Method and device for operating a power steering system

A device in a power steering system of a motor vehicle, the device configured to:

• actuate an electric motor configured to produce a motor torque to superimpose the motor torque on a specified manual torque using a superposition unit,
• detect incipient freezing of the power steering system;
• prevent freezing of the power steering system by actuating the electric motor with an oscillating control signal to apply a shaking torque having a maximum torque;
• and
• produce the oscillating control signal with first periods having a first amplitude and second periods having one of a zero amplitude and a second amplitude, whereby in the first periods the shaking torque is applied with an increased maximum torque without thermal overloading of components of the electric motor and a controller thereof.

A power steering system for a motor vehicle, the power steering system comprising:

• a steering control;
• an electric motor;
• a superposition unit configured to superimpose a motor torque applied by the electric motor onto a specified manual torque;
• and
• a device configured to:
• detect incipient freezing of the power steering system;
• prevent the freezing of the power steering system by actuating the electric motor with an oscillating control signal to apply a shaking torque having a maximum torque;
• and
• produce the oscillating control signal with first periods having a first amplitude and second periods having one of a zero amplitude and a second amplitude, whereby in the first periods the shaking torque is applied with an increased maximum torque without thermal overloading of components of the electric motor and a controller thereof.