SYSTEM OF ICE DIAGNOSTICS Russian patent published in 2017 - IPC F02D41/22 F02D45/00 F01N11/00 

FIELD: engines and pumps.

SUBSTANCE: is proposed comprising a catalyst (20) of exhaust gas purification, as well as a sensor (41) of the air-fuel ratio positioned on the outlet side of the exhaust gas purification catalyst reduces or stops the fuel supply by way of the fuel cutoff control and controls the air-fuel ratio of the exhaust gas, adjusting it to a rich air-fuel ratio after completing the fuel cutoff control by way of the rich restart control. The diagnostic system calculates the first change characteristic of the air-fuel ratio at the time when the output air-fuel ratio passes through the first area X of the air-fuel ratio for the first time, and the second change characteristic of the air-fuel ratio at the time when the output air-fuel ratio passes through the second area of the air-fuel ratio Y for the first time, which is different from the first area X of the air-fuel ratio. The diagnostic system concludes the following: a normal operation, an abnormal operation or need for conclusion specification, in respect of the air-fuel ratio sensor state, based on the first change characteristic of the air-fuel ratio, wherein if the conclusion about the need for conclusion specification is drawn based on the first change characteristic, the conclusion about the normal or abnormal operation of the air-fuel ratio sensor is drawn based on the second change characteristic of the air-fuel ratio.

EFFECT: elimination of the consequences of changes in the exhaust gas purification catalyst state, precise diagnostics of abnormal deterioration of the air-fuel ratio sensor reaction from the exhaust side.

17 cl, 9 dwg