EVALUATION METHOD FOR DIAGNOSTIC FUNCTION OF VARIABLE VALVE GEAR AND DIAGNOSTIC DEVICE OF VARIABLE VALVE GEAR

摘要

PROBLEM TO BE SOLVED: To improve reliability in response delay diagnosis by evaluating whether diagnosis for response delay in a variable valve gear functions normally or not. SOLUTION: Response delay is forcedly caused by processing a target value used in feedback control of a variable valve timing device by a low-pass filter. Response diagnosis is performed in this condition to evaluate that a function of response diagnosis is abnormal when occurrence of response delay by processing the target value by the low-pass filter is not diagnosed. COPYRIGHT: (C)2006,JPO&NCIPI