A card interface direction detection system includes a card. A power pin is mounted to the card and connected to a power source. A ground pin is mounted to the card and connected to a ground. A direction pin is mounted to the card. A controller is coupled to an information handling system (IHS) and that includes an in node and an out node that are each connected to the direction pin. The in node is directly connected to the direction pin and a resistor is located between the out node and the direction pin such that a signal sent through out node results in a signal received through the in node that allows the controller to detect whether the mode of operation of the card is supported by the IHS.