A control system for an electric motor includes a power input calculating module configured to calculate power input to the electric motor. A power output calculating module is configured to calculate power output by the electric motor. A power loss calculating module is configured to calculate power loss in the electric motor based on the power input and the power output. A fault module is configured to compare the power loss in the electric motor to one or more predetermined power loss thresholds and to selectively alter operation of the electric motor based on the comparison.