An automatic transmission and method including a plurality of hydraulic servos which respectively engage and disengage a plurality of frictional engagement elements, a first solenoid valve for gear shifting which is used for generating a hydraulic pressure supplied to a predetermined hydraulic servo, a second solenoid valve for lock-up which is used for generating a hydraulic pressure supplied to a fluid transmission apparatus for executing a lock-up, a hydraulic control apparatus, a first connector which connects the first solenoid valve and the hydraulic control apparatus, a second connector which connects the second solenoid valve and the hydraulic control apparatus, a failsafe mechanism which achieves a predetermined shift range in a high-speed-side when the first connector is disconnected and a gear shift processing mechanism which achieves a predetermined shift range among a plurality of shift ranges when the second connector is disconnected.