Unlocking your car with a cell phone?

[Jeremy airjer W]

Along with our paychecks we received a piece of literature with cell phone tips and tricks. One of them was how to use you cell phone to unlock the car. It sounded like a sham but we tried it out on a Dodge Dakota and sure enough it worked.

There are a couple of conditions for this to work. Your vehicle must have keyless entry, both people have to be on a cell phone, and the other person needs to have a spare FOB (keless entry remote). If your keys are locked in the car simple call the person's cell phone that has the spare FOB. Have them hold the FOB next to there phone and press the unlock button while you are holding your phone near the drivers window of the locked vehicle. The door should unlock.

when I read this I was thinking the same thing you are, NO WAY. Seriously, last night we unlocked and locked the Dakota several times from our business office.

Give it a try and post your results!

[irvingdog]

If that works, I'll eat my hat. Major internet hoax! Disproved on every web hoax site on the web.

Sorry Airjer. Different frequencies altogether.

[Shack]

This does in fact work on a lot of models. One of the parts guys from Holt Motors showed it to me at a party last summer.

It is pretty slick.

[Eric Wettschreck]

Do you want salt or ketchup to go with your hat?

[Shack]

Basically you are transmitting the Fob/keyless remote signal via cell towers to the phone and then the frequency emits from the receiving cell phone to body control module. Pretty much like a long distance signal. It will not work with land lines, because of the wireless emitted signal needed from a cell phone. The key benefit to that is when you lock the keys in your car/truck, the only phone most times you will have access to is a cell phone. Just make sure a significant other has a cell phone and a key fob/keyless remote on his or hers key chain. It will work on most models. I should say the model this was demonstrated to me on, was a Chrysler product. I have tried it with Fords and kind of gave up. It still might work though. Just keep trying and the receiver should move from the driver seat (if it does not work) around the front of the car to the passenger side. At some point it should work

Good thread Airjer.

[Shack]

Basically in a round about different way, it’s the same thing On-Star does for you in a Chevy.

[311Hemi]

It worked for me on my 2003 Dodge Ram. I locked my keys in my car and stood next to my car door with my phone facing the window. I then had my wife (looking at me through the window from inside the house) call my cell and then press my keyfob and the doors unlocked!!

[irvingdog]

The question is, were they still within range of the keyless remote?

Snopes, Urbandlegends and a host of others disprove this. Best answer? Try it yourself. Drive your car to Penn and West Broadway. Wave a fist full of one hundred dollar bills in the air. Then, lock your keys in your car. Call your wife in Maplewood and have her "buzz you in". Just make sure that the Originating Cell phone/RKE device is well outside it's operating range from the target vehicle. If it worked for you when you tested it the first time, it's because you were to close to the keyless remote, or your ice house isn't properly ventilating.

[LMITOUT]

It's bogus. Do a search and it's been discussed many times as a hoax.

[LovenLifeGuy]

It does not work on my 2004 silverado but I have seen it work two different times on the same dodge truck. It is not bogus and works on some vehicles.

[PierBridge]

Has anyone actually done this in a emergency situation "real world" from a distance as in miles away.

0-6 for this guy!

[Shack]

That was my first thought last summer at the party (along with others). We verified many times the fob would not unlock the van at the point we tried this at. It took a couple of times and it did end up working. Now maybe the cell phone magnified the signal of the fob, but it worked.

[Da Beak]

I'll have some of that hat too.

From the Urban Legends HSOforum...

Unlock Your Car Door with a Cell Phone

Netlore Archive: Locked out of your automobile? According to this forwarded email, you can have someone transmit a signal from your spare remote key via cell phone and unlock your car door in a pinch.

Description: Email Hoax

Circulating since: July 2004

Status: False

Analysis: See below

Email example contributed by Amanda, 19 July 2004:

Subject: Unlock your car from the outside!

This only applies to cars that can be unlocked by remote button. Should you lock your keys in the car and the spare keys are home.

If some one has access to the spare remote have them telephone you on your cell phone.

Hold your (or anyone's) cell phone about a foot from your car door and have the other person press the unlock button, hold it near the phone.

Your car will unlock. I tried it and it works. Saves someone from having to drive your keys to you. Distance is no object.

Comments: Comforting though it may be to imagine you can unlock your car door in an emergency by receiving a distant signal via your cell phone, it can't possibly work — not with the technology as it now stands, at any rate.

Here's why:

Your remote car key operates by sending a weak, encrypted radio signal to a receiver inside the automobile, which in turn activates the door locks.

Since the system works on radio waves, not sound, the only conceivable way a signal from your spare remote could be picked up by one cell phone and relayed to your car's onboard receiver by another would be if both phones were capable of sending and receiving at exactly the same frequency as the remote itself — which they can't be, given that all remote entry devices operate at frequencies between 300 and 500 MHz, while all mobile phones, by law, operate at 800 MHz and higher.

