Disclosed are foreign object detection systems with control logic for governing use of vehicle door assemblies, and motor vehicles equipped with such FOD systems and logic. Methods are disclosed for regulating operation of a vehicle door locking mechanism. One method includes a vehicle controller determining the operating status of a control protocol that governs use of the locking mechanism. If the operating status is active, the controller receives sensor signals indicative of a location and/or velocity of an object within the sensor's supervision field. If the object is located within a protected door zone and/or the object's velocity is towards the protected zone, the controller determines whether the locking mechanism is locked or unlocked. If the locking mechanism is locked, the controller commands the locking mechanism to maintain the locked state. Conversely, if the locking mechanism is unlocked, the controller commands the locking mechanism to lock and maintain this state.