Subaru 2002 IMPREZA Service Manual page 312

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
18.Diagnostic Procedure with Diagnostic Trouble Code (DTC)
A: DTC PO031
-
FRONT OXYGEN (NF) SENSOR HEATER CIRCUIT LOW IN-
PUT
-
DTC DETECTING CONDITION:
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(D0HC TURBO)-
49, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(D0HC TURBO)-46, Inspec-
tion Mode.>.
WIRING DIAGRAM:
Immediately at fault recognition
MAIN RELAY BATTERY
SBF-5
n
FRONTOXYGEN
EN1 143
EN(D0HC TURBO)-88