A method is provided for operating a synchronous machine that can be operated in an efficient operating mode and an inefficient operating mode. In order to provide a working-point-specific torque the synchronous machine is controlled in the efficient operating mode such that a stator of the synchronous machine generates a synchronous rotary field which rotates synchronously with a rotor of the synchronous machine. In order to increase dissipated heat of the synchronous machine, which can be used to heat at least one component of the motor vehicle, the synchronous machine is transferred into the inefficient operating mode in which an asynchronous rotary field acts on the synchronous rotary field, said asynchronous rotary field superimposing dissipated heat-increasing harmonics on a fundamental wave of the synchronous rotary field while maintaining the working-point-specific torque.