Abstract: In the apparatus for controlling a coasting air recirculation valve of the turbocharger of an internal combustion engine, the coasting air recirculation valve is arranged in the coasting air recirculation line bypassing a compressor in the intake duct, and the coasting air recirculation valve is controllable by way of the intake duct pressure on the downstream side of the throttle valve. In order to ensure defined opening and closing of the coasting air recirculation valve, an additional control pressure, with which the coasting air recirculation valve can be opened independently of the intake duct pressure, can be delivered to the coasting air recirculation valve.

Abstract: To achieve a very sturdy automatic control of the boost pressure, the integration of system deviation of the boost pressure, which is carried out by an integrator, is limited to a predefinable limiting value. Limiting value is composed of a basic value and a correction value superimposed upon it. Correction value is determined adaptively as a function of speed, a plurality of speed ranges being predefined. Adapted correction value can be increased or reduced stepwise, which mainly depends on whether the integral-action component of the manipulated variable for the boost pressure is smaller or greater than the current limiting value.

Abstract: An arrangement enabling a reliable detection of speed-of-rotation deviations between two exhaust-gas turbochargers of an internal combustion having separate cylinder banks included a device, which determines the difference between the pressures prevailing in the two exhaust trains of the two cylinder banks upstream from the exhaust turbines and signals a relevant speed deviation when the pressure difference determined exceeds a specifiable threshold.