| 摘要 |
PURPOSE:To shift a transmission automatically and appropriately in an automatic transmission gear for a vehicle even in the case of abnormality being generated to a vehicle speed sensor. CONSTITUTION:An engine 1 is connected to a transmission 3 through a torque converter 2, and the transmission 3 is connected to a driving axle through a final gear 4. In a control device 14, a first gear ratio determined on the basis of the vehicle speed signal of a vehicle speed sensor 11 and the throttle opening signal of a throttle sensor 13 is compared with a second gear ratio determined on the basis of the engine speed signal of an engine speed sensor 12 and the throttle opening signal, and the higher gear ratio is selected to shift the transmission 3. Even in the case of either one of the first and second gear ratios demanding a shift to an abnormally low gear ratio due to the abnormality of the vehicle speed sensor 11 or engine speed sensor 12, sudden down-shift is prevented because of selecting the higher gear ratio between the first and second gear ratios, and automatic shift can be performed appropriately on the basis of the normal vehicle speed or engine speed. |
