Subaru Legacy 2003 Service Manual page 850

ENGINE MALFUNCTION INDICATOR LAMP (MIL)
C: CHECK ENGINE MALFUNCTION INDICATOR LAMP (MIL) DOES NOT COME
ON.
• DIAGNOSIS:
• The CHECK ENGINE malfunction indicator lamp (MIL) circuit is open or shorted.
• TROUBLE SYMPTOM:
• When ignition switch is turned ON (engine OFF), MIL does not come on.
• 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 OUTPUT SIGNAL FROM ECM.
1) Turn ignition switch to ON.
2) Measure voltage between ECM connector
and chassis ground.
Connector & terminal
(B134) No. 11 (+) — Chassis ground ( − − − − ):
Is the measured value less than the speci-
fied value?
B72
4
FUSE &
RELAY
BOX
B :
i5
D : B152
i1
B36
B134 ECM
B152
i5 1 2 3
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)-31
IGNITION
SWITCH
SBF-4
1
*
*
*
*
i12
4 5 6 A1 A2
B1 B2
D1 D2
E1 E2
F1
G1
H1
B157
I1
J1
19 24 25 26 29 34 35 36 K1
L1
20 27 30 37
21 22 23 28 31 32 33 38 M1 M2
O1 O2
P1 P2
Value
1 V
ENGINE (DIAGNOSTICS)
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
Go to step 4.
BATTERY
EN-01043
No
Go to step 2.