A sensor device includes a time determining part that determines time point information, and adds the time point information to the output supplied from a part subjected to failure diagnosis and related to generation of a failure detection signal, and to the output related to generation of a sense signal. With this structure, the failure detection signal is correlated with the sense signal by the time point information. Alternatively, the sensor device includes an output circuit that correlates the failure detection signal with the sense signal supplied at the same time point as the failure detection signal, and outputs both signals using a time division method.