Subaru Legacy (2005 year). Manual - part 433

EN(H6DO)(diag)-45

ENGINE (DIAGNOSTICS)

Malfunction Indicator Light

B: ACTIVATION OF MALFUNCTION 

INDICATOR LIGHT

1) When the ignition switch is turned to ON (engine
OFF), the malfunction indicator light (A) in the com-
bination meter illuminates.

NOTE:
If the malfunction indicator light does not illuminate,
perform the diagnosis of malfunction indicator light
circuit or the combination meter circuit. <Ref. to
EN(H6DO)(diag)-46, MALFUNCTION INDICATOR
LIGHT DOES NOT COME ON, Malfunction Indica-
tor Light.>

2) After starting the engine, the malfunction indica-
tor light goes out. If it does not, either the engine or
emission control system is malfunctioning.

3) Turn the ignition switch to OFF and connect the
test mode connector.

(1) When the ignition switch is turned to ON
(engine OFF), the malfunction indicator light illu-
minates.
(2) After the engine starts, malfunction indicator
light blinks in a cycle of 0.5 Hz. (during diagno-
sis)

(3) Malfunction indicator light blinks at a cycle of
3 Hz after diagnosis if there is no trouble. Mal-
function indicator light illuminates if faulty.

(1) No faulty

(2) Trouble occurs

(3) ON

(4) OFF

(5) Ignition switch ON

(6) Engine start

EN-01984

(A)

EN-01679

(1)

(2)

(5)

(6)

(3)

(4)

(3)

(4)

(1) ON

(2) OFF

(3) Ignition switch ON

(4) 1 second

EN-01681

(2)

(1)

(4)

(3)

EN(H6DO)(diag)-46

ENGINE (DIAGNOSTICS)

Malfunction Indicator Light

C: MALFUNCTION INDICATOR LIGHT DOES NOT COME ON

DIAGNOSIS:
The malfunction indicator light circuit is open or shorted.
TROUBLE SYMPTOM:
When the ignition switch is turned to ON (engine OFF), malfunction indicator light does not come on.
WIRING DIAGRAM:

Step

Check

Yes

No

1

CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM con-
nector and chassis ground.

Connector & terminal

(B134) No. 17 (+) — Chassis ground (

−

):

Is the voltage less than 1 V?

Go to step 4.

Go to step 2.

2

CHECK POOR CONTACT.
Check for poor connection by shaking or pull-
ing ECM connector and harness.

Does the malfunction indicator 
light illuminate?

Repair the poor 
contact in ECM 
connector.

Go to step 3.

EN-03487

BATTERY

3

B72

i3

B38

B134

IGNITION
SWITCH

COMBINATION
METER

i10

SBF-6

6

17

ECM

4

B72

8

MAIN SBF

No.5

16

E

3

1

3

4 5 6

2

B134

5

6

7

8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26 27

28

16 17

18 19 20 21

33 34

29

32

30 31

B38

1 2 3 4

5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

i10

2

1

3 4

6 7 8 9 10

22

21

20

19

18

17

16

15

14

13

12

11

5

EN(H6DO)(diag)-47

ENGINE (DIAGNOSTICS)

Malfunction Indicator Light

3

CHECK ECM CONNECTOR.
Check the connection of ECM connector.

Is the ECM connector correctly 
connected?

Replace the ECM. 
<Ref. to 
FU(H6DO)-34, 
Engine Control 
Module (ECM).>

Repair the con-
nection of ECM 
connector.

4

CHECK HARNESS BETWEEN COMBINA-
TION METER AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Remove the combination meter. <Ref. to 
IDI-15, Combination Meter.>
3) Disconnect the connector from ECM and 
combination meter.
4) Measure the resistance of harness 
between ECM and combination meter connec-
tor.

Connector & terminal

(B134) No. 17 — (i10) No. 16:

Is the resistance less than 1 
Ω?

Go to step 5.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following:
• Open circuit of 
harness between 
ECM and combi-
nation meter con-
nector
• Poor contact in 
coupling connector

5

CHECK POOR CONTACT.
Check poor contact in combination meter con-
nector.

Is there poor contact in combi-
nation meter connector?

Repair poor con-
tact in combination 
meter connector.

Go to step 6.

6

CHECK HARNESS BETWEEN COMBINA-
TION METER AND IGNITION SWITCH CON-
NECTOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between combination 
meter connector and chassis ground.

Connector & terminal

(i10) No. 3 (+) — Chassis ground (

−

):

(i10) No. 4 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Replace the meter 

case assembly of 
combination 
meter. <Ref. to IDI-
15, Combination 
Meter.>

Check the follow-
ing and repair if 
necessary.

NOTE:
• Blown out fuse 
(No. 5)
• Open or short 
circuit of harness 
between fuse (No. 
5) and battery ter-
minal
• Poor contact in 
ignition switch con-
nector

Step

Check

Yes

No

EN(H6DO)(diag)-48

ENGINE (DIAGNOSTICS)

Malfunction Indicator Light

D: MALFUNCTION INDICATOR LIGHT DOES NOT GO OFF.

DIAGNOSIS:
The malfunction indicator light circuit is shorted.
TROUBLE SYMPTOM:
Although malfunction indicator light comes on when the engine runs, DTC is not shown on the Subaru Select
Monitor display.
WIRING DIAGRAM:

Step

Check

Yes

No

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 malfunction indicator 
light illuminate?

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

Replace the ECM. 
<Ref. to 
FU(H6DO)-34, 
Engine Control 
Module (ECM).>

EN-03487

BATTERY

3

B72

i3

B38

B134

IGNITION
SWITCH

COMBINATION
METER

i10

SBF-6

6

17

ECM

4

B72

8

MAIN SBF

No.5

16

E

3

1

3

4 5 6

2

B134

5

6

7

8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26 27

28

16 17

18 19 20 21

33 34

29

32

30 31

B38

1 2 3 4

5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

i10

2

1

3 4

6 7 8 9 10

22

21

20

19

18

17

16

15

14

13

12

11

5