Hydraulic pressure control apparatus for automatic transmission and control method thereof

A hydraulic pressure control apparatus for an automatic transmission having a torque converter and a powertrain, the apparatus comprising:

• an oil tank storing oil;
• a first hydraulic pump connected with the oil tank to receive oil from the oil tank, having a first motor, and adapted to generate a low pressure through an operation of the first motor;
• a second hydraulic pump fluidly connected with the first hydraulic pump to receive the low pressure, having a second motor, and adapted to generate a high pressure through an operation of the second motor;
• a first regulating valve adapted to receive the low pressure from the first hydraulic pump and to regulate a first operating pressure to supply to the torque converter;
• a second regulating valve adapted to receive the high pressure from the second hydraulic pump and to regulate a second operating pressure to supply to the powertrain;
• a control unit adapted to control operation of the first and second regulating valves;
• a first switch mounted at the first regulating valve to detect information regarding the hydraulic pressure of the first regulating valve and adapted to transmit the information to the control unit;
• and
• a second switch mounted at the second regulating valve to detect information regarding the hydraulic pressure of the second regulating valve and adapted to transmit the information to the control unit.