Subaru IMPREZA GD 2007 Series Manual page 2143

asieps_tobira_IM_US.book 76 ページ ２０１２年１月１７日 火曜日 午後３時４８分
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AH:DTC P0171 SYSTEM TOO LEAN (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect fuel system malfunction by the amount of main feedback control.
Fuel system diagnosis
(1)
(23)
(22)
(21)
(20)
(1) Purge control solenoid valve
(2) Purge solenoid valve
(3) Pressure regulator
(4) Throttle body
(5) Fuel filter
(6) Intake manifold
(7) Engine control module (ECM)
(8) Canister
(9) Pressure control solenoid valve
Diagnostic method
Fuel system is diagnosed by comparing the target air fuel ratio calculated by ECM with the actual air fuel ratio
measured by sensor.
(3)
(2)
(24)
(25)
(13)
(19)
(18) (17) (16) (15) (14)
(10) Drain valve
(11) Drain filter
(12) Shut-off valve
(13) Vent valve
(14) Fuel temperature sensor
(15) Fuel level sensor
(16) Fuel pump
(17) Jet pump
GD(STI)-76
: A
: B
(4)
(5)
(6)
(7)
(8)
(9)
(12)
(11) (10)
(18) Fuel cut valve
(19) Fuel sub level sensor
(20) Fuel tank
(21) Fuel tank pressure sensor
(22) Fuel gauge
(23) Combination meter
(24) Fuel injector
(25) Tank pressure control solenoid
EN-01770