Terminal, vehicle control system, and vehicle control method

A vehicle control method that a terminal configured to perform communication with an in-vehicle device to control a vehicle executes, the vehicle control method comprising:

• receiving a first signal including a switching request of an operation mode of the terminal from the in-vehicle device;
• updating a predetermined value with the reception of the first signal;
• generating a second signal based on the updated predetermined value;
• transmitting the second signal to the in-vehicle device;
• receiving a third signal including a command for instructing switching of the operation mode of the terminal from the in-vehicle device;
• and
• in a case where the third signal is a response to the second signal, switching the operation mode of the terminal from a predetermined first mode to a predetermined second mode or from the predetermined second mode to the predetermined first mode.

A vehicle control system comprising:

• an in-vehicle device;
• and
• a terminal,
• wherein the in-vehicle device includes
• a first transmission unit configured to, in a case of switching an operation mode of the terminal, transmit a first signal including a switching request of the operation mode of the terminal to the terminal,
• a first reception unit configured to receive a second signal as a response to the first signal from the terminal,
• a first generation unit configured to generate a third signal including a command for instructing switching of the operation mode of the terminal based on the second signal, and
• a second transmission unit configured to transmit the third signal to the terminal, and
• wherein the terminal includes
• a second reception unit configured to receive the first signal from the in-vehicle device,
• a second generation unit configured to update a predetermined value with the reception of the first signal and generate the second signal based on the updated predetermined value,
• a third transmission unit configured to transmit the second signal to the in-vehicle device,
• a third reception unit configured to receive the third signal from the in-vehicle device, and
• a controller configured to, in a case where the third signal is a response to the second signal, switch the operation mode of the terminal from a predetermined first mode to a predetermined second mode or from the predetermined second mode to the predetermined first mode,
• and wherein the in-vehicle device and the terminal perform communication to control a vehicle.