Fuel Pressure Control Solenoid: Description and Operation

PRC Control System:

The Pressure Regulator Control Solenoid Valve, located on the fuel rail near the pressure regulator, is an ECU controlled component of the pressure regulator control (PRC) system.

The PRC system raises fuel pressure to prevent fuel percolation during hot engine restart. Under specified conditions, the ECU closes the solenoid valve to block vacuum to the fuel pressure regulator. This allows the pressure regulator to control fuel pressure without vacuum modulation. Fuel pressure is raised to slightly more than 284 kPa (41 psi).

Under the following conditions, the ECU activates the PRC system for approximately 120 seconds after starting:

1. Coolant temperature above 95°C (194°F).
2. Intake air temperature (in dynamic chamber) above 90°C (167°F).