Subaru Legacy IV (2008 year). Service manual — part 309

EN(H4DOTC)(diag)-57

Malfunction Indicator Light

ENGINE (DIAGNOSTICS)

16.Malfunction Indicator Light

A: PROCEDURE

1. Activation of malfunction indicator light. <Ref. to EN(H4DOTC)(diag)-58, ACTIVATION OF MALFUNCTION INDICATOR LIGHT,
Malfunction Indicator Light.>

p

2. Malfunction indicator light does not come on. <Ref. to EN(H4DOTC)(diag)-59, MALFUNCTION INDICATOR LIGHT DOES NOT
COME ON, Malfunction Indicator Light.>

p

3. Malfunction indicator light does not go off. <Ref. to EN(H4DOTC)(diag)-61, MALFUNCTION INDICATOR LIGHT DOES NOT
GO OFF, Malfunction Indicator Light.>

p

4. Malfunction indicator light does not blink. <Ref. to EN(H4DOTC)(diag)-62, MALFUNCTION INDICATOR LIGHT DOES NOT
BLINK, Malfunction Indicator Light.>

p

5. Malfunction indicator light remains blinking. <Ref. to EN(H4DOTC)(diag)-64, MALFUNCTION INDICATOR LIGHT REMAINS
BLINKING, Malfunction Indicator Light.>

EN(H4DOTC)(diag)-58

Malfunction Indicator Light

ENGINE (DIAGNOSTICS)

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 diagnostics of the malfunction indicator
light circuit or the combination meter circuit. <Ref.
to EN(H4DOTC)(diag)-59, MALFUNCTION INDI-
CATOR LIGHT DOES NOT COME ON, Malfunc-
tion Indicator Light.>

2) After starting the engine, the malfunction indica-
tor light goes out. If it does not go off, either the en-
gine or emission control system has malfunction.

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

(1) When the ignition switch is turned to ON
(engine OFF), the malfunction indicator light il-
luminates.
(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 DTC

(2) Trouble occurs

(3) ON

(4) OFF

(5) Ignition switch ON

(6) Engine start

EN-05079

(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(H4DOTC)(diag)-59

Malfunction Indicator Light

ENGINE (DIAGNOSTICS)

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 illuminate.
WIRING DIAGRAM:

EN-05122

SBF-6

MAIN SBF

No.5

B72

B38

B136

ECM

i3

E

3

11

i10

3

16

8

B72

i10

B38

COMBINATION
METER

IGNITION SWITCH

BATTERY

B136

2

1

3 4

6 7 8 9 10

22

21

20

19

18

17

16

15

14

13

12

11

5

1

3

4 5 6

2

1 2 3 4

5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

1

16

10 11 12 13 14 15

25

24

30

9

8

7

17 18 19 20
28

21 22 23

29

32

31

1

2

3

4

5

6

27

26

33 34 35

EN(H4DOTC)(diag)-60

Malfunction Indicator Light

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

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

Connector & terminal

(B136) No. 11 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Go to step 5.

Go to step 2.

2

CHECK HARNESS BETWEEN ECM AND
COMBINATION METER CONNECTOR.
1) Turn the ignition switch to OFF.
2) Remove the combination meter. <Ref. to
IDI-22, Combination Meter.>
3) Disconnect the connector from the ECM
and combination meter.
4) Measure the resistance of harness between
ECM and combination meter connector.

Connector & terminal

(B136) No. 11 — (i10) No. 16:

Is the resistance less than 1

:? Go to step 3.

Repair the harness
and connector.

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

3

CHECK POOR CONTACT.
Check for poor contact of combination meter
connector.

Is there poor contact in combi-
nation meter connector?

Repair the poor
contact of combi-
nation meter con-
nector.

Go to step 4.

4

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 (–):

Is the voltage 10 V or more?

Replace the com-
bination meter
board. <Ref. to IDI-
22, Combination
Meter.>

Check the follow-
ing item and repair
if necessary.

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

5

CHECK POOR CONTACT.
Check for poor connection by shaking or pulling
ECM connector and harness.

Does the malfunction indicator
light illuminate?

Repair the poor
contact of ECM
connector.

Go to step 6.

6

CHECK ECM CONNECTOR.
Check the connection of ECM connector.

Is the ECM connector correctly
connected?

Replace the ECM.
<Ref. to
FU(H4DOTC)-52,
Engine Control
Module (ECM).>

Repair the connec-
tion of ECM con-
nector.