FIELD: internal combustion engines.
SUBSTANCE: invention can be used in automotive internal combustion engines equipped with an exhaust gas recirculation system. Method for engine operating is that when an exhaust gas recirculation flow rate specified by a command signal is changed, the upper and lower flue gas recirculation limits are dynamically adjusted based on the exhaust gas recirculation flow rate specified by the command signal. Deterioration of the exhaust gas recirculation system based on a comparison with the threshold value of the cumulative difference between the measured exhaust gas recirculation flow and the upper exhaust gas recirculation limit or the lower exhaust gas recirculation limit to the accumulated exhaust gas recirculation command signal given is detected. Specified threshold value is based on the levels of nitrogen oxides in the exhaust gases. Exhaust gas recirculation flow is regulated based on the indication of deterioration. Car engine system is disclosed.
EFFECT: technical result is to increase the reliability and accuracy of diagnostic of the exhaust gas recirculation system.
17 cl, 8 dwg
