Control device of continuously variable transmission

摘要

A transmission mechanism of continuously variable transmission in a vehicle comprises a primary pulley and a secondary pulley provided with a first cylinder chamber and a second cylinder chamber, with groove widths being changed by supply of hydraulic pressure, and a belt provided between the pulleys. A hydraulic pressure to the first cylinder chamber is controlled by CVT control unit through a shift control valve according to a driving state of the vehicle, and the second cylinder chamber is continuously supplied with a line pressure. CVT control unit includes an internal memory to retain a heavy-current system fail flag according to the failure information inputted from a motor control unit. If, at start of driving, the internal memory holds failure information indicating that the electric motor driving a hydraulic pump fails in previous driving, CVT control unit outputs a shift command targeting a high range ratio for a predetermined time to thereby fill the first cylinder chamber with hydraulic pressure, and thereafter outputs a shift command targeting a normal gear ratio according to the driving state.