| 摘要 |
<p>PURPOSE: To accurately sense activation of a catalyst by comparing an integration value of weight which is set based on a load in every specified cycle with a value which is set based on water temperature at the starting time, and determining catalyst activation. CONSTITUTION: A set value A serves as an activation determination reference of a catalyst based on a cooling water temperature Tw sensed by a cooling water temperature sensor 26 as an engine temperature at the starting of the engine, when an ignition switch is set ON and power is supplied to an electronic control unit 31. An intake air amount Q is read from an intake air amount sensor 27 in place of an engine load in every specified cycle. Weight K is set with reference to a table based on the intake air amount Q. A former calculated integration value B is multiplied by the weight K to obtain a new integration value B. The integration value B is compared with the set value A. When the value B exceeds the set value A, catalyst activation is determined. Air fuel ratio control is shifted to DOS control which uses outputs of an FO2 sensor 29a and an RO2 sensor 29b.</p> |
