| 摘要 |
PROBLEM TO BE SOLVED: To provide an abnormality diagnosing device capable of correctly diagnosing abnormality over a whole detection temperature range of an exhaust temperature sensor. SOLUTION: An estimated exhaust temperature TEEST is determined based on an intake temperature TA, an exhaust flow GE, an air fuel ratio AF, an engine speed NE, and a target fuel injection quantity QCMD (S4-S6). A temperature difference DTE from a detected exhaust temperature TE (=TE-TEEST) is determined (S7). By integrating the temperature difference DTE, an integrated value IDTE is determined (S8). When the integrated value IDTE goes beyond prescribed upper and lower limits IDLH and IDLL, it is determined that the exhaust temperature sensor has a characteristic abnormality. COPYRIGHT: (C)2007,JPO&INPIT
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