Computer-implemented method for detecting a fault in a selective catalytic reducer assembly

A method performed by a control unit of a vehicle for detecting clogging in a selective catalytic reducer assembly of an internal combustion engine system of the vehicle, the internal combustion engine system comprises an internal combustion engine and an exhaust aftertreatment system, the exhaust aftertreatment system comprising:

• a diesel particulate filter adapted to receive exhaust gas from the internal combustion engine, and
• said selective catalytic reducer assembly positioned downstream the diesel particulate filter, as seen in an intended direction of flow from the internal combustion engine to the selective catalytic reducer assembly, the selective catalytic reducer assembly comprising a selective catalytic reducer,
• the method comprising:
• receiving, by processing circuitry of the control unit, upstream pressure information indicative of an exhaust gas pressure at a position upstream the diesel particulate filter, as seen in an intended direction of flow from the internal combustion engine to the diesel particulate filter;
• receiving, by the processing circuitry, pressure difference information indicative of a pressure difference across the diesel particulate filter,
• detecting, by the processing circuitry, based on the upstream pressure information and the pressure difference information that clogging has occurred in a portion of the exhaust selective catalytic reducer assembly due to accumulated solids in the portion, the detecting comprising:
• determining an expected pressure difference information indicative of a pressure difference across the diesel particulate filter under a condition in which the selective catalytic reducer assembly is not associated with clogging, wherein the expected pressure difference information is determined based on an expected pressure downstream said diesel particulate filter generated by a selective catalytic reducer assembly flow model of at least a portion of the selective catalytic reducer assembly,
• in response to determining that a difference between the pressure difference information and the expected pressure difference information being outside a predetermined difference range, determining that clogging has occurred in the selective catalytic reducer assembly, and
• in response to determining that clogging has occurred in the selective catalytic reducer assembly, raising a temperature of the exhaust gas to induce active regeneration of the diesel particulate filter to burn off accumulated solids inside the diesel particulate filter.