Subaru Legacy (2005 year). Service manual — part 435

EN(H6DO)(diag)-53

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

16.Diagnostics for Engine Starting Failure

A: PROCEDURE

1. Check for fuel amount.

↓

2. Inspection of starter motor circuit. <Ref. to EN(H6DO)(diag)-54, STARTER MOTOR CIRCUIT, Diagnostics for Engine Starting
Failure.>

↓

3. Inspection of ECM power supply and ground line. <Ref. to EN(H6DO)(diag)-57, CHECK POWER SUPPLY AND GROUND
LINE OF ENGINE CONTROL MODULE (ECM), Diagnostics for Engine Starting Failure.>

↓

4. Inspection of ignition control system. <Ref. to EN(H6DO)(diag)-60, IGNITION CONTROL SYSTEM, Diagnostics for Engine
Starting Failure.>

↓

5. Inspection of fuel pump circuit. <Ref. to EN(H6DO)(diag)-62, FUEL PUMP CIRCUIT, Diagnostics for Engine Starting Failure.>

↓

6. Inspection of fuel injector circuit. <Ref. to EN(H6DO)(diag)-64, FUEL INJECTOR CIRCUIT, Diagnostics for Engine Starting Fail-
ure.>

EN(H6DO)(diag)-54

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

B: STARTER MOTOR CIRCUIT

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H6DO)(diag)-41,
OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H6DO)(diag)-34, PROCEDURE,
Inspection Mode.>.
WIRING DIAGRAM:

EN-03489

D8

B32

No.21

B225

MAIN SBF

SBF-6

E

1

3

2

4

ECM

B137

D:

B135

B:

B72

B14

M

2

3

B225

B137

B72

D:

B135

B:

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

39 40

37
38

1

2

9

3

4

5

6

7

8

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

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

32 33

34 35

1

3

4 5 6

2

BATTERY

IGNITION
SWITCH

STARTER
RELAY

STARTER MOTOR

*

*

*

*

*

LHD: 15
RHD: 16

1

*

LHD: 16
RHD: 15

2

*

LHD: 13
RHD: 14

3

*

LHD: 14
RHD: 13

4

EN(H6DO)(diag)-55

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

Step

Check

Yes

No

1

CHECK BATTERY.
Check the battery voltage.

Is the voltage more than 12 V? Go to step 2.

Charge or replace
the battery.

2

CHECK OPERATION OF STARTER MOTOR. Does the starter motor oper-

ate?

Go to step 3.

Go to step 4.

3

CHECK DTC.

Is DTC displayed? <Ref. to
EN(H6DO)(diag)-33, OPERA-
TION, Read Diagnostic Trouble
Code (DTC).>

Inspect the rele-
vant DTC using
List of Diagnostic
Trouble Code
(DTC). <Ref. to
EN(H6DO)(diag)-
66, List of Diag-
nostic Trouble
Code (DTC).>

Repair the poor
contact in ECM
connector.

4

CHECK INPUT SIGNAL OF STARTER MO-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from starter
motor.
3) Turn the ignition switch to START.
4) Measure the power supply voltage between
starter motor connector terminal and engine
ground.

Connector & terminal

(B14) No. 1 (+) — Engine ground (

−

):

NOTE:

• For AT model, place the select lever in “P” or
“N” range.
• For MT model, depress the clutch pedal.

Is the voltage more than 10 V? Check the starter

motor. <Ref. to
SC(H4SO 2.0)-6,
Starter.>

Go to step 5.

5

CHECK HARNESS BETWEEN BATTERY
AND IGNITION SWITCH CONNECTOR.
1) Disconnect the connector from ignition
switch.
2) Measure the power supply voltage between
ignition switch connector and chassis ground.

Connector & terminal

(B72) No. 3 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Go to step 6.

Repair the open
circuit of harness
between ignition
switch and bat-
tery, and check
fuse SBF No. 6
and MAIN SBF.

6

CHECK IGNITION SWITCH.
1) Disconnect the connector from ignition
switch.
2) Measure the resistance between ignition
switch terminals after turning the ignition
switch to START position.

Terminal

No. 2 — No. 3:

Is the resistance less than 5
Ω?

Go to step 7.

Replace the igni-
tion switch.

7

CHECK INPUT VOLTAGE OF STARTER RE-
LAY.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from starter relay.
3) Connect the connector to ignition switch.
4) Measure the input voltage between starter
relay connector and chassis ground after turn-
ing the ignition switch to START position.

Connector & terminal
LHD model

(B225) No. 13 (+) — Chassis ground (

−

):

(B225) No. 15 (+) — Chassis ground (

−

):

RHD model

(B225) No. 14 (+) — Chassis ground (

−

):

(B225) No. 16 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Go to step 8.

Repair the open
circuit of harness
between starter
relay and ignition
switch.

EN(H6DO)(diag)-56

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

8

CHECK STARTER RELAY.
1) Connect the battery to starter relay termi-
nals No. 15 and No. 16.
2) Measure the resistance between starter
relay terminals.

Terminal

No. 13 — No. 14:

Is the resistance less than 1
Ω?

Go to step 9.

Replace the
starter relay.

9

CHECK INPUT VOLTAGE OF ECM.
1) Turn the ignition switch to OFF.
2) Connect the connector to starter relay.
3) Disconnect the connector from ECM.
4) Turn the ignition switch to START.
5) Measure the voltage between ECM and
chassis ground.

Connector & terminal

(B135) No. 32 (+) — Chassis ground (

−

):

(B137) No. 8 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Replace the ECM.

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

Repair the open or
ground short cir-
cuit of harness
between ECM and
starter relay.

Step

Check

Yes

No