Line pressure variable controlling method for hydraulic system, involves calculating solenoid correction duty ratio based on clutch slip amount, modifying duty ratio with correction duty ratio and controlling solenoid valve

摘要

The method involves calculating a minimum line pressure based on an automatic transmission operating condition if current shift range is one of forward driving shift ranges. A solenoid duty ratio is calculated corresponding to the pressure. A solenoid correction duty ratio is calculated based on an amount of clutch slip if there is slip. The duty ratio is modified with correction duty ratio and a solenoid valve is controlled. An independent claim is also included for a line pressure variable control system for an automatic transmission.