Abstract: The invention relates to an exhaust gas treatment system comprising a catalytic particulate filter, a catalytic reduction device for the reduction of nitrogen oxides, which is mounted downstream of the catalytic particulate filter, an injection device mounted upstream of the catalytic particulate filter, a means for determining the temperature of the catalytic particulate filter and an electronic control unit able to command injection of reducing agent. The electronic control unit comprises a first control means able to command injection of the reducing agent in order to obtain a reference quantity of reducing agent stored in the filter that corresponds to a filter temperature below a threshold, and a second control means able to command the injection of reducing agent in order to obtain a reference quantity of reducing agent stored in the device that corresponds to a filter temperature higher than said threshold.

Abstract: A system and method for diagnosing selective catalytic reduction system of a motor vehicle, the system including an internal combustion engine connected by an exhaust manifold to, successively, an assembly including a nitrogen oxide catalyst and a particle filter and a selective catalytic reduction system, a mechanism draining mass of ammonia stored in the selective catalytic reduction system, a mechanism controlling draining, and a mechanism injecting urea positioned upstream of the selective catalytic reduction system, a mechanism measuring quantity of ammonia at an outlet of the selective catalytic reduction system, a system determining maximum mass of ammonia stored in the selective catalytic reduction system, and a comparison mechanism configured to transmit a fault signal based on a result of a comparison between the maximum mass of ammonia stored in the selective catalytic reduction system and a threshold.

Abstract: The invention relates to an exhaust gas treatment system comprising a catalytic particulate filter, a catalytic reduction device for the reduction of nitrogen oxides, which is mounted downstream of the catalytic particulate filter, an injection device mounted upstream of the catalytic particulate filter, a means for determining the temperature of the catalytic particulate filter and an electronic control unit able to command injection of reducing agent. The electronic control unit comprises a first control means able to command injection of the reducing agent in order to obtain a reference quantity of reducing agent stored in the filter that corresponds to a filter temperature below a threshold, and a second control means able to command the injection of reducing agent in order to obtain a reference quantity of reducing agent stored in the device that corresponds to a filter temperature higher than said threshold.