Brake system, vehicle and method for operating a brake system

A brake-by-wire brake system for a vehicle having at least two wheels which can be braked, comprising:

• at least two brake actuator units, each of the two brake actuator units having a brake actuator assigned to one of the wheels, which can be braked, for braking the vehicle during a driving operation,
• a driver brake actuation unit for actuation by a driver for a braking operation, the driver brake actuation unit having at least one sensor for detecting an activation of the driver brake actuation unit by the driver,
• at least one electronic control unit of the brake system which is configured, during normal operation, to activate one or more brake actuator units in order to impart a braking force to an associated wheel,
• wherein the driver brake actuation unit is coupled, for transmission of signals, to the at least one electronic control unit of the brake system, and
• wherein the driver brake actuation unit has an interface for a controller that is independent of the brake system,
• wherein the controller that is independent of the brake system is a vehicle controller that during normal operation, performs a vehicle function other than braking and is not part of the brake system, and is configured to activate the brake actuator units only in a fallback operating mode when activation of the brake actuator units by the at least one electronic control unit of the brake system is impaired.