An imaging system according to the present disclosure includes: an imaging device that is mounted in a vehicle, and captures and generates an image of a peripheral region of the vehicle; and a processing device that is mounted in the vehicle, and executes processing related to a function of controlling the vehicle on the basis of the image. The imaging device includes: a first control line, a first voltage generator that applies a first voltage to the first control line, a first signal line, a plurality of pixels that applies a pixel voltage to the first signal line, a first dummy pixel that applies a voltage corresponding to the first voltage of the first control line to the first signal line in a first period, a converter including a first converter that performs AD conversion on the basis of a voltage of the first signal line in the first period to generate a first digital code, and a diagnosis section that performs diagnosis processing on the basis of the first digital code. The above-described processing device restricts the function of controlling the vehicle on the basis of a result of the diagnosis processing.