VIDEO: Autoblog shows how to unlock your car with a cell phone
NOTE: After reading some of the excellent comments on this post, we decided to test this again from 30 miles away... and it didn't work. We're going to retest at a different location but similar distance to see what gave us the positive test. Stay tuned.
About a month ago my brother sent me an email explaining that if a friend or family member has the second key fob for your car, you can call them up on your cell phone, ask them to hold the key fob up to the phone, press the unlock button, and your car door will unlock. In theory, the sound waves from the key fob, which are unintelligible to the human ear, will be transmitted via the cell phone, and the doors will unlock. Well, we've seen enough spam emails before that were full of it, but we decided to see for ourselves if this works.
When we tested this theory, we were stunned to find out that it actually works. I was so excited that I pulled out the wife and daughter outside to shoot a quick video on the front lawn. Before getting this on camera, we tested it five times, and it worked every time but one. There was a lot of traffic during the one failed test, so our best guess is that the noise from the passing cars negated the sound from the key fob signal.
Mad props to the wife for getting eaten alive by bugs and keeping the camera still at the same time (for the most part). Hit the jump to check it out, it's pretty damn cool. Test this out with a friend or spouse, too, and let us know if it worked for you.
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Reader Comments (Page 1 of 10)
Sandeep 12:10PM (6/01/2007)
I wonder if this works with remote start (or those transmitters that let you use a push button starter if the fob is in the car).
Pretty cool nonetheless, thanks AB!
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dianazbear 1:37PM (6/06/2007)
We had to try this because my husband had the car keys and I had the fob at home. The car doors did unlock but when he used the key to start the car the alarm went off and shut the car down. And the fob over the phone would not help start the car.
K. Miller 6:19PM (6/09/2007)
I think this is BS. First like everyone below is saying, RF and audio do not mix well. Second, is there a possibility that that the cell phone signal could have boosted the signal? That is that his poor daughter and wife, who we did not see in the video, were not off to the side out of view with the second FOB. Third, I was actually dumb enough to test this with my GM car after watching this, and guess what? IT DIDNT WORK!
JP 12:21PM (6/01/2007)
I don't think so. Is this Arpril 1st or June 1st.
Most OEM systems in the US operate at 315 MHz. This would have to be a huge aftermarket POS, which yeah, runs on sound waves not unlike DTMF. Last time I checked the voice bandwidth on a phone wasn't more than 4KHz of audi.
I have a brigde for sale in the everglades, anyone interested?
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LQQKER 12:07PM (6/06/2007)
OMG how much for the bridge? And can u tell me the dimsions of the bridge and does it come with a warrenty? :P
dereck 3:19PM (6/06/2007)
how much? I like the everglades alot.
JK1 12:13PM (6/01/2007)
Hard to argue with the video but Snopes.com still says "False"...an Urban Legend...keyfobs transmit via RF signals - not "audio" tones...never tried it myself, however...
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Claude 12:20PM (6/01/2007)
Last time I checked they are both waveforms. As long as the reciever and transmiter for the phones can pick up the signal in the freq. the fob is using....
Albert Thurman 1:52PM (6/06/2007)
I've done it many times and it works. It did not work from the side of the car, but when I put the phone close to windsheild where the signal receiver is located (at the front of the dash board near the windshield wipers on the Toyota SUV), it worked fine. It will lock and unlock the doors. Other vehicles might have the signal receiver in other locations so the phone might have to be closer to where that receiver is to get the signal.
michael 11:50AM (6/07/2007)
actually i just tried it wit my 2002grand cherokee and guess what, not an urban legend its freaky it works
bill 6:50AM (6/09/2007)
I tried it with two different makes of car...a Honda, and a Saturn....NEITHER one works. Its a bunch of bull.
fusen 12:17PM (6/01/2007)
if this is true then you must be able to also record the sound with an audio recorder and then be able to leave the keyfob at home and use the playback to open the car right?
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Guenther 12:29PM (6/01/2007)
Did I miss something? Is it April 1st again instead of June 1st? I thought most systems worked on RF as well. If it IS audio based, then Yes, absolutely you could record them to your phone. I'm surprised though that in-audible tones make it past the compression of a digital phone call.
Hamud 12:18PM (6/01/2007)
HAHhaahahahahha, I never believed in that one, until now...
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Mark 12:19PM (6/01/2007)
I see that you have a Ford vehicle so this makes me want to try it with my Focus. I am a little surprised that this would work though just because it seems like sound signals wouldn't work well for a key fob. Wonder if there's another factor at play here. Maybe the cell boosts your RF frequency just like that guys head a few posts down.
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The Doctor 12:20PM (6/01/2007)
I think this has come two months late.
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Mike 12:22PM (6/01/2007)
I heard about this a couple years ago, but I heard that you had to have two bluetooth enabled cell phones in order to do it.
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polar 12:25PM (6/01/2007)
Is it April again already?!
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Steve B. 12:51PM (6/01/2007)
Sorry, don't believe you. Occams razor leads me to believe that this is simply a phony video. There are no soundwaves from the transmitter... it transmits a radio signal in the UHF band, which is picked up by the receiver. A cellular phone doesn't pick up and retransmit UHF signals... it operates in the SHF band, and digitally encodes sound waves, then digitally reconstructs them. Even if your car did use an ultrasonic transmitter, there is no way that the data would make it, due to the modulization process. Try sending a fax across a VoIP phone line.
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Ben 12:29PM (6/01/2007)
Did you ever think for a second that since you're only a block away from the car, the RF signal is reaching it?
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