The invention discloses a hydraulic control system based on a pulse width modulation (PWM) valve. In an embodiment, a feedback control system comprises a controller which receives a pressure intensity command signal and a pressure intensity feedback signal. The controller generates a dutyfactor control signal to control the PWM valve which provides Pc for a load, for example, an actuator in an automatic gearbox system. A pressure intensity sensor measures the Pc and provides the pressure intensity feedback signal. In another embodiment, a compensator provides compensation for linear and nonlinear effects in the pressure intensity feedback signal at least partially based on other input, such as fluid temperature. In other embodiments, a plurality of controllers are provided; based on the pressure intensity feedback signal and other input, the controller is selected by a switching logic processor or a high pass or low pass filter. The invention also discloses recalibration treatment of the Pc of the PWM valve on the response of duty factor. The recalibration method updates the treatment of a feedback control system so that the system can keep performance although abrasion, temperature and other factors gives rise to other variations.