Abstract: A device for controlling a throttle cross-section of at least one control orifice in a bypass line extending around a throttle valve of an air intake pipe of an internal combustion engine, for regulating an idle speed of the internal combustion engine, and comprising a throttle member, a spring element for biasing the throttle member to an initial position thereof, and a positioning motor for moving the throttle member from its initial position against a bias force of the spring element, upon failure of the spring element and when the positioning motor is actuated, to establish a safety cross-section in the bypass line, a quantity of operating medium flowing through the safety cross-section being less than a quantity of operating medium flowing through a complete cross-section of the control orifice whereby idle operation of the internal combustion engine is insured.