A passenger protection system for a vehicle includes a vehicle sensor control system having at least one processor and computerized memory storing vehicle control software therein, wherein the vehicle control software receives input data from a plurality of vehicle sensors. A digital control sequence is triggered in the software by a presence of at least one occupant other than a driver in the vehicle, with the digital control sequence activating and de-activating an alert system on a door of the vehicle. The alert system includes at least one of an audible alert and/or a visible alert and/or haptic alert on the door of the vehicle.