Abstract: Pneumatic sensing elements are provided on the leading edges of power operated vehicle doors. If an obstruction is encountered on closing the doors, the sensing elements are compressed to cause a pressure increase which is sensed and is used to open the doors. Each time the doors are opened, operation of the system is tested by applying a gas pressure pulse to the system. The pressure pulse is gradually vented through a fixed orifice. The pressure in the system produced by the pressure pulse is sensed and is applied to a controller which compares the pressure pulse information with information for known pulses for a normally operating system and for system failures caused, for example, either by a leak or by a blockage in the system.