Method for activating e.g. hydrodynamic retarder for heating internal combustion engine of vehicle to maintain engine operating temperature, involves activating retarder if torque is requested and temperature falls below minimum temperature

摘要

The method involves determining a current temperature of engine oil or cooling fluid of an internal combustion engine (30) by a fluid temperature sensor (45). Determination is made whether a braking torque is currently requested by a brake input unit (50) by a brake input unit-sensor (55). A retarder (20) of a vehicle (10) is automatically activated by a control unit (60) if the torque is requested and the temperature falls below a preset minimum temperature. An engine brake is activated by the control unit when an amount of the requested torque is not completely provided by the retarder. The brake input unit is an accelerator. An independent claim is also included for a device for activating a retarder of a vehicle.