INTERNAL COMBUSTION ENGINE EXHAUST EMISSION CONTROL SYSTEM AND FILTER FAILURE DETERMINATION METHOD OF INTERNAL COMBUSTION ENGINE EXHAUST EMISSION CONTROL SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a technique capable of executing a filter failure diagnosis with high accuracy.SOLUTION: An exhaust emission control system including PM detection means provided downstream of a filter provided in an exhaust passage of an internal combustion engine, and collecting particulate matters contained in exhaust gas and detecting an amount of the particulate matters by applying a voltage between electrodes, and determining whether a failure occurs to the filter (S113 to S115) on the basis of an output signal from the PM detection means at predetermined time (S112), changes the voltage applied between the electrodes in response to at least one of a concentration of the particulate matters in the exhaust gas near the PM detection means, a flow velocity of the exhaust gas, and a temperature difference between a temperature of the exhaust gas and a temperature of the PM detection means (S106 to S111).