GEAR SHIFT CONTROL METHOD AND SYSTEM FOR DUAL TYPE TRANSMISSION FOR VEHICLE

摘要

PROBLEM TO BE SOLVED: To prevent engagement to undesirable gear ratio causing transmission damages in a present running condition in a manual shift gear dual type transmission for vehicle. SOLUTION: This invention relates to control method and system to shift range 14 of a range type transmission 10 provided with a shift mechanism of (repeat H) and (double H). In a specific condition, while a target gear shift (GRT) selected by a driver is not accepted, a gear shift is achieved to an alternative gear ratio (GRALT). The alternative gear ratio (GRALT) is given as a gear ratio between position of (1/5, 2/6, 3/7, 4/8) in a main gear shift member selected by a driver, and a gear ratio in a range not selected by a driver.