Patent ID: 7051689
Filing Date: 2006-05-30
Classification: F01N,F02D,Y02T

Abstract:
1. A failure diagnostic system for an exhaust pressure increasing device, comprising: an intake channel and an exhaust channel in communication with a cylinder of an internal combustion engine; an exhaust pressure increasing device that increases an exhaust system pressure of said exhaust channel; an intake system pressure detecting device provided in said intake channel, for detecting an intake system pressure; an intake valve that selectively allows and prohibits communication between the intake channel and the cylinder; and an exhaust pressure increase failure diagnostic unit that determines as to whether the exhaust pressure increasing device has failed based on a maximum intake pressure generated due to a spit-back of a combustion gas in the cylinder towards the intake channel after intake valve has allowed the intake channel to communicate with the cylinder and prior to an occurrence of an exhaust pulsation or an intake pulsation, and a predetermined failure diagnosis reference range.