Cell phones and unlocking cars

In summary, if you don't have "OnStar," you can unlock your car by calling someone on your cell phone who has the spare remote and holding the phone close to the car door.
  • #1
imabug
345
3
Has anybody heard of this myth/urban lengend? Any thoughts on how feasible it is?

This only applies to cars that can be unlocked by that remote button on your key ring. Should you lock your keys in the car and the spare keys are home, and you don't have "OnStar," here's your answer to the problem!

If someone has access to the spare remote at your home, call them on your cell phone (or borrow one from someone if the cell phone is locked in the car too!)

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

Your car will unlock. and it works. Saves someone from having to drive your keys to you. Distance is no object. You could be hundreds of miles away, and if you can reach someone who has the other "remote" for your car, you can unlock the doors (or the trunk, or have the "horn" signal go off, or whatever!)​

Everything I think I know about RF, cell phones and antennas (which admittedly isn't very much) says it shouldn't work (like the Snopes article says), but a friend of mine says she tried it with her sister who was 200 miles away and it worked.

According to the Snopes article, remote keyless entry systems operate at 300 MHz, so the only even slightly plausible explanation I could come up with was that somehow the cell phone's antenna managed to pick up a weak version of the key fob's signal and rebroadcast it through the cell network to the other side where it was received by the car.

Thoughts? I'm very skeptical about my explanation, but it's the only one I have. I would have thought that cell phones and/or cell phone networks would have filters to weed out interference like this. Maybe someone's trying to pull a fast one on me?
 
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  • #2
It isn't even conceivably possible.

- Warren
 
  • #3
chroot said:
It isn't even conceivably possible.

- Warren

Agreed. I looked this up on snopes.com a couple months ago for a similar thread here on the PF. It's a documented urban legend, which matches what EEs like chroot and I would say based on what we know about how each of those components work.

I'm too pooped to look up the link again (it's been a long weekend!), but the OP can just go to snopes.com and put in some of the key phrases from his post to get the match.
 
  • #4
Sounds to me a bit like the (more entertaining) urban legend that a parrot will mimic the same.
 

1. What is the connection between cell phones and unlocking cars?

Cell phones and unlocking cars are connected through a technology called "keyless entry", which allows a person to remotely unlock their car using a signal from their cell phone.

2. How does keyless entry work?

Keyless entry works by using a radio frequency signal to communicate between the key fob (usually attached to the cell phone) and the car's locking system. When the key fob button is pressed, it sends a signal to the car, which then unlocks the doors.

3. Can all cell phones unlock cars?

No, not all cell phones have the capability to unlock cars. The cell phone must be equipped with a keyless entry system and be synced with the car's locking system.

4. Is unlocking a car with a cell phone safe?

For the most part, unlocking a car with a cell phone is safe. However, as with any technology, there is a small risk of hackers intercepting the signal and gaining access to the car. It is important to use caution and only unlock your car with a cell phone when necessary.

5. Can cell phones also start cars?

Some cell phones have the capability to start cars as well, but this is a more advanced feature and may require additional setup and technology. It is important to check with the car manufacturer and cell phone provider for compatibility and safety precautions.

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