A port controller circuit implements monitoring and detection of power path short failures by regulating the control voltage to the power switches during the on-state of the power switches. A failure condition is indicated when the control voltage to a power switch is regulated to a voltage level outside of a permissible range. The port controller circuit implements real-time monitoring where a short within the power path can be detected while the power path is enabled and the fault condition can be used to disable other port controller circuits in a multi-port system. In one embodiment, a port controller circuit includes a pair of back-to-back transistors forming the power path and the real-time fault detection scheme is applied to control each transistor independently to determine if either transistor has a fault condition.