A vehicle system with a vehicle control device and a vehicle device connected to the vehicle control device, wherein the vehicle device includes an antenna and a sensor detection unit configured to detect a user operation, the vehicle control device being configured to perform transmission of three kinds of drive signals for driving the antenna and reception of a detection signal output from the sensor detection unit via the same wire, wherein the drive signals are a first drive signal for transmission of a wake signal from the antenna, a second drive signal for transmission of a command signal from the antenna after reception of an affirmative response to the wake signal, and a third drive signal for transmission of a challenge signal from the antenna after reception of an affirmative response to the command signal, the vehicle control device comprising: an antenna driving unit configured to control the antenna to transmit a radio signal by transmitting the drive signal to the vehicle device; a sensor detection signal determination unit configured to perform a determination process of determining a vehicle operation corresponding to a detection signal received from the vehicle device; and a controller configured to control the antenna driving unit to transmit the drive signal, wherein the vehicle system is characterized in that the controller is configured to determine whether the timing of the transmission of the second drive signal has been reached, determine whether the determination process is being performed by the sensor detection signal determination unit at the time the timing of transmission of the second drive signal from the antenna driving unit is reached, control the antenna driving unit to transmit the second drive signal when the controller determines that the determination process is not being performed by the sensor detection signal determination unit, and control the antenna driving unit to temporarily stop the second drive signal from the antenna driving unit and to transmit the second drive signal after the sensor detection signal determination unit finishes the determination process when the controller determines that the determination process is being performed by the sensor detection signal determination unit at the timing of transmission of the second drive signal. an antenna driving unit configured to control the antenna to transmit a radio signal by transmitting the drive signal to the vehicle device; a sensor detection signal determination unit configured to perform a determination process of determining a vehicle operation corresponding to a detection signal received from the vehicle device; and a controller configured to control the antenna driving unit to transmit the drive signal, wherein the vehicle system is characterized in that the controller is configured to determine whether the timing of the transmission of the second drive signal has been reached, determine whether the determination process is being performed by the sensor detection signal determination unit at the time the timing of transmission of the second drive signal from the antenna driving unit is reached, control the antenna driving unit to transmit the second drive signal when the controller determines that the determination process is not being performed by the sensor detection signal determination unit, and control the antenna driving unit to temporarily stop the second drive signal from the antenna driving unit and to transmit the second drive signal after the sensor detection signal determination unit finishes the determination process when the controller determines that the determination process is being performed by the sensor detection signal determination unit at the timing of transmission of the second drive signal.