Patent ID: 6789525
Filing Date: 2004-09-14
Classification: F02D,Y02T

Abstract:
A failure diagnosis apparatus for a throttle valve actuating device having actuating means for actuating a throttle valve provided in an intake system of an internal combustion engine and biasing means for biasing said throttle valve to a predetermined retention opening, said failure diagnosis apparatus comprising:first control means for performing a feedback control of said throttle valve so that an opening of said throttle valve coincides with a first predetermined opening; second control means for performing a feedback control of said throttle valve so that the opening of said throttle valve coincides with a second predetermined opening after said throttle valve is controlled to the first predetermined opening by said first control means; and determining means for determining that said throttle valve actuating device has failed when the time period during which the opening of said throttle valve remains in a predetermined determination range including the second predetermined opening, is shorter than a predetermined time period during an operation of said second control means.