Hydraulic control system regulating method for distributing pressurized fluid to hybrid-type transmission i.e. multi-mode hybrid-type power transmission, involves modifying current auxiliary pump pressure to be equal pressure requirement

摘要

The method involves determining a current line pressure requirement of a hybrid-type transmission (12) when the engine is transitioned to an engine auto-stop mode. A start-up auxiliary pump pressure is set to be equal to minimum auxiliary pump pressure. An auxiliary pump (24) is started. A speed of the auxiliary pump is increased. Current auxiliary pump pressure is modified to be equal the current line pressure requirement by providing boost pressure to an auxiliary regulator valve. A main pump (22) is stopped. An independent claim is also included for a hydraulic control system comprising a main pump.