Patent ID: 6473687
Filing Date: 2002-10-29
Classification: F02D,F02P

Abstract:
An engine control unit comprising:pulse interval measuring means for receiving a crank signal of a pulse train of a predetermined angle interval corresponding to rotation of a crankshaft of an engine and measuring a pulse interval; frequency multiplication signal generating means for generating frequency multiplication signals of an integer times a next pulse in accordance with the pulse interval measured by the pulse interval measuring means; a counter which operates in accordance with the frequency multiplication signals; failure detecting means for detecting a failure in a crank signal system which supplies the crank signal; switching means for switching the counter so as to be used as a free-run counter which operates in accordance with time clocks when the failure in the crank signal system is detected by the failure detecting means; and means for generating a control signal for controlling the engine in accordance with a value of the counter.