Method for monitoring an electronic control unit for a motor vehicle, having the steps: - providing the electronic control unit, wherein the control unit has a control circuit, which is constructed for controlling an operating function of the motor vehicle, and a monitoring circuit, which contains at least one sensor component (S1, S2, S3), - recording a measured value (M1, M2, M3) by means of the at least one sensor component (S1, S2, S3), - determining an actual value of a characteristic value representative for the thermal, mechanical and/or chemical loading of the control unit by means of the monitoring circuit on the basis of the recorded measured value (M1, M2, M3) and comparing the actual value with a predetermined set-point value of the characteristic value, - emitting a signal by means of the monitoring circuit as a function of the result of the comparison, wherein the characteristic value is representative for the thermal, mechanical and/or chemical loading of the at least one sensor component (S1, S2, S3), characterized in that either the control circuit is different from the monitoring circuit, and the control circuit has at least one electric or electronic component, which is of the same type as the at least one sensor component (S1, S2, S3) and which is less sensitive with respect to the thermal, mechanical and/or chemical loading than the at least one sensor component (S1, S2, S3) or - the control circuit contains a plurality of similar electric or electronic components, which are part both of the control circuit and of the monitoring circuit and together contribute to controlling the operating function of the motor vehicle and are connected to one another in such a manner that the failure of an individual component of the similar components does not impair the functionality of the control circuit for controlling the operating function, and - the similar components constitute the sensor components (S1, S2, S3) and the failure of an individual or a portion of the similar components is detected for determining the actual value. - providing the electronic control unit, wherein the control unit has a control circuit, which is constructed for controlling an operating function of the motor vehicle, and a monitoring circuit, which contains at least one sensor component (S1, S2, S3), - recording a measured value (M1, M2, M3) by means of the at least one sensor component (S1, S2, S3), - determining an actual value of a characteristic value representative for the thermal, mechanical and/or chemical loading of the control unit by means of the monitoring circuit on the basis of the recorded measured value (M1, M2, M3) and comparing the actual value with a predetermined set-point value of the characteristic value, - emitting a signal by means of the monitoring circuit as a function of the result of the comparison, wherein the characteristic value is representative for the thermal, mechanical and/or chemical loading of the at least one sensor component (S1, S2, S3), characterized in that either the control circuit is different from the monitoring circuit, and the control circuit has at least one electric or electronic component, which is of the same type as the at least one sensor component (S1, S2, S3) and which is less sensitive with respect to the thermal, mechanical and/or chemical loading than the at least one sensor component (S1, S2, S3) or - the control circuit contains a plurality of similar electric or electronic components, which are part both of the control circuit and of the monitoring circuit and together contribute to controlling the operating function of the motor vehicle and are connected to one another in such a manner that the failure of an individual component of the similar components does not impair the functionality of the control circuit for controlling the operating function, and - the similar components constitute the sensor components (S1, S2, S3) and the failure of an individual or a portion of the similar components is detected for determining the actual value.