A method of monitoring a propulsion system of a vehicle includes determining a health indicator from a diagnostic signal based on electrical outputs from a resolver connected to an electric motor of the propulsion system, the diagnostic signal related to a resolver offset and/or a resolver wobble, calculating a reference value based on values of the health indicator determined during a first time period, and monitoring the health indicator over a second time period, where the monitoring includes continuously or periodically calculating a trend value of the health indicator over a plurality of cycles. The method also includes comparing each trend value to the reference value and estimating a difference between the trend value and the reference value for each cycle, predicting whether a fault will occur based on the difference, and based on the predicting indicating that a fault will occur, outputting a fault indication.