It's apples vs. oranges, in other words. Your cell phone can no more transmit the type of signal needed to unlock a car door than your remote key is capable of dialing up your Aunt Mary ... though no one can predict what miracles the future may bring.

[eyebjim]

That would be my guess. It had to amplify the signal. Otherwise you are saying that the microphone can recieve not only sound but also radio frequency. I am pretty sure that is not possible. That and then the earpiece speaker would have to be able to transmitt radio frequency. These are basically speakers. They are for sound not RF.

[Shack]

To put this into prospective, I have an older dial radio (tuned in on AM) sitting on the ledge of the window behind me in my office. It is always turned on, but the volume is turned down. I know 5-10 seconds before my cell phone rings that a call is coming in. My radio clicks and pops. It keeps clicking and popping while the phone is in use. Basically, the radio is in between (in the area) of the wireless signal coming into my office (this could be construed as the module in the car/truck) to my cell phone. I guess I should correct my self and say the signal is not going into the receiving phone and then out to the car/truck, but rather the car/truck is in the inbound lane of the incoming wireless signal. The wireless signal going into you cell phone is not just a narrow beam signal, I believe it is wide spread to make sure it finds your little cell phone. The vehicle just happens to be in the wide beam coming down or at the phone.

I feel the same is for the transmitting end phone. When the button is pressed on the fob, a wide wireless signal/frequency is blasted in every direction in a circle type patter looking for a receiver or a receiver path (in a parking lot, when you hit the panic button to find your car, you do not have to point the fob right at you car). It finds the out going signal transmitting up and away from the phone. I do not believe the remote fob signal goes into the phone and then out, but rather meets up with out going signal from phone and threw the sky and passes into a Chrysler remote module.

[doughnut03]

I work for a cell company, and it's a hoax. Sorry. It's pretty interesting reading people's "claims" that it works though!

[rowdyf]

MYTH!

[Shack]

Please explain why it would not work.

[Shack]

That's it!

I am E-mailing Myth Busters on Wed...

[311Hemi]

Mythbusters already busted it!

Episode 99: "Viewers’ Choice Special 2"

One can unlock a car door by having its remote unlocker frequency transmitted though a cell phone call.

busted

All attempts to unlock the car door via a cell phone call failed. In addition, Grant explained that car unlockers and cell phones operate on completely different frequencies.

I have the link to the video if you want to watch it!!

[eyebjim]

So you're saying it is riding the cell phone signal to the other phone. I am not sure but I think that could be possible given that the cell phone is a transmitter it could conceivably carry the FOB signal to the tower the other phone is communicating with. I would think the second cell phone has nothing to do with it if that is what is happening. It would just have to be in the area so a tower close to the car is sending the FOB signal. Boy that is a streach. I wouldn't count on it to work when you need it to.

[PierBridge]

In my opinion there is absolutely no way Airjer would tell us this worked if it didn't so either someone is playing a trick on him or this does work with certain security systems technology like, transponder, vats, passlock or passlock 2.........

0-8 now just tried an 02 Bravada.....with 2 digital cell phones.

for the nay-sayers how does On-Star do it?

[LMITOUT]

 Originally Posted By: PierBridge

for the nay-sayers how does On-Star do it?

The black helicopters that fly overhead.....

[LMITOUT]

First of all, key-less entry transmitters typically work in the 300-400MHz frequency range.

A speaker typically can reproduce a frequency of 20Hz (bass) up to 20,000 Hz (treble). Obviously better quality speakers can do better than that on both ends, but that is normal hearing range of humans, so there isn't much reason to design a speaker that exceeds those limitations. The earpiece in a cell phone is far from a high quality speaker, not to mention there is no possible way it's going to reproduce 300 MHz or even anything remotely close.

The mouthpiece is essentially the same as a speaker but works in reverse in that it picks up the sound waves from your mouth and converts it to electrical energy.

Myth: Busted.

[eurolarva]

Had a brilliant idea one day to anger some mating cats outside my house by building an oscillator that would produce a signal around 40 kilohertz (too high for humans to hear but real nasty to cats ) and blast it at 150 watts to get even with the mating cats for my loss of sleep. I built the oscillator and verified the output frequency with an oscilliscope. However when I plugged it into my stereo it would not work for the reasons mentioned above. The speakers are not rated for frequencies that high and 40 K Hz is a long way short of 300 Meg Hertz. You can not transmit radio frequencies via a telephone. If this worked you could open your garage the same way.

[DEADhead]

if you buy a ford vehicle with keypad entry, you never have to worry about locking the keys in your car. don't even need a cell phone. just the memory of your pin number.

I am of the belief that this is a busted myth. I have yet to see this work in person.