Patent ID: 7216697

Claim:
A method for operating a cooling and heating circuit of a motor vehicle driven by an internal combustion engine, the method comprising the steps of providing a first cooling medium path through a bypass conduit; providing a second cooling medium path through a main cooler of the internal combustion engine; providing a third cooling medium through a heating heat exchanger; providing a fourth cooling medium path through a heat accumulator; subdividing cooling medium flows through said paths by electrically operated valves; providing the cooling medium flows by at least one pump; controlling said valves by a control unit based on operational and environmental parameters as well as nominal values; arranging a third control valve which is controlled by said control unit in said fourth cooling medium path and closing the third control valve completely or partially when a reference temperature of a remaining cooling and heating circuit exceeds a nominal value provided in said control unit, and opening said third control valve when the reference temperature is below the nominal value.