Fuel Pressure Control Solenoid: Description and Operation

Fuel Pressure Control Solenoid Circuit:

DESCRIPTION
The Fuel Pressure Control Solenoid Valve is an electromechanical, vacuum switching valve.

PURPOSE
The Engine Control Module (ECM) uses the Fuel Pressure Control Solenoid to control the vacuum to the Fuel Pressure Control Valve. This will raise the fuel pressure from approx. 34 PSI to approx. 44 PSI during hot restart conditions, thus reducing the chance of fuel boiling in the Fuel Rail.

OPERATION
When the ignition is turned "ON", the control relay applies 12 Volts to the solenoid. During cranking if the Coolant Temperature Sensor indicates 194° F or higher and the Air Temperature Sensor indicates 122° F or higher, the ECM will ground the solenoid. As a result this will bleed off the vacuum and raise the fuel pressure to 44 PSI. The ECM will keep the solenoid grounded for 2 minutes and increase the injector pulse width to help purge any fuel vapors in the injectors.