As the computer control concept develops, its application has potential answers to better fuel economy requirements in the automotive industry. Under overall programs to upgrade the total vehicle performance, Toyota has been developing automatic transmissions systematically. A new automatic transmission employing a microcomputer was introduced for better economy and driveability. The microcomputer controls shift and lock-up clutch operating schedules. The transmission ensures mechanical coupling from the low gear for high efficiency while maintaining superior shift quality with the lock-up clutch control during shift transition. It also offers shift pattern selection for various driving conditions and driver’s preference.