key fobs

[Don Wilson]

can the automatic locks on an autombile be opened using two cell 'phones?

[ll_billym]

Well the instructions are here:

http://www.connectedinternet.co.uk/2005/11/14/ 579/

Sounds b*llocks to me but try it and let me know.

[ll_billym]

Upon further investigation, it appears the answer is no:

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

Lifted from:

http://urbanlegends.about.com/library/bl_unloc k_door.htm