Control system for an automatic transmission in an automotive vehicle

摘要

A control system for an automatic transmission in an automotive vehicle selects an appropriate shift pattern in compliance with the temperature of hydraulic oil contained in a torque converter of the automatic transmission. The control system includes a transmission control unit having a plurality of shift patterns including a first shaft pattern favored for a cold engine and a second shift pattern favored for an engine after warm-up, an oil sensor for detecting the temperature of hydraulic oil contained in or supplied to the torque converter, a timer for counting the time period after engine starting, and a CPU for selecting either the first or second shift pattern. The first shaft pattern is selected when the temperature of hydraulic oil is less than a preset value, whereas the second shift pattern is selected when the time set by the timer is up.