Failure diagnostic system for atmospheric pressure detecting device

摘要

There is provided a failure diagnostic system for an atmospheric pressure detecting device, which is capable of rationally determining whether that device has failed or not and is capable of improving the diagnostic accuracy. The failure diagnostic system is comprised of an atmospheric pressure sensor for detecting an atmospheric pressure of the air taken into an engine; a condition determination section for determining that conditions required for determining that the atmospheric pressure sensor has failed are satisfied if the number of operations, in each of which the engine continuously operates for a predetermined period of time, has exceeded a predetermined number; and a failure diagnosis section for determining that the atmospheric pressure sensor has failed if a variation in the atmospheric pressure over a period of time equivalent to that predetermined number is equal to or less than a predetermined value and the required conditions have been satisfied.