SYSTEM OF DIAGNOSTICS OF AIR-TO-FUEL SENSOR FAULT Russian patent published in 2018 - IPC F02D41/14 

FIELD: engines and pumps.

SUBSTANCE: fault diagnostics in the air-to-fuel sensor 41 includes an exhaust gas purification catalyst 20, an air-to-fuel sensor 40 disposed in the exhaust channel upstream of said exhaust gas purification catalyst along the exhaust gas flow, an air-to-fuel sensor 41, located in said exhaust channel downstream of said exhaust gas purification catalyst along the exhaust gas flow, as well as a diagnostic device that uses the output signals of said air-to-fuel sensors as a basis for the diagnostics of faults in an air-to-fuel sensor, placed downstream. The diagnostic device makes an assessment that the air-to-fuel sensor, located downstream, is fault-free when the timer-counter for counting the time during which the air-fuel ratio at the output of the said air-to-fuel sensor, located downstream, becomes a rich estimated air-fuel reference ratio that is richer than the stoichiometric air-fuel ratio, or less, sets the predetermined estimated value greater than zero.

EFFECT: accurate evaluation of the serviceability of the sensor on the discharge side, which forms the air-fuel ratio.

19 cl, 19 dwg