Hydraulic system for automatic transmission for vehicle having idle-stop control

摘要

A hydraulic system for an automatic transmission for a vehicle with an engine having idle-stop control includes a bypass passage which allows communication between a first hydraulic passage downstream of a manual valve and a forward engagement element, a first switching valve arranged on the bypass passage to be switched between a communicating state and a non-communicating state, and a first switching device which switches the first switching valve between the communicating state and the non-communicating state. The first switching device switches the first switching valve to the communicating state when the hydraulic pressure is lower than a predetermined pressure.