Patent ID: 6679202
Filing Date: 2004-01-20
Classification: F01P

Abstract:
A malfunction detecting apparatus for a water temperature control valve comprising:a tube defining a radiator channel wherein the radiator channel is provided to circulate cooling water, which is flown from a water-cooled internal combustion engine cooled by a radiator and returned from said radiator to said internal combustion engine; a tube defining a bypass passage wherein the bypass channel circulates the cooling water flown out from said internal combustion engine to an outlet side of said radiator by bypassing said radiator; a water temperature control valve for adjusting a ratio of a flow rate of the cooling water passing through said radiator passage to a flow rate of the cooling water passing through said bypass passage means for detecting a temperature of said cooling water; means for setting a target temperature of the temperature of said cooling water; means for controlling said cooling water temperature by setting an opening degree of said water temperature control valve based on a target value of the temperature of said cooling water set by said target temperature setting means and a value of the temperature of said cooling water detected by said cooling water temperature detecting means and means for detecting malfunction of said water temperature control valve based on the target value of the temperature of said cooling water set by said target temperature setting means and the temperature of said cooling water detected by said cooling water temperature detecting means during controlling of said cooling water temperature control valve by said cooling water temperature control means.