Patent ID: 8091415

Claim:
An apparatus for detecting abnormality in an exhaust gas temperature sensor, comprising: an exhaust gas temperature sensor for detecting exhaust gas temperature of an engine; and a control unit, including a computer, adapted to execute: an exhaust gas temperature estimating process for estimating exhaust gas temperature based on engine rotation speed and engine load; a transient state determining process for determining whether or not the estimated temperature is in a transient state in which the exhaust gas temperature changes; and an abnormality determining process for determining, when the transient state determining process determines that the estimated temperature is in the transient state, whether or not abnormality occurs in the exhaust gas temperature sensor on the basis of a correlation between a change characteristic of the exhaust gas temperature estimated by the exhaust gas temperature estimating process and a change characteristic of the exhaust gas temperature detected by the exhaust gas temperature sensor, wherein the transient state determining process determines that, when the exhaust gas temperature estimated by the exhaust gas temperature estimating process changes by a predetermined temperature within a first predetermined time, the estimated temperature is in the transient state in which the exhaust gas temperature changes.