<P> Keyless remotes contain a short - range radio transmitter , and must be within a certain range , usually 5 -- 20 meters , of the car to work . When a button is pushed , it sends a coded signal by radio waves to a receiver unit in the car , which locks or unlocks the door . Most RKEs operate at a frequency of 315 MHz for North America - made cars and at 433.92 MHz for European , Japanese and Asian cars . Modern systems since the mid-1990s implement encryption as well as rotating entry codes to prevent car thieves from intercepting and spoofing the signal . Earlier systems used infrared instead of radio signals to unlock the vehicle , such as systems found on Mercedes - Benz , BMW and other manufacturers . </P>
<P> Keyless remotes contain a short - range radio transmitter , and must be within a certain range , usually 5 -- 20 meters , of the car to work . When a button is pushed , it sends a coded signal by radio waves to a receiver unit in the car , which locks or unlocks the door . Most RKEs operate at a frequency of 315 MHz for North America - made cars and at 433.92 MHz for European , Japanese and Asian cars . Modern systems since the mid-1990s implement encryption as well as rotating entry codes to prevent car thieves from intercepting and spoofing the signal . Earlier systems used infrared instead of radio signals to unlock the vehicle , such as systems found on Mercedes - Benz , BMW and other manufacturers . </P>
what is the range of a key fob
what is the range of a key fob
usually 5 -- 20 meters
usually 5 -- 20 meters