| 摘要 |
PURPOSE:To prevent the deceleration because of undue shift-down, by reliably detecting engine brake operation by a driver and effecting the shift-down operation only when the engine brake is necessary. CONSTITUTION:An engine speed is measured by a turbine rotating speed sensor 9, and a throttle opening angle is read from a throttle opening angle sensor 7. Then, a turbine rotating speed at a first speed position is obtained from a turbine rotating speed map 4a. Then, according to a difference between the engine speed and the turbine rotating speed, it is calculated whether overrun occurs or not. If the overrun occurs, a shift processing to a second speed is carried out. If the overrun does not occur, a shift processing to a first speed is carried out. Accordingly, overdrive is canceled to effect the shift-down. Thus, undue shift-down may be prevented. |
