Vehicular transmission

A vehicular transmission comprising an engine, which includes a plurality of cylinders, a ratio change mechanism, which transmits a rotational driving force from said engine with a speed change, a controller, which controls operation of said ratio change mechanism, a intake pipe, through which air is supplied into said cylinders, and a throttle valve, which is used for adjusting air flow from said intake pipe to said cylinders, said engine capable of operating in a deactivated cylinder mode where at least some of said cylinders are deactivated;

• wherein:
• said ratio change mechanism includes a frictionally engaging device, which can vary a transmitted torque, and operations of said ratio change mechanism and said frictionally engaging device are controlled hydraulically;
• said controller controls the operation of said frictionally engaging device to bring said frictionally engaging device into loose engagement for a predetermined time while the cylinders that have been deactivated are being activated again in the operation of said engine;
• and
• during said predetermined time, said controller estimates a pressure inside said intake pipe from a rotational speed at an output shaft of said engine and from an opening of said throttle valve, and then estimates a driving torque generated by said engine from the rotational speed of the output shaft of said engine and the estimated pressure inside said intake pipe, and said controller, on a basis of this estimated driving torque, sets a hydraulic pressure that is applied in operational control of said ratio change mechanism.