DIAGNOSIS APPARATUS FOR INTERNAL COMBUSTION ENGINE

摘要

<P>PROBLEM TO BE SOLVED: To surely detect degradation of emission caused by reduction of afterburning quantity due to secular change and the like at low cost by comparing a value of actual water temperature sensor with water temperature estimated from a running state of an internal combustion engine. Ž<P>SOLUTION: A diagnosis apparatus for the internal combustion engine equipped with a cold engine strategy means, includes: a water temperature measuring means for detecting temperature of coolant of the internal combustion engine; a water temperature estimating means for calculating estimated water temperature of the coolant in accordance with the running state of the internal combustion engine; and a cold engine strategy abnormality determining means for determining abnormality of the cold engine strategy means in accordance with the measured water temperature and the estimated water temperature. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž