A vehicle includes a multi-core processor having first, second, and cores and having first and second analog-to-digital converters (ADC) associated with the first and second cores, respectively. The first and second ADC are configured to convert analog phase currents to first and second digital phase current values, respectively. The multi-core processor is configured to generate first and second rotor-angle data from digital signals representing a position of the electric machine. The processor is programmed to, via the first core, estimate a first output torque of the electric machine based on the first rotor-angle data and the first digital phase current values, via the second core, estimate a second output torque based on the second rotor-angle data and the second digital phase current values, and, via the third core, command de-activation of the electric machine in response to a difference between the first and second output torques exceeding a threshold.