A system and method for detecting a malfunction and method for detecting a malfunction of a mechanism for a variable valve lift

摘要

A system for a vehicle includes a filtering module, an indexed average effective pressure (IMEP) determination module, and a stuck mechanism indicator module. The filtering module generates engine speeds based on positions of teeth of a gear that rotates with a crankshaft and based on a crankshaft position signal generated by a crankshaft position sensor. The IMEP determination module determines an IMEP for a combustion cycle of a cylinder of an engine based on squares of a first and a second of the engine speeds during the combustion cycle. The stuck mechanism indicator module selectively diagnoses a failure in a variable valve lift (VVL) mechanism of the cylinder based on the IMEP.