Abstract: A pressure regulator can be used particularly in a CNG-operated motor vehicle as an electronically controlled pressure reducer for maintaining the gas pressure constant on the injection valve used for filling the respective cylinder. The pressure regulator is composed of a control unit (1), a pressure reducer (3) that is controlled by the control unit (1), and a throttle (2) which connects the gas outlets (20, 40) of the working chamber (17) of the control unit (1) and the pressure reducer (3). A piezoelectric actuator (11) which affects the valve (21, 22) of an overflow device (14) makes it possible to specifically modify the gas pressure (P2) in the working chamber (17) of the control unit (1) and simultaneously influence the position of the valve (38, 39) of the overflow device (33) of the pressure reducer (3), thus allowing the output pressure (Pout) of the pressure reducer (3) to be adjusted to a predefined desired value.

Abstract: A pressure regulator can be used particularly in a CNG-operated motor vehicle as an electronically controlled pressure reducer for maintaining the gas pressure constant on the injection valve used for filling the respective cylinder. The pressure regulator is composed of a control unit (1), a pressure reducer (3) that is controlled by the control unit (1), and a throttle (2) which connects the gas outlets (20, 40) of the working chamber (17) of the control unit (1) and the pressure reducer (3). A piezoelectric actuator (11) which affects the valve (21, 22) of an overflow device (14) makes it possible to specifically modify the gas pressure (P2) in the working chamber (17) of the control unit (1) and simultaneously influence the position of the valve (38, 39) of the overflow device (33) of the pressure reducer (3), thus allowing the output pressure (Pout) of the pressure reducer (3) to be adjusted to a predefined desired value.

Abstract: In a method for implementation of a fault diagnostic system having a number of diagnostic modules and in an in-vehicle fault diagnostic system, a second diagnostic module whose diagnostic result depends on the result of the fault diagnosis of at least one first diagnostic module begins its diagnostic cycle without waiting for the diagnostic result of the first diagnostic module. The second diagnostic module writes its diagnostic result into a secondary fault memory. When the first diagnostic module has ended its diagnostic cycle without finding a fault, the diagnostic result of the second diagnostic module is transferred from the secondary fault memory into a primary fault memory.

Abstract: A method for controlling an internal combustion engine includes the determination of a measured value of an actual torque. An estimated value of the actual torque is determined as a function of operating variables of the internal combustion engine. A correction value is calculated as a function of the estimated value and the measured value of the actual torque. A setpoint value of the torque that is to be set by the air mass flow rate is calculated as a function of a pedal position, which is determined by a pedal position sensor, and of at least one further operating variable, and correction as a function of the correction value. An actuator signal for an actuator element of the internal combustion engine is determined as a function of the corrected setpoint value of the torque.

Abstract: A method for calculating an actual fresh-air mass flowing into a cylinder with the aid of an inlet pipe flow model. The description of the flow model is based on a nonlinear differential equation. The chosen model approach contains modeling of an external exhaust-gas recycling system, variable inlet systems and systems with variable control valves. The model-assisted load detection method can be used in engine control systems based on air mass flow and on inlet pipe pressure. A correction algorithm, in the form of a model control loop allows permanent improvement of accuracy when the model parameters are inexact. That is to say model balancing is provided in steady and unsteady operational states.

Abstract: A method for determining an air mass flow into cylinders of an internal combustion engine with the aid of a model includes calculating an air mass actually flowing into a cylinder with the aid of an intake tube filling model supplying a load variable on the basis of which an injection time is determined, from input variables relating to throttle opening angle and ambient pressure and from parameters representing valve control. The load variable is used for prediction in order to estimate the load variable at an instant which is at least one sampling step later than a current calculation of the injection time.

Abstract: During lean operation of the internal combustion engine, preferably in relatively long-lasting overrunning shutoff phases, the output voltage of the sensor signal is regulated to a predetermined desired value via the heating control unit. If within the diagnosis period, fewer than a predeterminable number of monitoring results are within a tolerance range located around the desired value, then the heating circuit is classified as defective.

Abstract: A method and an engine control for suppressing vibration in the drive train of a motor vehicle include detecting a variable being dependent on a speed of an engine, deriving and evaluating a gradient from the variable, reducing a torque of the engine by varying an ignition angle if impermissible vibration is detected, and controlling the torque reduction as a function of an upper and a lower threshold value for the gradient. An ignition intervention is carried out for reducing the engine torque if the gradient is below the lower threshold. The ignition intervention is cancelled if the gradient exceeds the upper threshold value. First lower threshold values are stored in a first performance graph, and second higher threshold values are stored in a second performance graph to which a switchover is made after a first tripping of an anti-bucking function.

Abstract: In a method for checking the conversion capability of a catalytic converter, in particular a precatalytic converter associated with internal combustion engines of motor vehicles, the checking is undertaken through the use of a temperature measurement immediately downstream of the catalytic converter. Initially the temperature at the beginning and at the end of a predetermined idling phase is measured for a predetermined number of idling phases, following an overrun phase in predetermined operating states of a motor vehicle with an internal combustion engine. Then the difference of the temperature measurements for each idling phase is formed. The sum of all of the temperature differences and the sum of the duration of the idling phases are formed and subsequently a quotient of these results is formed. This quotient determines an average gradient.

Abstract: The invention relates, in particular, to the checking of the conversion of a precatalyzer associated with internal combustion engines. The checking being carried out during the overrunning of the motor vehicle given a sufficiently long idling phase. The following criteria being evaluated singly or in combination to determine if the catalyzer is operative. The first criteria checked is the difference between the temperature downstream and upstream of the catalyzer (FIG. 2). The second criteria checked is if the temperature downstream of the catalyzer is in a predetermined range (FIG. 3). The third criteria checked is if the temperature downstream and upstream of the catalyzer exhibits a minimum difference (FIG. 4). The fourth criteria checked is if the magnitude of the temperature gradient for the temperature upstream of the catalyzer is significantly greater than the magnitude of the temperature gradient of the temperature downstream from the catalyzer.

Abstract: A method for suppressing vibration in the drive train of a motor vehicle includes detecting an rpm of a vehicle engine; deriving an rpm gradient from the rpm and evaluating the rpm gradient; and reducing torque of the engine by varying an ignition angle if impermissible vibration is detected, wherein the torque reduction is controlled as a function of an upper and a lower limit value for the rpm gradient. The ignition angle is retarded if the rpm gradient drops below the lower limit value; switching back to an initial performance graph takes place if the rpm gradient exceeds the upper limit value; and the upper and the lower limit values are predetermined as a function of the engine rpm.