this.... Assume all RF waves could be transmitted over cell networks. If you called a bud on your cell, and you both happened to be near people on 900Mhz cordless phones (which are constantly interfering w/ each other) then the two cordless users could pick up each others' conversations, right? Total BS.

semi intelligent human
- Submitted On: November 21, 2006
Did you think to move out of range of the transmitter? Idiot

Name (required):
- Submitted On: November 21, 2006
what is key fob

viettel.com
- Submitted On: November 19, 2006
I tried it myself, but it didn't work, and I do believe that some lucky or crazy individual out there able to crank it open. The only explanation for this phenomenon is such that the modulated signal did pack along w/ your voice and on the other side, some how the 3r, 5th, ect harmonic able to produce the very near carrier frequency of those remote and bingo, magical does happen! amen!

Justin Nguyen viettel.com

ruko
- Submitted On: November 18, 2006
This is a REAL LOAD of internet CRAP

Malengelo
- Submitted On: November 14, 2006
I tried it and couldn't get a reliable result. Opel and Renault couldn't be opened by my Sony-Ericsson phone. Besides the shame I had in front of my colleagues killed me.

Pimp Juice
- Submitted On: November 9, 2006
Works for Hondas and Moto phones.

Flod
- Submitted On: November 8, 2006
http://www.snopes.com/autos/techno/keyless.asp

czar
- Submitted On: November 8, 2006
Most of you people have no idea how electronics or radio works.

Glitter wrote: "... the car remote is a 315 MHz then a cell phone could repeat a signal at that frequency since cell phones are operating at 900 MHz or higher..."

My response: The fact that one device's frequency is higher than the other's does not mean one can carry the other's signal. How'd you learn this?

He goes on: "hold the cell phone near the lock, which is the receiver" My response: The door lock is NOT the receiver!

And this tells it all: "Although I haven't tried any of this ...

"just looking good on paper ... " No, no it doesn't.

Name (required):Jimbo
- Submitted On: November 5, 2006
This *DOES* work. I was thinking what would happen if you phone the car whist it was being driven and attempt to perform one of the other features the key fob is able to perform. I.e. open the boot. I guess it depends how close the phone is to the car's radio receiver.

Djackson
- Submitted On: October 30, 2006
yes the article here is 100% TRUE phone a vauxhall garage or lexus,bmw or any car with a remote works. Read you are safe as a duplicate is needed of your fob not any remote works with the same car. scary but saves money and time

Name (required):Jeff
- Submitted On: October 25, 2006
I did the same thing with my ATM card. Held my phone beside the ATM while my Girlfriend swiped it across her phone at home. (No, not really)

Kiser Sosa
- Submitted On: October 19, 2006
I think you guys miss the point of Bob's comments, a cell phone does not pick up electro maganetic frequecy's through the microphone, if if did, the cell phone would be useless due to the enormous amount of EMF signals flying throuh the air at any point in time.

A microphone wants to take varying pressure waves in the air and convert them into varying electrical signals. They key fob does not vary air pressure, so, the microphone would not pick up anything to convert and trasmit

Name (required): Glitter
- Submitted On: October 10, 2006
Bob, you might not be as full as BS as you think ... if the car remote is a 315 MHz then a cell phone could repeat a signal at that frequency since cell phones are operating at 900 MHz or higher. The instructions are to hold the cell phone near the lock, which is the receiver - the cell phone simply functions as a repeater in the "wireless network". It doesn't need to know the sequence, just repeats the sequence from the key fob which is sequenced to the car lock.

If the above is true, then this should also work with a land line cordless phone (the older models are 900 Mhz so can likely transmit a 315 Mhz signal) ... which is great if you've locked the cell phone in the car along with your keys!

Although I haven't tried any of this ... just looking good on paper ...

jason
- Submitted On: October 7, 2006
I tryed it and it does work, after about 5 times of trying that is! but there is also a special software that you can put on most new mobile telephones that atcually opens your car door, you have to have the unique fob ID number from your service booklet!

Goodgod
- Submitted On: October 7, 2006
You have a cheap car!:)

Karl
- Submitted On: October 6, 2006
not so sure about the car thing but i know you can increase the range of your remote unlocking fob if you hold it to your head, saw it on TV an tested it for myself an it worked.

Bob
- Submitted On: October 2, 2006
You guys do know my post was full of BS don't you?

Ryan Bowlby
- Submitted On: October 2, 2006
Well an algorithm is synced between the two devices so storing it would not work because the code being transmitted is based on the algorithm and changes everytime. Kinda like RSA secure ids I guess.

Jimmy Jones
- Submitted On: October 1, 2006
fortunately, my car came with a mechanism to prevent me from locking the keys inside. The driver side never locks until u actually take the keys out n lock it using either d remote or key. VW 2005. so from inside, if u press d lock on d door, all doors lock except driver side and if u use remote from inside, nothing happens until u get out and press it. The only caveat is if my dumbass purposely lock d keys in the trunk. Then I'll want to verify or testify rather to this hack of cellphone "proofs"

Jack Stapleton
- Submitted On: October 1, 2006
So does that mean you can tape record it as well? Then put it on your Ipod and youll never need your keys to open the door? Then how about store a million of these codes on your Ipod then just walk around parking lots looting?

Infiknight
- Submitted On: September 29, 2006
This does work. I've just tested it with the key being WELL out of range. If you cant do the math behind it before you talk crap about it then there's little point in making yourself look so clever.

Bob
- Submitted On: September 29, 2006
The reason it works is that the key FOB transmits a quadrate modulation scheme of digital code which can ride as a sub carrier on the cell phone signal which than re modulates the receiving phones signal and converts the signal into a harmonic of the ray Leigh method of signal conversion which than introduces an analog version of the digital signal back into the original UHF carrier with the proper digital code to open the car door

Name
- Submitted On: September 29, 2006
Can bloggers grow up in their ways of communicating?

Martyn McKinney
- Submitted On: September 28, 2006
Tell us what you think - post your comments here. There is not enough information given to properly evaluate this, but my guess is that the carrier of the cellphone is being rectified in the circuit and overriding the locking mechanism.

The keyfob modulation is likely a red herring.

czar
- Submitted On: September 28, 2006
Nonsense.

From http://snopes.com/autos/techno/keyless.asp

(More than a few people have inadvertently fooled themselves into believing the cell phone method of unlocking car doors actually works because they tried it and achieved the desired results — not realizing their cars were still within range of their keyless remote devices, and the signals that unlocked the doors were transmitted the usual way [i.e., through the air], not via cellular phone connections.)

glob
- Submitted On: September 28, 2006
It could be possible if the Cell phone system could reliably trasmit interference it receives. I know my cell phone can do a good job of creating interference, but I don't know about transmitting it.

Isaiah
- Submitted On: September 27, 2006
I kid you not this really works. It actually saved my ass once! I have no idea how it works or with which cars it works on, but it sure worked on my truck! I have a Python remote start and a Sidekick 3, and it worked!

Your site sucks.
- Submitted On: September 27, 2006
This story is so full of shit. Its amazing what stupid people will believe.

Name (is not required)
- Submitted On: September 27, 2006
This is how you really use your phone to get into a locked car: 1)Call a friend that has the key. 2)Tell him you'll buy him lunch if he comes and bails you out. 3)Wait patiently for him to get there. 4)Thank him.

Chris
- Submitted On: September 27, 2006
This may we work on a few select cars that use ultrasound to send the unlock signal, but most likley it's a hoax.

name
- Submitted On: September 27, 2006
o rly

mike w
- Submitted On: September 27, 2006
fake... I'm suprised your posting this. Eat crow lately

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