| 摘要 |
<p>Disclosed is a fault diagnosis apparatus which determines that an airflow meter (11) has a fault when the divergence ratio, i.e., the divergence value of the estimated intake air quantity with respect to the actual intake air quantity obtained by the airflow meter (11) is larger than the fault determination reference value determined in accordance with the rotation speed of an internal combustion engine (1). Namely, it is determined that the airflow meter (11) is normal when the divergence value of the estimated intake air quantity with respect to the actual intake air quantity is equal to or less than the fault determination reference value, and the rotation speed of the internal combustion engine (1) is equal to or larger than a predetermined engine rotation speed; and the result of the determination is maintained when the rotation speed of the internal combustion engine (1) is smaller than the predetermined engine rotation speed. Thus, whether the airflow meter is normal or the current determination result is maintained is determined in accordance with the engine rotation speed, and accordingly, the accuracy of the fault diagnosis can be improved.</p> |
