All vehicles that are equipped with power door locks have a power door lock actuator in each door. When the driver or passenger pushes the lock/unlock button, the door lock actuators lock or unlock the doors. The power door lock actuator will fail over time because of constant use. Once the door look actuator fails, the doors will not lock or unlock when the lock/unlock button is pushed. Once that happens, then a power door lock actuator replacement is needed.
When replacing the power door lock actuator, the window must be raised to the top of its range. Then the inner door trim panel is removed, the door lock linkage, if any, is disconnected from the inner door handle, and the electrical connector is disconnected from the actuator. The defective power door lock actuator is removed from the inside of the door and the new one is installed. Reconnect the electrical connector and any door lock linkage. Finally the inner door trim panel is put back into place and the new door lock actuator is tested.
Some manufacturers cover a power door lock actuator replacement under the bumper-to-bumper warranty portion of the factory warranty. There are extended auto warranties available that will cover the cost of replacing the door lock actuator. When choosing an extended warranty, be sure to look at the different levels of coverage to see which one covers the door lock actuator.