Subaru LEGACY 2003 Service Manual page 36

ENGINE MALFUNCTION INDICATOR LAMP (MIL)
ENGINE (DIAGNOSTICS)
D: CHECK ENGINE MALFUNCTION INDICATOR LAMP (MIL) DOES NOT GO
OFF.
• DIAGNOSIS:
• The CHECK ENGINE malfunction indicator lamp (MIL) circuit is shorted.
• TROUBLE SYMPTOM:
• Although MIL comes on when engine runs, trouble code is not shown on Subaru select monitor or OBD-
II general scan tool display.
• WIRING DIAGRAM:
IGNITION
RELAY
4
*
* 3
2
*
* 1
B157
3
5
COMBINATION
METER
i12
B72
1 2
3 4
1 2 3
6 7 8 9 10 11 12
B134
1 2 3 4 5 6
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
1 CHECK HARNESS BETWEEN COMBINA-
TION METER AND ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Turn ignition switch to ON.
Does the MIL come on?
B72
4
FUSE &
RELAY
BOX
B :
i5
D :
B152
i1
B36
ECM
B134
B152
1 2 3
i5
7 8 9 10 11 12 13 14
4 5
7 8
1 2
3 4 9 14 15 16
34 35
10 17
5 6
11 12 13 18
7 8
Step
EN(H4SOw/oOBD)-34
IGNITION
SWITCH
SBF-4
1
*
*
*
*
i12
4 5 6 A1 A2
B1 B2
D1 D2
E1 E2
F1
G1
H1
B157
I1
J1
K1
19 24 25 26 29 34 35 36
20 27 30 37 L1
M1 M2
21 22 23 28 31 32 33 38
O1 O2
P1 P2
Value
MIL illuminates.
No. 5
SBF-1
1 LHD : 9
RHD : 38
2 LHD : 13
RHD : 36
3 LHD : 11
RHD : 34
4 LHD : 10
RHD : 37
B36
A4 A5 A6
A3
B4 B5 B6
B3
C2 C4 C5 C6
D4 D5 D6
C3
E4 E5 E6
F6
G6
H6
I6
J6
K6
L2 L4 L5 L6
N3
M4 M5 M6
N2 N4 N5 N6
O3
O4 O5 O6
P3
P4 P5 P6
Yes
Repair short circuit
in harness
between combina-
tion meter and
ECM connector.
BATTERY
EN-01043
No
Replace ECM.
<Ref. to
FU(H4SOw/
oOBD)-42, Engine
Control Module.>