Power door locks

Many cars today also feature systems which can unlock such things as the luggage compartment or fuel filler cap door.

In 1980, Ford Motor Company introduced an external keypad-type keyless entry system, wherein the driver entered a numeric combination —either pre-programmed at the factory or one programmed by the owner— to unlock the car without the key.

During the 1990s the Subaru Legacy could also be opened by pulling the drivers external door handle a specific number of times to enter a passcode number that would unlock the driver's door only.

Today, many cars with power door locks also have a radio frequency remote keyless system, which allows a person to press a button on a remote control key fob, the first being available on the French made Renault Fuego in 1982.

[1] Currently, many luxury makers also allow the windows to be opened or closed by pressing and holding a button on the remote control key fob, or by inserting the ignition key and holding it in the lock or unlock position in the external driver's door lock.

Animation of how a power lock system works (simple relay operation)
Pressing a button on the key unlocks all of the car doors. Another button locks the car.