The present disclosure makes it possible to perform a failure diagnosis of an electric two-wheeled vehicle easily, conveniently, and immediately. The electric two-wheeled vehicle includes an electric equipment unit having an IC tag and a host unit. The host unit is capable of communicating with the IC tag, and obtains failure information of the electric equipment unit while electric power is supplied from the battery to the electric equipment unit. The information communication terminal obtains the failure information by communicating with the electric two-wheeled vehicle in a non-contact manner, and transmits the failure information to the server via the network. The server performs a failure diagnosis on the electric two-wheeled vehicle based on the failure information.