Fuel Pressure Control Solenoid: Description and Operation

PURPOSE/OPERATION
The engine control module uses the fuel pressure control solenoid to control the vacuum to the fuel pressure control valve. This will raise the fuel pressure from approx 26 psi to approx 36 psi during hot restart conditions and the chance of fuel boiling in the fuel rail is reduced. When the ignition is turned on, the control relay applies 12 Volts to the solenoid. If during cranking if the coolant temperature sensor indicates 194°F or higher and the air temperature sensor indicates 122°F or higher, the engine control module will ground the solenoid. As a result this will bleed off the vacuum and raise the fuel pressure to 36 PSI. The engine control module will keep the solenoid grounded for 2 minutes and increase the injector pulse width to help purge any fuel vapors in the injectors.