Subaru Impreza 2003 Service Manual page 493

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
B: DTC P0031 — HO2S HEATER CONTROL CIRCUIT LOW (BANK 1 SENSOR 1)
—
• DTC DETECTING CONDITION:
• Immediately at fault recognition
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)-46, OP-
ERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO)-39, OPERATION, Inspec-
tion Mode.>.
• WIRING DIAGRAM:
MAIN RELAY
6
4
5
3
2
1
B47
B18
B47
1 2
2 1
3 4
4 3
5 6
Step
1 CHECK ANY OTHER DTC ON DISPLAY.
LHD
B61
FRONT OXYGEN
(A/F) SENSOR
B18
B:
B135
ECM
C:
B136
B22
E
F44 B22
1 2 3 4 1 2 3 4
5 6 7 8 5 6 7 8
9 10 11 12
13 14 15 16
Does the Subaru Select Moni-
tor or OBD-II general scan tool
display DTC P0031 and P0037
at the same time?
EN(H4SO)-81
SBF-5
2
LHD
F44
E3
B136
1 2 3 4 5 6
7 8 9 10 11 12 13 14 15 16 17
18 19 20 21 22 23 24 25 26
Check
ENGINE (DIAGNOSTICS)
BATTERY
B135
1 2 3 4 5 6 7
8 9
10 11 12 13 14 15 16 17 18 19
20 21 22 23 24 25 26 27 28
Yes
Go to step 2. Go to step 5.
E
EN-01421
No