Jatco Corporation

Takamitsu Shimazu

Youji Itou

Yoshichika Hagiwara

A hydraulic switch malfunction assessment device includes a solenoid valve disposed in a hydraulic circuit of an automatic transmission and having a characteristic such that a hydraulic pressure supplied to a frictional engagement element changes due to a change in an electric current supplied to the solenoid valve, and a hydraulic switch interposed between the solenoid valve and the frictional engagement element and configured to output an ON signal when the hydraulic pressure is higher than or equal to a threshold value and output an OFF signal when the hydraulic pressure is less than the threshold value. Also provided is a controller configured to control the supplied current to a prescribed current value or less when a predetermined running condition has been met, and then assess a malfunction of the hydraulic switch, based on a state of operation of the solenoid valve and the signal from the hydraulic switch.

Hydraulic switch malfunction assessment device

When a throttle is substantially fully open and startup is not underway, a CVT control unit () controls a speed ratio in accordance with a fully open speed change line. When the throttle is substantially fully open and startup is underway, the CVT control unit () controls the speed ratio in accordance with a fully open startup speed change line. When the throttle is substantially fully open, startup is underway, and the number of times the primary pulley rotation speed exceeds a belt assurance upper limit value exceeds an assurance frequency number, the CVT control unit () controls the speed ratio in accordance with the full throttle speed change line instead of the full throttle startup speed change line, even though the throttle is substantially fully open and vehicle startup is underway.

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Isehara, Japan

Takamitsu Shimazu