Abstract: A method is provided for monitoring of the functionality of an After Treatment Injector (ATI) for injection of a fluid in an engine exhaust gas system upstream of an exhaust gas treatment unit. The monitoring is performed by using a pressure sensor which detects the pressure of the fluid delivered to the ATI for a specific condition or injection cycle. The pressure sensor is located downstream of a flow regulator and upstream of the ATI in a conduit for supplying of a substance from a container to the ATI. An ECU is programmed to perform a predetermined sequence of opening and closing commands for the flow regulator and the ATI, furthermore perform a frequency analysis of the measured pressure value in order to monitor the functionality of the flow regulator, the ATI and the pressure sensor. The method is adapted to be used in connection with an On Board Diagnosis (OBD) system.

Abstract: A method and a system are provided for monitoring of the functionality of an After Treatment Injector (ATI) for injection of a fluid in an engine exhaust gas system upstream of an exhaust gas treatment unit. The monitoring is performed by using a pressure sensor which detects the pressure of the fluid delivered to the ATI for a specific condition or injection cycle. The pressure sensor is located downstream of a flow regulator and upstream of the ATI in a conduit for supplying of a substance from a container to the ATI. An ECU is programmed to perform a predetermined sequence of opening and closing commands for the flow regulator and the ATI, furthermore perform a frequency analysis of the measured pressure value in order to monitor the functionality of the flow regulator, the ATI and the pressure sensor. The method and system are adapted to be used in connection with an On Board Diagnosis (OBD) system.

Abstract: An internal combustion engine comprises an engine controller (ECU) governing fuel supply to the combustion engine by a fuelling map, which adapts the amount of fuel supplied to the engine responsive to engine speed, engine load and a volumetric efficiency of the engine. A variable intake system with at least one valve changes an effective tuning length of said variable intake system wherein degradation of said variable intake system can be diagnosed by comparing a calculated pressure variation of an inlet pressure of said variable intake system with a predetermined value for the pressure variation. The engine controller (ECU) adapts the fuelling map responsive to the diagnosis of degradation of the at least one valve of the variable intake system.

Abstract: An internal combustion engine comprises an engine controller (ECU) governing fuel supply to the combustion engine by a fuelling map, which adapts the amount of fuel supplied to the engine responsive to engine speed, engine load and a volumetric efficiency of the engine. A variable intake system with at least one valve changes an effective tuning length of said variable intake system wherein degradation of said variable intake system can be diagnosed by comparing a calculated pressure variation of an inlet pressure of said variable intake system with a predetermined value for the pressure variation. The engine controller (ECU) adapts the fuelling map responsive to the diagnosis of degradation of the at least one valve of the variable intake system. (FIG.

Abstract: The invention relates to a method and an arrangement for monitoring the operational status of a cyclically operated valve (5, 19), which valve is operated to allow a fluid or gaseous medium to flow from a first conduit (1, 18) to a second conduit (3, 20) due to a pressure difference between said conduits, whereby the valve (5, 19) operated using predetermined duty cycles. The method involves measuring pressure oscillations caused by the valve (5, 19) and generating an output signal, performing a frequency analysis on the signal to determine an amplitude for the signal at an oscillation frequency, comparing the amplitude of the oscillations to an expected amplitude for the oscillation frequency, and generating an error signal is if the difference between the calculated and the expected amplitudes exceeds a predetermined limit.

Abstract: The invention relates to a method and an arrangement for monitoring the operational status of a cyclically operated valve (5, 19), which valve is operated to allow a fluid or gaseous medium to flow from a first conduit (1, 18) to a second conduit (3, 20) due to a pressure difference between said conduits, whereby the valve (5, 19) operated using predetermined duty cycles. The method involves measuring pressure oscillations caused by the valve (5, 19) and generating an output signal, performing a frequency analysis on the signal to determine an amplitude for the signal at an oscillation frequency, comparing the amplitude of the oscillations to an expected amplitude for the oscillation frequency, and generating an error signal is if the difference between the calculated and the expected amplitudes exceeds a predetermined limit.