Patent ID: 6679108
Filing Date: 2004-01-20
Classification: G01M

Abstract:
A method of verifying an assumed synchronization of a crankshaft signal for a multiple cylinder four-stroke internal combustion engine based on induced misfiring a specified engine cylinder, comprising the steps of:identifying reference positions of the crankshaft signal intermediate top dead center positions of consecutively fired engine cylinders, and determining reference time intervals bounded by the identified reference positions; determining time differences between successive reference time intervals; accumulating the determined time differences in a first accumulator if the assumed synchronization is such that said consecutively fired engine cylinders include the specified cylinder, and in a second accumulator if the assumed synchronization is such that said consecutively fired engine cylinders do not include the specified cylinder; and determining whether the assumed synchronization is correct based on a detected divergence of the first and second accumulators and a direction of the detected divergence.