Line Pressure Relief Valve
WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
The solenoid body assembly contains an over-pressurization relief valve that will limit the line pressure through the PCA and feedback to the pump main regulator valve. The line pressure relief valve controls line pressure spikes when cold. If this valve fails, concerns with the filter found in the solenoid body assembly may be seen.