FAILURE DIAGNOSING DEVICE FOR VARIABLE VALVE SYSTEM

摘要

PROBLEM TO BE SOLVED: To diagnose the failure of an operation angle sensor detecting an operation angle in a variable valve system wherein the valve lifting amount and a valve operation angle of an intake valve are continuously varied by controlling an operation angle of a control shaft so as to control the intake air amount of an engine. SOLUTION: The operation angle sensors are mounted double, and the deviation of the results of the detection by two operation angle sensors is calculated (S4). The failure of one of two operation angle sensors is determined (S7) when a condition that the deviation is more than a predetermined value (S5) is continued for longer than a predetermined time (S6), whereby the fail-safe control is performed (S8).