A system with a base may be mounted on a vehicle, and a carriage assembly that may be movably connected to the base and may move with respect to the base. The carriage assembly may include a motor including a motor output shaft and motor housing, and a driving mechanism may couple to a door and to the motor output shaft or the motor housing. The carriage assembly may also include a coordination bar may be coupled to the motor output shaft or the motor housing, the motor output shaft or the motor housing may rotate the coordination bar responsive to operation of the motor. At least one linkage assembly may extend or retract to move the carriage assembly to move the door between an open position and a closed position based on rotation of the coordination bar.