Patent ID: 8812219

Claim:
A control apparatus for an internal combustion engine, the control apparatus being used in the internal combustion engine that is capable of switchably using a plurality of kinds of fuels, the control apparatus comprising: a checking portion programmed to carry out a check on the internal combustion engine over a plurality of combustion cycles; a failure diagnosing portion programmed to detect a failure, based on a result of the check carried out by the checking portion; and a fuel switch prohibiting portion programmed to control the internal combustion engine so that switching of fuels is prohibited after a start of the check; and a check result predicting portion programmed to predict whether a negative check result to be diagnosed as the failure by the failure diagnosing portion will be obtained, based on a progress status of the check, after the start of the check, wherein the fuel switch prohibiting portion controls the internal combustion engine so that the prohibition on switching of fuels is lifted when the check result predicting portion predicts that the negative check result will not be obtained after the start of the check, the checking portion is programmed to obtain a plurality of physical quantities related to failures to be checked for over the plurality of combustion cycles, and determines each of the obtained physical quantities to be a normal value or an abnormal value, the failure diagnosing portion is programmed to detect the failure when the number of the abnormal values determined by the checking portion is programmed to exceed an allowable range, and after the start of the check, the check result predicting portion is programmed to predict whether the negative check result will be obtained, based on a variation of the number of the abnormal values within the allowable range.