Abstract: An internal combustion engine has an intake system (1) and an exhaust gas system (4). An exhaust turbocharger of the internal combustion engine has a compressor (42) arranged in the intake system (1) and a turbine (48) arranged in the exhaust gas system (4) of the internal combustion engine for driving the compressor (42). In order to diagnose the intake system (1), a charge pressure (PHS_AIC_DOWN) of the compressor (42) is determined in a predetermined operating state of the internal combustion engine. A leakage of the intake system (1) downstream of the compressor (42) is recognized if the determined charge pressure (PHS_AIC_DOWN) is lower than the predetermined base charge pressure (PUT_BAS) in the predetermined operating state.

Abstract: In a method for identifying a defective control device in an internal combustion engine, especially a control element of an intake manifold with a variable length, a swirl flap, or a tumble flap, or generally a control element in the air path of the internal combustion engine, instead of using a return message acknowledging the position of the control device, a regulating signal is detected following the successful switching of the control device, in order to use any deviations of said regulating signal above a defined threshold value to identify a defective control device.

Abstract: In an internal combustion engine, at a first operating point using no exhaust gas recirculation, a first measured value of a load variable is detected. As a function of a further operating variable, a first model value of the load variable is determined using a suction pipe model. At least one parameter of the suction pipe model is adapted such that the first model value approaches or corresponds to the first measured value. A first value of the parameter adjustment is stored. At a second operating point, using exhaust gas recirculation a second value corresponding to the first value of the parameter adjustment, is determined and stored. The first and second values of the parameter adjustment are compared and a parameter value of an exhaust gas recirculation model is adapted such that the first and the second values of the parameter adjustment approach each other or correspond to each other.

Abstract: In order to operate an internal combustion engine with a turbocharger, a boost pressure prevailing downstream of a compressor (42) of the exhaust gas turbocharger and upstream of a cylinder intake port of the internal combustion engine is regulated to a predefined desired boost pressure value (PUT_SP). An actuation signal portion (DELTA_PWM_WG) of a controller for regulating the boost pressure to a desired boost pressure value (PUT_SP) is determined. A change in the turbocharger speed (DELTA_N_TCHA) associated with the actuation signal portion (DELTA_PWM_WG) of the controller is determined in accordance with the actuation signal portion (DELTA_PWM_WG) of the controller and an operating point of the internal combustion engine. A turbocharger speed limit (N_TCHA_MAX) is determined in accordance with the determined change in the turbocharger speed (DELTA_PWM_WG).

Abstract: An internal combustion engine has an intake tract having a compressor. A verification is performed as to whether at least one predefined activation condition is met. A boost pressure (PUT) downstream of the compressor is sensed or determined. An adaptation characteristic curve or adaptation characteristic map (KF_AD) is adapted as a function of a rotational speed (N) of the internal combustion engine and the boost pressure (PUT) if the at least one actuation condition is met. A gradient is determined that is representative of a gradient of the adaptation characteristic curve or adaptation map (KF_AD). From the determined gradient, conclusions are drawn with respect to a fault in the intake tract of the internal combustion engine.

Abstract: In an internal combustion engine, at a first operating point using no exhaust gas recirculation, a first measured value of a load variable is detected. As a function of a further operating variable, a first model value of the load variable is determined using a suction pipe model. At least one parameter of the suction pipe model is adapted such that the first model value approaches or corresponds to the first measured value. A first value of the parameter adjustment is stored. At a second operating point, using exhaust gas recirculation a second value corresponding to the first value of the parameter adjustment, is determined and stored. The first and second values of the parameter adjustment are compared and a parameter value of an exhaust gas recirculation model is adapted such that the first and the second values of the parameter adjustment approach each other or correspond to each other.

Abstract: In order to operate an internal combustion engine with a turbocharger, a boost pressure prevailing downstream of a compressor (42) of the exhaust gas turbocharger and upstream of a cylinder intake port of the internal combustion engine is regulated to a predefined desired boost pressure value (PUT_SP). An actuation signal portion (DELTA_PWM_WG) of a controller for regulating the boost pressure to a desired boost pressure value (PUT_SP) is determined. A change in the turbocharger speed (DELTA_N_TCHA) associated with the actuation signal portion (DELTA_PWM_WG) of the controller is determined in accordance with the actuation signal portion (DELTA_PWM_WG) of the controller and an operating point of the internal combustion engine. A turbocharger speed limit (N_TCHA_MAX) is determined in accordance with the determined change in the turbocharger speed (DELTA_PWM_WG).

Abstract: A first camshaft misalignment value is determined from a measurement variable allocated to an engine air flow path. A second misalignment value is determined from a first operating variable outside of the air flow path. A trouble-free operation is identified when both values are smaller than a predefined first threshold. Misalignment is confirmed when one of both values is greater than the first and a difference between both values is smaller than a predefined second threshold. An air flow path fault is identified when the first value is greater and the second value is smaller than the first threshold and when the difference between both values is greater than the second threshold. A fault outside of the air flow path is identified, when the second value is greater and the first value is smaller than the first threshold and when the difference is greater than the second threshold.

Abstract: In a method for controlling an internal combustion engine comprising an intake pipe and a throttle valve that is arranged therein, the pressure in the intake pipe is regulated by modifying the opening angle of the throttle valve, and the desired pressure value is adjusted when the valve lift of the internal combustion engine changes. An apparatus for controlling an internal combustion engine has a mechanism for regulating the intake pipe pressure, the mechanism allowing the opening angle of the throttle valve to be influenced as a controlled variable. In addition, at least one device is provided for changing the valve lift of the internal combustion engine while a device is provided for adjusting the desired pressure value to the valve lift.

Abstract: Actual values of a load variable are detected by a sensor during active model trimming under different valve pressure conditions, and a model of estimated values is created. Trimming values of a model parameter are determined depending on detected and modeled values such that when the model parameter is trimmed, the modeled values approximate the detected values. A function is determined depending on the different pressure conditions and approximated to the trimming values. At different pressure conditions first lambda control values are detected. A first controller value fitted function is determined depending on the pressure conditions and approximated. When the model trimming mode is not active, second lambda control values are detected at different pressure conditions. A second controller value fitted function is determined depending on the pressure conditions and is approximated. An error of the intake system is detected depending on the fitted functions.

Abstract: An internal combustion engine has an intake system (1) and an exhaust gas system (4). An exhaust turbocharger of the internal combustion engine has a compressor (42) arranged in the intake system (1) and a turbine (48) arranged in the exhaust gas system (4) of the internal combustion engine for driving the compressor (42). In order to diagnose the intake system (1), a charge pressure (PHS_AIC_DOWN) of the compressor (42) is determined in a predetermined operating state of the internal combustion engine. A leakage of the intake system (1) downstream of the compressor (42) is recognized if the determined charge pressure (PHS_AIC_DOWN) is lower than the predetermined base charge pressure (PUT_BAS) in the predetermined operating state.

Abstract: A method for controlling an internal combustion engine with variable valve lift has the following steps: Determining the pressure in the intake manifold; predetermining the pressure in the intake manifold following a changeover of the valve lift; determining a selection criterion for a valve lift to be set; and setting that valve lift at which the higher pressure is reached in the intake manifold, unless the selection criterion requires the use of the valve lift at which the lower pressure is reached in the intake manifold.

Abstract: An internal combustion engine comprises an intake tract in which a throttle valve is disposed. The engine also comprises a camshaft which acts on gas inlet valves associated with respective cylinders. A phase-adjustment device is used to adjust a phase between the camshaft and a crankshaft. A desired air mass flow in a combustion chamber of the cylinder is determined depending on a charge requirement requested by the driver. The desired air mass flow is adjusted by varying the phase between the camshaft and the crankshaft if the desired air mass flow can be adjusted by varying the phase while substantially maintaining an actual pressure difference upstream and downstream of the throttle valve. Otherwise, the desired air mass flow is adjusted by varying the opening angle of the throttle valve.

Abstract: There is described a method for detecting the ambient pressure by a pressure sensor in the intake pipe of an internal combustion engine. A throttle flap is opened so that the pressure drop via the throttle flap can be neglected. The dethrottling of the internal combustion engine is compensated by the appropriate adjustment of the cam shaft in accordance with the operating state of the internal combustion engine, so that the measuring method is not being felt by the driver.

Abstract: The method for determining an air mass in a cylinder of an internal combustion engine with a supercharging device and with a device for variably controlling the valve overlap of the gas exchange valves is characterized by a reference characteristic curve for the air mass inside the cylinder that, according to the operating conditions, defines a linear correlation between the air mass inside the cylinder and the pressure inside the induction pipe, and when the induction pipe pressure exceeds the exhaust counter pressure, the value of the air mass from the reference characteristic curve is corrected with a value for the supercharging rate that is defined as the characteristic curve according to the operating conditions above the pressure inside the induction duct.

Abstract: The invention takes account of the residual gas exiting from the cylinder in order to reliably determine the air mass drawn in. To this end, the dependency of the air mass drawn in on the intake pressure is divided into three areas, from which the average area is modeled as a non-linear dependency of the air mass drawn in on the intake pressure.