Patent ID: 7146267

Claim:
An engine control apparatus comprising: a crank angle detection section that detects a crank angle of a crankshaft of an engine; a cam angle detection section that detects a cam angle of a camshaft of said engine; a valve operating mechanism that drives an intake valve and an exhaust valve of said engine; and a control unit that controls said engine based on said crank angle and said cam angle; wherein said valve operating mechanism has a timing wrapping member, wrapped between said crankshaft and said camshaft, and transmits the rotation of said crankshaft to said camshaft through said timing wrapping member whereby said intake valve and said exhaust valve are driven to operate in accordance with the rotation of said camshaft; said control unit comprising: a phase detection section that detects a phase of said camshaft relative to said crankshaft based on said crank angle and said cam angle; an abnormality determination section that makes a determination, based on the phase detected by said phase detection section, as to whether said valve operating mechanism is abnormal; a threshold storage section that stores, as a lower limit threshold and an upper limit threshold, phases which become determination references of said abnormality determination section; an initial phase storage section that stores an initial phase detected by said phase detection section at the time of installation of said engine; and a phase correction section that corrects the phase detected by said phase detection section during operation of said engine with the use of said initial phase thereby to calculate a corrected phase, wherein when said corrected phase deviates from a determination reference range of from said lower limit threshold to said upper limit threshold, said abnormality determination section outputs an abnormality determination signal indicative of the generation of abnormality in said timing wrapping member.