Gangwechsel-Steuerverfahren für automatisches Fahrzeuggetriebe

摘要

In a speed change control method for an automatic transmission for vehicles with a plurality of gearshift positions, the frictional resistance of a road surface is detected, gearshifting to at least a lowest-speed gearshift position is prohibited if the frictional resistance of the road surface is judged to be low. Preferably, gearshifting to at least the lowest-speed gearshift position is prohibited at starting the vehicle if the frictional resistance of the road surface is judged to be low. the frictional resistance of the road surface is determined to be low when the sum of detection frequency(%) of the detected frictional resistance values, each of which is a first predetermined value or less, is a second predetermined value or more.