A system for producing an active short circuit in an electric motor of a hybrid electric vehicle having a traction battery includes an inverter to be provided in communication with the motor and battery, and an inverter controller to generate driver signals to operate inverter switches to produce three-phase AC for the motor or to produce DC for battery charging. In response to motor speed exceeding a threshold, the controller is configured to generate driver signals to operate the inverter switches to produce an active short circuit in the motor to prevent battery overcharging. A processor and electric circuit are each configured to independently generate an active short circuit control signal operative to effectuate generation of the driver signals, the active short circuit produced based on an active short circuit control signal from the electric circuit in an absence of an active short circuit control signal from the processor.