Abstract: A method for the diagnosis of an air supply circuit supplying air to a burner of an exhaust gas after-treatment system for an exhaust system of an internal combustion engine, wherein the air supply circuit is provided with a pumping device housed along a first duct adjusted by a shut-off valve. The method entails housing a first pressure sensor along the first duct interposed between the pumping device and the burner; housing a second pressure sensor along a second duct out of the burner; acquiring the pressure signals detected by said first and second pressure sensors; and diagnosing faults and/or malfunctions in the air supply circuit depending on the pressure signals detected by said first and second pressure sensors.

Abstract: A method for the diagnosis of an air supply circuit supplying air to a burner of an exhaust gas after-treatment system for an exhaust system of an internal combustion engine, wherein the air supply circuit is provided with a pumping device housed along a first duct adjusted by a shut-off valve. The method entails housing a first pressure sensor along the first duct interposed between the pumping device and the burner; housing a second pressure sensor along a second duct out of the burner; acquiring the pressure signals detected by said first and second pressure sensors; and diagnosing faults and/or malfunctions in the air supply circuit depending on the pressure signals detected by said first and second pressure sensors.

Abstract: An estimation method to determine the concentration of recirculated exhaust gas present in a cylinder of an internal combustion engine; the concentrations of recirculated exhaust gas in a gas mixture flowing through an intake duct are periodically stored in a buffer; a first instant is determined, in which a programming of a following combustion in the cylinder is carried out; an advance time is determined, which elapses between the first instant and a second instant in the future, in which air will be taken into the cylinder for the following combustion in the cylinder; a transport time is determined; a third instant in the past is determined by subtracting from the first instant an amount of time which is equal to the difference between the transport time and the advance time; and the concentration of recirculated exhaust gas present in the cylinder in the second instant is estimated depending on a concentration of recirculated exhaust gas contained in the buffer (30) and corresponding to the third instant.

Abstract: An estimation method to determine the concentration of recirculated exhaust gas present in a cylinder of an internal combustion engine; the concentrations of recirculated exhaust gas in a gas mixture flowing through an intake duct are periodically stored in a buffer; a first instant is determined, in which a programming of a following combustion in the cylinder is carried out; an advance time is determined, which elapses between the first instant and a second instant in the future, in which air will be taken into the cylinder for the following combustion in the cylinder; a transport time is determined; a third instant in the past is determined by subtracting from the first instant an amount of time which is equal to the difference between the transport time and the advance time; and the concentration of recirculated exhaust gas present in the cylinder in the second instant is estimated depending on a concentration of recirculated exhaust gas contained in the buffer (30) and corresponding to the third instant.