| 摘要 |
PURPOSE:To realize basic running without significant inconvenience by performing speed change control according to emergency speed change control characteristic when detected signals to be input to an electronic control means to control a speed change ratio generate abnormality. CONSTITUTION:During driving a vehicle, sensor signals from an accelerator opening sensor 24 as an engine load sensor and a transmission input shaft rotation speed sensor 17 as an engine speed sensor are input to an electronic control circuit 22. If these sensor signals are normal, a speed change control signals is found in accordance with a speed change characteristic diagram with a transmission input shaft rotation speed on a vertical axis and an accelerator opening on a horizontal axis to control a speed change control valve for establishing a preset speed change ratio. On the other hand, if the signal is abnormal on the accelerator opening sensor 24 (or the rotating speed sensor 17) side, the speed change control signal is found in accordance with the speed change characteristic diagram based on only the input shaft rotation speed (or the accelerator opening) to control the speed change valve as well. |
