DETECTION FOR ABNORMALITY OF ENGINE ROTATION SENSOR AND METHOD FOR MEASURING NUMBER OF REVOLUTION OF ENGINE AT ABNORMAL TIME

摘要

PURPOSE:To measure the number of revolutions of an engine by a cylinder discriminating sensor, by judging an engine rotation sensor to be abnormal when the number of times of deviation of a calculated value from a prescribed range exceeds a prescribed value and measuring the time of intervals of cylinder discrimination signal outputted successively from the cylinder discriminating sensor when the engine rotation sensor is abnormal. CONSTITUTION:A value Me (proportional 1/Ne) corresponding to the time of intervals of a crank angle signal (TDC signal) outputted successively from the engine rotation sensor is measured; and when a ratio RMe of the current value Me indicating an engine rotation number Ne to the preceding value Me is outside a prescribed range regulated by prescribed upper limit value RMeH and lower limit value RMeL, the engine rotation sensor is judged to be abnormal. If the engine rotation sensor is judged to be abnormal, the value Me (proportional 1/Ne) corresponding to the time of intervals of the cylinder discrimination signal outputted successively from the cylinder discriminating sensor is measured, and the number of revolution of an engine Ne is measured by this value Me.