| 摘要 |
PROBLEM TO BE SOLVED: To provide a fuel supply system diagnosis apparatus capable of performing an abnormality diagnosis on a fuel supply system with high accuracy at early timing while setting criteria in response to operation regions of an internal combustion engine.SOLUTION: A fuel supply system diagnosis apparatus comprises: a threshold table (74) in which an operation region is divided into a plurality of operation regions (R) based on the number of revolutions of an engine (n) and a throttle opening (&thetas;), and a lean threshold (S) and a rich threshold (S) of an air-fuel-ratio correction coefficient (Ka) for determining abnormality of a fuel supply system are set for each operating region (R); abnormality information acquisition means (75) determining whether the air-fuel-ratio correction coefficient (Ka) exceeds the lean threshold (S) or the rich threshold (S) extracted in response to an operating state from the threshold table (74), and acquiring abnormality information; and abnormality determination means (76) determining whether abnormality occurs to the fuel supply system, on the basis of the abnormality information acquired by the abnormality information acquisition means (75). |
