APPARATUS AND METHOD FOR DIAGNOSING BYPASS VALVE ON OIL COOLING CIRCUIT FOR VEHICLE

摘要

In the present invention, disclosed are an apparatus and a method for diagnosing a bypass valve on an oil cooling circuit for a vehicle, comprising: a measurement step measuring an oil temperature on a downstream side of a bypass valve; an estimation valve estimating an opening and closing state when the bypass valve is normally operated by comparing the oil temperature on the downstream side and a reference temperature for opening and closing the bypass valve; and a diagnosis step diagnosing failure conditions wherein the bypass valve is fixated to be opened and closed by comparing a lowest reference temperature and a highest reference temperature which are determined from an output variable wherein the oil temperature on the downstream side, a driving state, and a driving condition of a vehicle are reflected in accordance with the estimated result.