Subaru Legacy 2003 Service Manual page 1883

ENGINE MALFUNCTION INDICATOR LAMP (MI)
ENGINE (DIAGNOSTICS)
D: CHECK ENGINE MALFUNCTION INDICATOR LAMP (MI) DOES NOT GO
OFF.
• DIAGNOSIS:
• The CHECK ENGINE malfunction indicator lamp (MI) circuit is shorted.
• TROUBLE SYMPTOM:
• Although MI comes on when the engine runs, trouble code is not shown on the Subaru select monitor
or OBD-II general scan tool display.
• WIRING DIAGRAM:
IGNITION
RELAY
37
34
36
38
B157
A8
B5
B10
COMBINATION
METER
A :
i10
B :
i11
B72
1 2
3 4
B157
1 2
3 4 9 14 15 16 19
10 17 20
5 6
11 12 13 18 21 22 23
7 8
1 CHECK HARNESS BETWEEN COMBINA-
TION METER AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Turn the ignition switch to ON.
Does the MI come on?
B72
4
i1
B36
B137
ECM
i11
1 2 3 4 5 6 7
8 9 10 11 12 13 14 15 16
24 25 26 29 34 35 36
27 30 37
28 31 32 33 38
Step
EN(H4DOSTC)-44
IGNITION
SWITCH
SBF-4
1
i10
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 29 30
B137
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 29 30 31
Value
MI illuminates.
BATTERY
No.5
SBF-1
E
B36
A1 A2 A4 A5 A6
A3
B1 B2 B4 B5 B6
B3
C2 C4 C5 C6
D1 D2 D4 D5 D6
C3
E1 E2 E4 E5 E6
F1 F6
G1 G6
H6
H1
I1 I6
J1 J6
K1 K6
L1 L2 L4 L5 L6
N3
M1 M2 M4 M5 M6
N2 N4 N5 N6
O3
O1 O2 O4 O5 O6
P3
P1 P2 P4 P5 P6
Yes
Repair the short Replace the ECM.
circuit in harness <Ref. to
between combina- FU(H4DOSTC)-
tion meter and 40, Engine Con-
ECM connector. trol Module.>
E
EN-00928
No