A door lock actuator is a part of a power door lock that helps the cylinder or bolt to communicate with the door's motor. The actuator tells the motor to lock or unlock the door when the correct key is used, such as the combination on a keypad or the button on a key fob.
Power door locks require electronic input to operate. The input can be given by a physical key, a key card or some other method. When the correct input is given, the actuator activates the motor, which locks or unlocks the door. In addition to cars, actuators are used on homes and other products secured by electronic locks.