Subaru 2002 IMPREZA Service Manual page 522

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
19.Diagnostic Procedure with Diagnostic Trouble Code (DTC)
A: DTC P0031 — FRONT OXYGEN (A/F) SENSOR HEATER CIRCUIT LOW IN-
PUT —
• DTC DETECTING CONDITION:
• Immediately at fault recognition
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN-49, OPERATION,
Clear Memory Mode.> and Inspection Mode <Ref. to EN-42, OPERATION, Inspection Mode.> .
• WIRING DIAGRAM:
MAIN RELAY
6
4
5
3
2
1
B47
Step
1 CHECK ANY OTHER DIAGNOSTIC TROU-
BLE CODE (DTC) ON DISPLAY.
LHD 2 LHD
F44
B61
FRONT OXYGEN
(A/F) SENSOR
B18
A: B134
ECM
C: B136
B22
E3
BATTERY
SBF-5
Check
Does the Subaru Select Moni-
tor or OBD-II general scan tool
indicate DTC P0031 and
P0037 at the same time?
EN-90
B47
1 2
3 4
5 6
B18
1 2 3
4 5 6
F44
1 2 3 4
5 6 7 8
B22
1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16
A: B134
1 2 3 4
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
24 25 26 27 28 29 30 31 32 33
C:
B136
1 2 3 4
8 9 10 11 12 13 14 15 16 17 18
21 22 23 24 25 26 27
Yes
Go to step 2. Go to step 5.
5 6 7 8
34 35
5 6 7
19 20
28 29 30
EN1400
No