Subaru Legacy III (2000-2003 year). Manual — part 111

EN(H4SO)-56

ENGINE (DIAGNOSTICS)

ENGINE MALFUNCTION INDICATOR LAMP (MI)

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 engine runs, trouble code is not shown on Subaru select monitor or OBD-
II general scan tool display.

• WIRING DIAGRAM:

EN-01116

LHD MODEL : 10
RHD MODEL : 37

1

*

2

*

3

*

4

*

5

*

LHD MODEL : 11
RHD MODEL : 34

LHD MODEL : 13
RHD MODEL : 36

LHD MODEL : 9
RHD MODEL : 38

LHD MODEL : 12
RHD MODEL : 15

5

*

IGNITION
RELAY

SBF-4

No. 5

SBF-1

4

1

B157

B72

B134

B36

i1

IGNITION
SWITCH

B134

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 32 33

34 35

B72

3 4

1 2

BATTERY

28

ECM

COMBINATION
METER

3

i12

A4

i12

1 2 3

4 5 6

7 8 9 10 11 12 13 14

B157

10

11 12 13

14 15 16

17
18

19

20

21 22 23

24 25 26

27
28

29

30

31 32 33

34 35 36

37
38

1

2

9

3

4

5

6

7

8

B36

B4 B5 B6

A4 A5 A6

C5 C6

F6

D4 D5 D6

F1

H1

C4

G6

G1

C2

K1

M1 M2

K6

L1

D1 D2

A1 A2
B1 B2

I6

J6

L2

I1

J1

H6

M4 M5 M6

L4 L5 L6

N5 N6

O4 O5 O6

N4

P4 P5

N2

O1 O2

P1 P2

N3

O3

P3

P6

A3

B3

C3

E4 E5 E6

E1 E2

1

*

2

*

3

*

4

*

EN(H4SO)-57

ENGINE (DIAGNOSTICS)

ENGINE MALFUNCTION INDICATOR LAMP (MI)

Step

Value

Yes

No

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 MI come on?

MI illuminates.

Repair short circuit
in harness
between combina-
tion meter and
ECM connector.

Replace ECM.
<Ref. to
FU(H4SO)-45,
Engine Control
Module.>

EN(H4SO)-58

ENGINE (DIAGNOSTICS)

ENGINE MALFUNCTION INDICATOR LAMP (MI)

E: CHECK ENGINE MALFUNCTION INDICATOR LAMP (MI) DOES NOT BLINK

AT A CYCLE OF 3 HZ.

• DIAGNOSIS:

• The CHECK ENGINE malfunction indicator lamp (MI) circuit is open or shorted.
• Test mode connector circuit is in open.

• TROUBLE SYMPTOM:

• When inspection mode, MI does not blink at a cycle of 3 Hz.

• WIRING DIAGRAM:

EN-01117

1

*

5

*

2

*

3

*

4

*

LHD MODEL : 10
RHD MODEL : 37

1

*

2

*

3

*

4

*

5

*

LHD MODEL : 11
RHD MODEL : 34

LHD MODEL : 13
RHD MODEL : 36

LHD MODEL : 9
RHD MODEL : 38

LHD MODEL : 12
RHD MODEL : 15

SBF-4

No. 5

SBF-1

4

1

B72

IGNITION
SWITCH

BATTERY

B72

3 4

1 2

B75

B76

1
2

1
2

1

1

B75

B76

B22

E3

A28

C3

B136

B134

ECM

16

B22

1 2 3 4
5 6 7 8
9 10 11 12

13 14 15 16

IGNITION
RELAY

B157

B36

i1

COMBINATION
METER

A:

C:

3

i12

A4

i12

1 2 3

4 5 6

7 8 9 10 11 12 13 14

B134

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 32 33

34 35

B157

10

11 12 13

14 15 16

17
18

19

20

21 22 23

24 25 26

27
28

29

30

31 32 33

34 35 36

37
38

1

2

9

3

4

5

6

7

8

B136

B4 B5 B6

A4 A5 A6

C5 C6

F6

D4 D5 D6

F1

H1

C4

G6

G1

C2

K1

M1 M2

K6

L1

D1 D2

A1 A2
B1 B2

I6

J6

L2

I1

J1

H6

M4 M5 M6

L4 L5 L6

N5 N6

O4 O5 O6

N4

P4 P5

N2

O1 O2

P1 P2

N3

O3

P3

P6

A3

B3

C3

E4 E5 E6

E1 E2

5

4

6 7

8

2

1

9

3

10

22

23

11 12 13 14 15

24 25

26 27

16 17 18

28 29

19 20

21

30

B136

EN(H4SO)-59

ENGINE (DIAGNOSTICS)

ENGINE MALFUNCTION INDICATOR LAMP (MI)

Step

Value

Yes

No

1

CHECK STATUS OF CHECK ENGINE MAL-
FUNCTION INDICATOR LAMP (MI).
1) Turn ignition switch to OFF.
2) Disconnect test mode connector.
3) Turn ignition switch to ON. (engine OFF)

Does the MI come on?

MI illuminates.

Go to step 2.

Repair the MI cir-
cuit. <Ref. to
EN(H4SO)-52,
CHECK ENGINE
MALFUNCTION
INDICATOR
LAMP (MI) DOES
NOT COME ON.,
Engine Malfunc-
tion Indicator
Lamp (MI).>

2

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 MI come on?

MI illuminates.

Repair ground
short circuit in har-
ness between
combination meter
and ECM connec-
tor.

Go to step 3.

3

CHECK HARNESS BETWEEN TEST MODE
CONNECTOR AND CHASSIS GROUND.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Measure resistance of harness between

test mode connector and chassis ground.

Connector & terminal

(B76) No. 1 — Chassis ground:

Is the measured value less than the speci-
fied value?

1

Ω

Go to step 4.

Repair harness
and connector.

NOTE:
In this case, repair
the following:
• Open circuit in
harness between
test mode connec-
tor and chassis
ground

4

CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?

There is poor contact.

Repair poor con-
tact in ECM con-
nector.

Go to step 5.

5

CHECK HARNESS BETWEEN ECM AND
TEST MODE CONNECTOR.
1) Connect test mode connector.
2) Measure resistance of harness between

ECM and chassis ground.

Connector & terminal

(B136) No. 3 — Chassis ground:

Is the measured value less than the speci-
fied value?

1

Ω

Go to step 6.

Repair open circuit
in harness
between ECM and
test mode connec-
tor.

6

CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?

There is poor contact.

Repair poor con-
tact in ECM con-
nector.

Replace ECM.
<Ref. to
FU(H4SO)-45,
Engine Control
Module.>