For monitoring a sensor using differential voltage evaluation for detecting a short circuit to ground and/or to supply voltage UB, a first resistor and a second resistor R1, R2 are assigned to the sensor, a sum voltage is determined from voltages UP, UM at terminals of the sensor, the sum voltage is compared to supply voltage UB, a ratio a of determined sum voltage to supply voltage UB is then calculated, and depending on the value for the ratio a, the occurrence of a shunt at the positive terminal and/or negative terminal of the sensor is detected.