US Patent 7104907 System and method of controlling automatic transmission

In a system for controlling an automatic transmission, at the time of ultra-low temperature start with the oil temperature of −20° C. or less, control is carried out such that when the state that the actual line pressure is equal to or greater than an ultra-low set value continues for a period longer than a line-pressure low-pressure control command set time, it is determined that the line pressure is under regulation, maximizing an indicated value of the line pressure.