Subaru 2009 IMPREZA Service Manual page 823

Diagnostic Trouble Code (DTC) Detecting Criteria
BF:DTC P0442 EVAPORATIVE EMISSION CONTROL SYSTEM LEAK DETECTED
(SMALL LEAK)
1. OUTLINE OF DIAGNOSIS
Check if there is a leakage in fuel system or not, and perform the function diagnosis of valve.
(1)
(13)
(1) Fuel gauge
(2) Intake manifold
(3) Throttle body
(4) Purge control solenoid valve
(5) Engine control module (ECM)
(6) Canister
In this system diagnosis, check for leakage and valve function is conducted by changing the fuel tank pres-
sure and monitoring the pressure change using the fuel tank pressure sensor. When in 0.04 inch diagnosis,
perform in the order of mode Z
perform in the order of mode A
(3)
(2)
(15)
(14)
(16)
(12)
(11)
(7) Pressure control valve
(8) Drain valve
(9) Drain filter
(10) Shut-off valve
(11) Fuel temperature sensor
mode A mode B
mode B mode C
GD(H4SO)-99
(4)
(5)
(7)
(10)
mode C and mode D; When in 0.02 inch diagnosis,
mode D and mode E.
GENERAL DESCRIPTION
(9)
(8)
(6)
(12) Fuel level sensor
(13) Fuel tank
(14) Fuel cut valve
(15) Fuel tank pressure sensor
(16) Vent valve
EN-04151