Subaru Legacy III (2000-2003 year). Manual — part 469

EN(H4DOSTC)-46

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 in inspection mode, the MI does not blink at a cycle of 3 Hz.

• WIRING DIAGRAM:

EN-00929

BATTERY

IGNITION
SWITCH

IGNITION
RELAY

SBF-4

SBF-1

No.5

B72

B36

B75

B76

E3

B22

B134

B137

B157

ECM

i1

E

E

E

1

4

16

1

1

37
34
36
38

B15

A5

i10

A :

i11

B :

A :

B :

B5

B10

COMBINATION
METER

B72

B22

B75

B134

B76

i10

B137

B157

B36

3 4

1 2

1

2

7

8

9

5

6

3

4

10 11 12

19 20 21
29 30 31

13 14 15 16 17

27 28

18

22 23 24 25 26

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

1 2 3 4

10 11 12

19 20 21

13

5

6

14 15

7

8 9

16 17

18

22

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

13 14 15 16

1
2

1
2

1
2

1
2

A8

A4

1 2 3
8 9 10

4

11 12 13 14 15 16

5 6 7

i11

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 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

EN(H4DOSTC)-47

ENGINE (DIAGNOSTICS)

ENGINE MALFUNCTION INDICATOR LAMP (MI)

Step

Value

Yes

No

1

CHECK STATUS OF CHECK ENGINE MAL-
FUNCTION INDICATOR LAMP (MI).
1) Turn the ignition switch to OFF.
2) Disconnect the test mode connector.
3) Turn the 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(H4DOSTC)-
40, CHECK
ENGINE MAL-
FUNCTION INDI-
CATOR LAMP
(MI) DOES NOT
COME ON.,
Engine Malfunc-
tion Indicator
Lamp (MI).>

2

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?

MI illuminates.

Repair the 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 the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the 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 the har-
ness and connec-
tor.

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 the poor
contact in ECM
connector.

Go to step 5.

5

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

between ECM and chassis ground.

Connector & terminal

(B134) No. 5 — Chassis ground:

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

1

Ω

Go to step 6.

Repair the 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 the poor
contact in ECM
connector.

Replace the ECM.
<Ref. to
FU(H4DOSTC)-
40, Engine Con-
trol Module.>

EN(H4DOSTC)-48

ENGINE (DIAGNOSTICS)

ENGINE MALFUNCTION INDICATOR LAMP (MI)

F: CHECK ENGINE MALFUNCTION INDICATOR LAMP (MI) REMAINS BLINK-

ING AT A CYCLE OF 3 HZ.

• DIAGNOSIS:

• Test mode connector circuit is shorted.

• TROUBLE SYMPTOM:

• MI blinks at a cycle of 3 Hz when the ignition switch is turned to ON.

• WIRING DIAGRAM:

EN-00929

BATTERY

IGNITION
SWITCH

IGNITION
RELAY

SBF-4

SBF-1

No.5

B72

B36

B75

B76

E3

B22

B134

B137

B157

ECM

i1

E

E

E

1

4

16

1

1

37
34
36
38

B15

A5

i10

A :

i11

B :

A :

B :

B5

B10

COMBINATION
METER

B72

B22

B75

B134

B76

i10

B137

B157

B36

3 4

1 2

1

2

7

8

9

5

6

3

4

10 11 12

19 20 21
29 30 31

13 14 15 16 17

27 28

18

22 23 24 25 26

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

1 2 3 4

10 11 12

19 20 21

13

5

6

14 15

7

8 9

16 17

18

22

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

13 14 15 16

1
2

1
2

1
2

1
2

A8

A4

1 2 3
8 9 10

4

11 12 13 14 15 16

5 6 7

i11

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 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

EN(H4DOSTC)-49

ENGINE (DIAGNOSTICS)

ENGINE MALFUNCTION INDICATOR LAMP (MI)

Step

Value

Yes

No

1

CHECK TEST MODE CONNECTOR.
1) Disconnect the test mode connector.
2) Turn the ignition switch to ON.

Does the MI flash on and off?

MI flashes.

Go to step 2.

System is in good
order.

NOTE:
MI blinks at a cycle
of 3 Hz when test
mode connector is
connected.

2

CHECK HARNESS BETWEEN ECM CON-
NECTOR AND ENGINE GROUNDING TER-
MINAL.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance of harness

between ECM connector and chassis
ground.

Connector & terminal

(B134) No. 5 — Chassis ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Replace the ECM.
<Ref. to
FU(H4DOSTC)-
40, Engine Con-
trol Module.>

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