| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a malfunction diagnosis device for performing malfunction diagnosis of intake air temperature sensors to determine whether the intake air temperature sensors are malfunctioned or not, while securing the determining accuracy of the malfunction diagnosis and improving the executing frequency of the malfunction diagnosis. Ž<P>SOLUTION: In an intake passage of an internal combustion engine, a supercharger is provided for supercharging intake air. In the intake passage, the upstream side intake air temperature sensor and the downstream side intake air temperature sensor are provided for detecting an intake air temperature on the upstream side beyond the supercharger and for detecting an intake air temperature on the downstream side beyond the supercharger, respectively. When such diagnosis executing conditions that supercharging pressure P of the supercharger on intake air is lower than determined supercharging pressure Pα during the operation of the engine are fulfilled, a control device calculates a deviation degree between a value THA detected by the upstream side intake air temperature sensor and a value THIA detected by the downstream side intake air temperature sensor. In accordance with the calculated deviation degree, the malfunction diagnosis of the upstream side intake air temperature sensor and the downstream side intake air temperature sensor is performed. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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