Subaru 2002 Impreza Service Manual page 97

EVAPORATIVE EMISSION CONTROL SYSTEM
Emission Control
(Aux.
Emission Control Devices)
7. Evaporative Emission Control System
A: GENERAL
0
The evaporative emission control system prevents fuel vapors from escaping into atmosphere.
This system includes a canister, purge control solenoid valve, fuel cut valve, and the lines connect-
ing them.
0
Fuel vapors in the fuel tank
is
introduced into the canister through the evaporation line, and are
absorbed by activated carbon in it. The fuel cut valve is also incorporated in the fuel tank line.
0
The purge control solenoid valve is controlled optimally by the ECM according to the engine
condition.
0
The pressure control solenoid valve incorporated in the fuel tank evaporation line regulates the
pressure/vacuum in the fuel tank under the control of the ECM which uses the signal from the fuel
tank pressure sensor.
NF0476
(1) Fuel gauge (7) Pressure control solenoid valve (13) Fuel tank
(2) Intake manifold (8) Drain valve
(1 4)
Fuel cut valve
(3) Throttle body (9) Drain filter (1 5) Fuel tank pressure sensor
(4)
Purge control solenoid valve (1 0) Shut-off valve (1 6) Vent valve
(5) Engine control module (ECM) (1 1 ) Fuel temperature sensor
(6) Canister
(1 2) Fuel level sensor
EC-11