Subaru Legacy III (2000-2003 year). Manual - part 467

EN(H4DOSTC)-38

ENGINE (DIAGNOSTICS)

ENGINE MALFUNCTION INDICATOR LAMP (MI)

14.Engine Malfunction Indicator Lamp (MI)

A: PROCEDURE

1.

Activation of check engine malfunction indicator lamp (MI). <Ref. to EN(H4DOSTC)-39, ACTIVATION OF CHECK ENGINE 

MALFUNCTION INDICATOR LAMP (MI), Engine Malfunction Indicator Lamp (MI).>

↓

2.

Check that engine malfunction indicator lamp (MI) does not come on. <Ref. to EN(H4DOSTC)-40, CHECK ENGINE MAL-

FUNCTION INDICATOR LAMP (MI) DOES NOT COME ON., Engine Malfunction Indicator Lamp (MI).>

↓

3.

Check that engine malfunction indicator lamp (MI) does not go off. <Ref. to EN(H4DOSTC)-44, CHECK ENGINE MALFUNC-

TION INDICATOR LAMP (MI) DOES NOT GO OFF., Engine Malfunction Indicator Lamp (MI).>

↓

4.

Check that engine malfunction indicator lamp (MI) does not blink at a cycle of 3 Hz. <Ref. to EN(H4DOSTC)-46, CHECK 

ENGINE MALFUNCTION INDICATOR LAMP (MI) DOES NOT BLINK AT A CYCLE OF 3 HZ., Engine Malfunction Indicator Lamp 
(MI).>

↓

5.

Check that engine malfunction indicator lamp (MI) remains blinking at a cycle of 3 Hz. <Ref. to EN(H4DOSTC)-48, CHECK 

ENGINE MALFUNCTION INDICATOR LAMP (MI) REMAINS BLINKING AT A CYCLE OF 3 HZ., Engine Malfunction Indicator 
Lamp (MI).>

EN(H4DOSTC)-39

ENGINE (DIAGNOSTICS)

ENGINE MALFUNCTION INDICATOR LAMP (MI)

B: ACTIVATION OF CHECK ENGINE 

MALFUNCTION INDICATOR 
LAMP (MI)

1) When the ignition switch is turned to ON (engine
OFF), the CHECK ENGINE malfunction indicator
lamp (MI) in the combination meter illuminates.

NOTE:
If the MI does not illuminate, perform diagnostics of
the CHECK ENGINE light circuit or the combination
meter circuit. <Ref. to EN(H4DOSTC)-40, CHECK
ENGINE MALFUNCTION INDICATOR LAMP (MI)
DOES NOT COME ON., Engine Malfunction Indi-
cator Lamp (MI).>

2) After starting the engine, the MI goes out. If it
does not, either the engine or emission control sys-
tem is malfunctioning.

3) If the diagnosis system senses a misfire which
could damage the catalyzer, the MI will blink at a
cycle of 1 Hz.

4) When the ignition switch is turned to ON (engine
OFF) or to “START” with the test mode connector
connected, the MI blinks at a cycle of 3 Hz.

EN-01001

EN-00196

a)  No trouble

b)  Trouble occurs.

ON

MIL

OFF

ON

ON

MIL

OFF

Ignition
switch

Engine
start

EN-00197

ON

MIL

OFF

ON

Ignition
switch

Engine
start

Misfire
start

1 sec.

EN-00198

ON

MIL

OFF

ON

Ignition
switch

1 sec.

EN(H4DOSTC)-40

ENGINE (DIAGNOSTICS)

ENGINE MALFUNCTION INDICATOR LAMP (MI)

C: CHECK ENGINE MALFUNCTION INDICATOR LAMP (MI) DOES NOT COME 

ON.

• DIAGNOSIS:

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

• TROUBLE SYMPTOM:

• When the ignition switch is turned ON (engine OFF), the MI does not come on.

• WIRING DIAGRAM:

EN-00928

BATTERY

IGNITION
SWITCH

IGNITION
RELAY

SBF-4

SBF-1

No.5

B72

B72

B36

B137

B157

ECM

i1

E

E

1

4

37
34
36
38

15

i10

A :

i11

B :

i11

i10

B137

B157

B5

B10

COMBINATION
METER

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

A4

A8

1 2 3
8 9 10

4

11 12 13 14 15 16

5 6 7

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

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

EN(H4DOSTC)-41

ENGINE (DIAGNOSTICS)

ENGINE MALFUNCTION INDICATOR LAMP (MI)

Step

Value

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

(B137) No. 15 (+) — Chassis ground (

−−−−

):

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

1 V

Go to step 4.

Go to step 2.

2

CHECK POOR CONTACT.
Does the MI come on when shaking or pulling 
ECM connector and harness?

MI illuminates.

Repair the poor 
contact in ECM 
connector.

Go to step 3.

3

CHECK ECM CONNECTOR.
Is the ECM connector correctly connected?

Connected.

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

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 Assembly.>

3) Disconnect the connector from ECM and 

combination meter.

4) Measure the resistance of harness 

between ECM and combination meter con-
nector.

Connector & terminal

(B137) No. 15 — (i11) No. 10:

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

1 

Ω

Go to step 5.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following:
• Open circuit in 
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 combination meter 
connector?

There is poor contact.

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

Go to step 6.