DIAGNOSIS METHOD FOR ENGINE FAILURE OF VEHICLE

摘要

A vehicle engine failure diagnosis method according to the present invention includes a first calculation step in which a control unit measures the angular acceleration of a flywheel and calculates the effective value of the measured angular acceleration when the vehicle is in an idle condition; a second calculation step in which the control unit calculates at least one of the Fast Fourier Transform (FFT) magnitude of the calculated effective value and the standard deviation of the effective value after the first calculation step; a first comparison step in which the control unit compares a preset reference value to each of one or more of the calculated Fast Fourier Transform (FFT) magnitude of the effective value and the standard deviation after the second calculation step; a failure diagnosis step in which the control unit diagnoses an abnormal combustion cylinder among multiple cylinders when at least one of the Fast Fourier Transform (FFT) magnitude and the standard deviation exceeds each cylinder reference value as a result of the first comparison step; and a failure notification step in which the control unit outputs to a display device information on the abnormal combustion cylinder after the failure diagnosis step.