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: The invention proposes an engine (11) comprising a catalytic converter (12c), a first probe (120) able to deliver a first signal (Vsp) proportional to the oxygen content of an exhaust gas and installed upstream of the converter, a second oxygen probe (130) downstream of the converter and able to provide a second signal (Vsb), and means (13) for making a diagnosis regarding the operating condition of the converter, characterized in that: the second oxygen probe (130) is of the on/off type and the means (13) are designed to convert the first signal (Vsp) into a third signal (Vspb) of the on/off type and to make the diagnosis on the basis of the second and third signals (Vsb, Vspb).

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: The invention concerns a method for controlling the operating conditions of a probe (11) associated with means purifying (7) exhaust gases of an internal combustion engine (2), which consists in comparing an output signal of the probe with a reference value, and in acting on the probe (11) to decrease a difference between the output signal (S1) and the reference value.

Abstract: A method for controlling the operation conditions of a probe associated with a mechanism purifying exhaust gases of an internal combustion engine. The method compares an output signal of the probe with a reference value, and acts on the probe to decrease a difference between the output signal and the reference value.