Method for determining mass flows into the inlet manifold of an internal combustion engine

In an internal combustion engine having an intake manifold to which air is supplied and wherein an intake manifold pressure develops, a method for detecting mass flows to the intake manifold of the internal combustion engine including:

• means for controlling the air supplied to the intake manifold;
• means for detecting the intake manifold pressure;
• and, means for evaluating the intake manifold pressure;
• the method comprises the steps of:
• when the internal combustion engine is switched off, reducing the supply of air to the intake manifold in a predetermined manner whereupon the intake manifold pressure changes as function of time;
• evaluating a trace of said intake manifold pressure changes as a function of time to detect a mass flow into said intake manifold;
• and,
• wherein said internal combustion engine further includes a system supplying said intake manifold;
• and,
• when a rate of change of pressure exceeds a predetermined threshold value, drawing a conclusion as to leakage of the system.

In an internal combustion engine having an intake manifold to which air is supplied and wherein an intake manifold pressure develops, a method for detecting mass flows to the intake manifold of the internal combustion engine including:

• means for controlling the air supplied to the intake manifold;
• means for detecting the intake manifold pressure;
• and, means for evaluating the intake manifold pressure;
• the method comprising the steps of:
• when the internal combustion engine is switched off, reducing the supply of air to the intake manifold in a predetermined manner whereupon the intake manifold pressure changes as function of time;
• evaluating a trace of said intake manifold pressure changes as a function of time to detect a mass flow into said intake manifold;
• and,
• wherein a system, which supplies a mass flow to the intake manifold, is actuated in a predetermined manner and a conclusion is drawn as to the mass flow of this system from a comparison of said trace with the measured intake manifold pressure.

In an internal combustion engine having an intake manifold to which air is supplied and wherein an intake manifold pressure develops, a control unit for carrying out a method for detecting mass flows to the intake manifold of an internal combustion engine including:

• means for controlling air supplied to the intake manifold;
• means for detecting the intake manifold pressure;
• and, means for evaluating the intake manifold pressure;
• the control unit comprising means for performing the method steps of:
• when the internal combustion engine is switched off, reducing the supply of air to the intake manifold in a predetermined manner whereupon the intake manifold pressure changes as function of time;
• and,
• evaluating a trace of said intake manifold pressure changes as a function of time to detect a mass flow into said intake manifold.