Patent ID: 7484367

Claim:
A defect determining device for determining a defect of a turbo charger including a boost pressure changing mechanism allowing change in boost pressure in accordance with a state of operation of an internal combustion engine, comprising: a defect determining unit determining a defect of excessive increase in exhaust gas pressure in an exhaust passage from said internal combustion engine to said turbo charger based on a degree of deviation between a target boost pressure and an actual boost pressure of said turbo charger; an engine state of operation acquirement unit sensing or calculating the state of operation of the engine; an exhaust gas pressure determining unit determining that said exhaust gas pressure is within a tolerable range of exhaust gas pressure based on an acquired state of operation of the engine; and a changing unit changing a manner of the defect determination such that the determination of defect is not readily made when the exhaust gas pressure is determined to be within said tolerable range by the exhaust gas pressure determining unit.