On-board diagnostic methods for partial filtration filters

A method of diagnosing operation of a partial filtration filter exhaust aftertreatment system, the method comprising:

• receiving an upstream exhaust temperature value corresponding to a fluid temperature downstream of a location configured to receive a diesel oxidation catalyst (DOC) component and upstream of a location configured to receive a first partial flow filter (PFF) component, the first PFF component being downstream of the location configured to receive the DOC component;
• receiving a downstream exhaust temperature value corresponding to fluid temperature downstream of a location configured to receive a second PFF component, the location configured to receive the second PFF component downstream of the location configured to receive the first PFF component;
• determining a frequency difference in a first frequency content of the upstream exhaust temperature value and a second frequency content of the downstream exhaust temperature value;
• if the frequency difference is less than a predetermined threshold, determining that the at least one of the first PFF component and the second PFF component is not present in the exhaust system;
• and
• if it is determined that at least one of the first PFF component and the second PFF component is not present in the exhaust system, indicating to a user that the at least one of the first PFF component and the second PFF component is not present in the exhaust system.

An internal combustion engine system, comprising:

• an internal combustion engine including an exhaust manifold;
• an exhaust aftertreatment system coupled to the exhaust manifold, the exhaust aftertreatment system including;
• a first location configured to receive a diesel oxidation catalyst (DOC) component, a second location configured to receive a first partial flow filter (PFF) component, the second location being downstream of the first location, and a third location configured to receive a second PFF component, the third location being downstream of the second location,
• at least one first sensor positioned downstream of the first location and upstream of the second location, the at least one first sensor configured to detect an upstream exhaust temperature value, and
• at least one second sensor positioned downstream of the third location, the at least one second sensor configured to detect a downstream exhaust temperature value;
• and
• a controller communicatively coupled to the at least one first sensor and the at least one second sensor, the controller configured to:
• determine a frequency difference in a first frequency content of the upstream exhaust temperature value and a second frequency content of the downstream exhaust temperature value;
• if the frequency difference is less than a predetermined threshold, determine that at least one of the first PFF component and the second PFF component is not present in the exhaust system;
• and
• if it is determined that at least one of the first PFF component and the second PFF component is not present in the exhaust system, indicate to a user that the at least one of the first PFF component and the second PFF component is not present in the exhaust system.