ON-BOARD DIAGNOSTIC METHOD AND SYSTEM FOR DETECTING MALFUNCTION CONDITIONS IN MULTIAIR TM ENGINE HYDRAULIC VALVE TRAIN

摘要

An on-board diagnostic system for detecting malfunction conditions in a hydraulic valve train of a MultiAir(TM) engine. The system comprises a plurality of pressure sensors (12a-n) for generating pressure signals located in a hydraulic circuit of the hydraulic valve train; and an engine control module (16) for performing a waveform analysis of the pressure signals to detect malfunction conditions in the hydraulic valve train. The engine control module (16) performs a frequency and/ or time delay waveform analysis.