BRAKE SYSTEM

A position detection device has at least four sensors outputting signals according to an operation amount of a brake pedal. Output signals from at least two sensors are input to a first ECU in a distinguishable manner. Output signals of at least two other sensors other than the sensor whose output signals are input to the first ECU are input to a second ECU in a distinguishable manner. A signal transmission unit transmits output signals of at least two sensors input to one of the first ECU and the second ECU to the other of the first ECU and the second ECU in a distinguishable manner. The first ECU and the second ECU identify an output signal indicating an abnormal value based on the output signals of at least four sensors, detect an operation amount of the brake pedal based on a plurality of output signals excluding an abnormal value.