METHOD OF DETERMINING ENGINE RACING AND METHOD OF PREVENTING ENGINE RACING DURING SHIFT IN VEHICULAR AUTOMATIC TRANSMISSION

摘要

Engine racing is determined during shift gear shift in an automatic transmission having clutches associated with respective gear positions, by, after a shift command is issued to effect a shift in a power-on mode, detecting the input and output rotational speed ratios of previous-gear-position and next-gear-position clutches (11c, 12c, 13c, 14c) of the transmission, and determining that engine racing has occurred if the input and output rotational speed ratio of one of the clutches which is normally greater than 1.0 during a gear shift remains below a threshold value slightly smaller than 1.0 for a predetermined period of time.