An electronic shift control device for an automatic power transmission causing the level of vehicle speed at which shifting takes place to change in dependence on driving conditions to prevent the engine from over speeding or to increase the engine output torque for quick acceleration.
Sensor sensing vehicle speed throttle valve position, position of a manual selector lever and a kick-down position of an accelerator pedal generate voltages which are fed into a gear shift control circuit which computes an appropriate gear reduction ratio at all times and generates a corresponding command signal for changing the reduction ratio or shifting over a wide vehicle speed range, whenever necessary.
