Subaru 2009 IMPREZA Service Manual page 826

Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
2. COMPONENT DESCRIPTION
Pressure control solenoid valve
PCV controls the fuel tank pressure to be equal to the atmospheric air pressure. Normally, the solenoid is set
to OFF. The valve opens and closes mechanically in accordance with the pressure difference between tank
and atmospheric air, or tank and canister.
The valve is forcibly opened by setting the solenoid to ON at the time of diagnosis.
(b)
(a) Barometric pressure
(1) Solenoid
(2) Diaphragm
(1)
(3)
(2)
(b) Fuel tank
(3) Valve
GD(H4SO)-102
(a)
(4)
(c)
(c) Canister
(4) Spring
EN-01715