| 摘要 |
<P>PROBLEM TO BE SOLVED: To exactly determine an abnormality of a water temperature sensor without an erroneous determination in a cooling system for stopping circulation of cooling water in an engine. <P>SOLUTION: When a temperature difference between an intake air temperature tha detected by an intake air temperature sensor 23 and an engine water temperature thw1 detected by an engine water temperature sensor 21 is greater than a prescribed value, a changeover valve 10 is opened to cause cooling water to flow into an engine cooling water passage 201, thereby mixing cooling water in the engine 1 and cooling water in a heater passage (bypass passage) 202. If a temperature difference [thw1-thw2] between the engine water temperature thw1 and a heater inlet water temperature (bypass water temperature) thw2 after the changeover valve 10 is opened is a prescribed value or less, the engine water temperature sensor 21 is determined to be normal. If the temperature difference [thw1-thw2] is greater than the prescribed value, the engine water temperature sensor 21 is determined to be abnormal. <P>COPYRIGHT: (C)2012,JPO&INPIT |
