A door checker drive mechanism for use in automatically opening a door may include: a door checker that limits the motion of the associated door; a power source that rotates a shaft; and, a drive train that interconnects the power source to the door. The door checker drive mechanism may be adjustable between: a first condition where the power source causes the door to open or close with respect to the body; and, a second condition where the power source cannot cause the door to open or close and the door may be manually opened or closed.