Methods and systems are provided for monitoring an automotive electrical system including an inverter having at least one switch. First and second voltage commands corresponding to respective first and second components of a commanded voltage vector on a synchronous frame of reference coordinate system are received. A plurality of duty cycles for operating the at least one switch are calculated based on the first and second voltage commands. First and second actual voltages are calculated based on the plurality of duty cycles. The first and second actual voltages correspond to respective first and second components of an actual voltage vector on the synchronous frame of reference coordinate system. An indication of a fault is generated based on the difference between the first components of the commanded voltage vector and the actual voltage vector and the difference between the second components of the commanded voltage vector and the actual voltage vector.