<p>An ECU executes a program including the steps of: detecting an engine speed NE (S100); detecting a turbine speed NT (S 110); calculating a slip revolution speed N(SLP) of a torque converter as (NE-NT) (S 120); calculating a hydraulic pressure control value based on the slip revolution speed N(SLP) and a map (S130); and outputting a hydraulic pressure control signal to a linear solenoid (S 140). The map is set such that the hydraulic pressure control value is smaller as the slip revolution speed N(SLP) increases in positive values.</p>
