Hydraulic pressure control apparatus for automatic transmission

A hydraulic pressure control apparatus for an automatic transmission, comprising:

• a range selector valve outputting predetermined level of pressures for selecting one of a park position, a reverse drive range, a neutral range, and a forward drive range in accordance with the level of the outputted pressure;
• a plurality of frictional engagement elements for establishing a plurality of gear shift stages, the frictional engagement elements being controlled to engage or disengage by a hydraulic pressure and including a multiple use frictional engagement element applied in common when a first speed stage of the forward drive range, the reverse drive range, the park position, and the neutral range are selected;
• a first hydraulic pressure supply source supplying an engaging hydraulic pressure for engaging the multiple use frictional engagement element;
• a second hydraulic pressure supply source supplying an engaging hydraulic pressure for engaging the multiple use frictional engagement element;
• and
• a switching mechanism switching a first state where the engaging hydraulic pressure is supplied from the first hydraulic pressure supply source to the multiple use frictional engagement element when the park position or the neutral range is selected and a second state where the engaging hydraulic pressure is supplied from the second hydraulic pressure supply source to the multiple use frictional engagement element when the forward drive range or the reverse drive range is selected, the switching mechanism switching the first state and the second state in accordance with the level of pressures outputted from the range selector valve.