A microelectromechanical (MEMS) sensor, such as an accelerometer, has one more proof masses that respond to movement of the sensor, the movement of which is measured based on a distance between the one or more proof masses and on one or more sense electrodes. The accelerometer also has a plurality of auxiliary electrodes and a signal generator configured to apply an auxiliary signal having a first harmonic frequency to the plurality of auxiliary electrodes. Circuitry receives a sensed signal from the plurality of sense electrodes and identifies a portion of the sensed signal having the first harmonic frequency. Based on this identified portion of the sensed signal, the circuitry determines whether a residual voltage is present on the one or more proof masses or on the one or more sense electrodes, and the circuitry modifies the operation of the accelerometer when the residual voltage is determined to be present in order to compensate for the residual voltage.