Diagnostic procedure of an oxidation catalyst by measuring the rate of nitrogen oxides downstream of a selective catalytic reduction system

摘要

A diagnostic procedure of an oxidation catalyst (40) in an exhaust line (20) of gases (90) from an internal combustion engine (80), the exhaust line (20) comprising a selective catalytic reduction system (60) downstream of the oxidation catalyst (40) according to the direction of escape of the gases, the process being characterized in that it comprises: - the measurement of the rate of nitrogen oxides downstream of the selective catalytic reduction organ (60 ) according to the direction of escape of the gases (90) by means of a single NOx sensor (64) disposed downstream of the selective catalytic reduction system; - the determination of a failure of the oxidation catalyst (40) as a function of the rate of nitrogen oxides measured, the failure of the oxidation catalyst (40) being determined when the rate of nitrogen oxides measured exceeds a predetermined threshold of nitrogen oxides of oxidation catalyst failure (40); - signaling the failure of the oxidation catalyst (40).