If that connector had been connected to something recently I would not expect that undisturbed layer of dirt inside the shell. Also, the terminals don't appear to have score marks from a mating connection, although the angle of the photo is not ideal for seeing the flats of the terminals.

The OBD-II should be active with the key in the Run position. Often if you have the vehicle running you'll be instructed to shut the engine off. But you typically do need to be able to at least select Run.

-Rod