Abstract: A method and device for detecting presence of an exhaust gas treatment system in an exhaust line of an internal combustion engine. The method determines the derivative of the temperature upstream of the treatment system, determines the derivative of the temperature downstream of the treatment system, and compares the downstream temperature derivative with a threshold value for detecting absence of the treatment system using a pre-determined upstream temperature derivative level.

Abstract: A device for monitoring an operating mode of an element used for aftertreatment of exhaust gases from an internal combustion engine and to an associated method. The device includes a controller configured to receive a signal that represents a characteristic magnitude of the exhaust gases downstream of the exhaust gas aftertreatment element. In addition, the controller can receive a signal that represents engine deceleration and is configured to increment a deceleration counter with each deceleration. The controller also includes a failure counter that is incremented when a variation in the above-mentioned measured magnitude is detected during a deceleration, the controller establishing a diagnostic criterion that is a function of the two counters. The controller triggers a fault signal if the diagnostic criterion exceeds programmed limits.

Abstract: The invention concerns a method which consists in arranging a oxygen probe (21) of an exhaust pipe and observing that substantial unique increase of said representative signal towards a threshold value S1 calculated from the start of the bleeding of the nitrogen oxide trap, obtained following a variation subsequent to shift of the engine from lean mixture operating conditions to rich mixture operating conditions, being used as indicator for controlling the end of the bleeding operation. The invention is characterized in that the integration of the signal representing the time between the start of the bleeding and the end of the bleeding, then the comparison of the integration value to a threshold value S2 are used for diagnosing its ageing condition. The invention also concerns a device for implementing said method.

Abstract: A system for regenerating a catalytic particulate filter located in a diesel engine exhaust line, including an electronic control unit, a controlled fuel injector arranged upstream of the catalytic particulate filer and supplied with fuel by a controlled pump, and a sensor for measuring the fuel supply pressure of the injector. The system further detects a defect in the activating state of the pump based on the fuel supply pressure of the injector.

Abstract: A device for monitoring an operating mode of an element used for aftertreatment of exhaust gases from an internal combustion engine and to an associated method. The device includes a controller configured to receive a signal that represents a characteristic magnitude of the exhaust gases downstream of the exhaust gas aftertreatment element. In addition, the controller can receive a signal that represents engine deceleration and is configured to increment a deceleration counter with each deceleration. The controller also includes a failure counter that is incremented when a variation in the above-mentioned measured magnitude is detected during a deceleration, the controller establishing a diagnostic criterion that is a function of the two counters. The controller triggers a fault signal if the diagnostic criterion exceeds programmed limits.

Abstract: A method and device for detecting presence of an exhaust gas treatment system in an exhaust line of an internal combustion engine. The method determines the derivative of the temperature upstream of the treatment system, determines the derivative of the temperature downstream of the treatment system, and compares the downstream temperature derivative with a threshold value for detecting absence of the treatment system using a pre-determined upstream temperature derivative level.

Abstract: The invention concerns a method which consists in arranging a oxygen probe (21) of an exhaust pipe and observing that substantial unique increase of said representative signal towards a threshold value S1 calculated from the start of the bleeding of the nitrogen oxide trap, obtained following a variation subsequent to shift of the engine from lean mixture operating conditions to rich mixture operating conditions, being used as indicator for controlling the end of the bleeding operation. The invention is characterized in that the integration of the signal representing the time between the start of the bleeding and the end of the bleeding, then the comparison of the integration value to a threshold value S2 are used for diagnosing its ageing condition. The invention also concerns a device for implementing said method.

Abstract: A method for diagnosing the operating condition of an internal combustion engine exhaust gas recycling valve. The method acquires a measurement value of a reference position of the recycling valve at a predetermined time corresponding to a normally closed position of the valve, calculates the difference between the acquired reference value and a reference value acquired during a diagnostic cycle previously carried out, and compares the calculated difference with a threshold value for detecting opening of the valve.

Abstract: A method for diagnosing the operating condition of an internal combustion engine exhaust gas recycling valve. The method acquires a measurement value of a reference position of the recycling valve at a predetermined time corresponding to a normally closed position of the valve, calculates the difference between the acquired reference value and a reference value acquired during a diagnostic cycle previously carried out, and compares the calculated difference with a threshold value for detecting opening of the valve.