Pressure Regulator Control (PRC) Solenoid
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2003 Mazda Tribute, 2003 Mazda Protege5, 2003 Mazda Protege, 2003 Mazda MX-5 Miata, and 2003 Mazda MPV. However, it is still accessible from the selected car via links, so may be relevant.
The PRC system includes a solenoid connected with a vacuum line to the fuel pressure regulator. During hot engine restarts, the PCM energizes the PRC solenoid. This prevents intake manifold vacuum from going to the fuel pressure regulator and increases fuel pressure about 8 psi (0.6 kg/cm2 ).