Patent ID: 9109524
Filing Date: 2015-08-18
Classification: F02D,Y02T

Abstract:
1. A controller for internal combustion engine, including a rotation number detecting section to detect engine rotation number and an air-fuel ratio detecting section to detect an air-fuel ratio (A/F) of air-fuel mixture, the controller being configured to perform leaning control of the A/F, the controller further including: a rotation number difference calculating section to calculate a difference between a rotation number variation value of a worst cylinder specified as having largest rotation number variation based on the rotation number detected by the rotation number detecting section and an average value of rotation number variation values of remaining cylinders other than the worst cylinder; an estimated imbalance rate calculating section to calculate an estimated imbalance rate based on the A/F detected by the air-fuel ratio detecting section; and a lean abnormality detecting section to detect lean imbalance abnormality in a specific cylinder based on the rotation number difference calculated by the rotation number difference calculating section and the estimated imbalance rate calculated by the estimated imbalance rate calculating section.