The invention relates to a motor vehicle door lock, comprising a circuit arrangement having at least one sensor (5) and a connected control unit (7), wherein the sensor (5) has at least two switching states (“open” and “closed”), which correspond to varying current intensity (I1; I2) at the output of said sensor and are detected by the control unit (7), and the two switching states (“open” and “closed”) of the sensor (5) belong to different current paths (6a; 6a, 6b) of a line network (6) and/or to different voltage states of an output line.