Subaru Legacy III (2000-2003 year). Service manual — part 470

EN(H4DOSTC)-50

ENGINE (DIAGNOSTICS)

ENGINE MALFUNCTION INDICATOR LAMP (MI)

MEMO:

EN(H4DOSTC)-51

ENGINE (DIAGNOSTICS)

DIAGNOSTICS FOR ENGINE STARTING FAILURE

15.Diagnostics for Engine Starting Failure

A: PROCEDURE

1.

Inspection of starter motor circuit. <Ref. to EN(H4DOSTC)-52, STARTER MOTOR CIRCUIT, Diagnostics for Engine Starting

Failure.>

↓

2.

Inspection of ECM power supply and ground line. <Ref. to EN(H4DOSTC)-56, CONTROL MODULE POWER SUPPLY AND

GROUND LINE, Diagnostics for Engine Starting Failure.>

↓

3.

Inspection of fuel pump circuit. <Ref. to EN(H4DOSTC)-60, FUEL PUMP CIRCUIT, Diagnostics for Engine Starting Failure.>

EN(H4DOSTC)-52

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(H4DOSTC)-
35, Clear Memory Mode.> and INSPECTION MODE <Ref. to EN(H4DOSTC)-33, Inspection Mode.> .
• WIRING DIAGRAM:

EN-00930

BATTERY

IGNITION

SWITCH

STARTER
MOTOR

SBF-4

SBF-1

B72

B72

B14

B134 ECM

E

E

1

3

16

3 4

1 2

B134

B12

T7

1 2 3 4

10 11 12

19 20 21

13

5

6

14 15

7

8 9

16 17

18

22

12

INHIBITOR SWITCH

7

P

R

N

D

3

2

1

12

11

T7

T3

B12

AT

AT

MT

MT

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

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

EN(H4DOSTC)-53

ENGINE (DIAGNOSTICS)

DIAGNOSTICS FOR ENGINE STARTING FAILURE

Step

Value

Yes

No

1

CHECK OPERATION OF STARTER MOTOR.
Does the starter motor operate when the
switch starts?

Operates.

Go to step 2.

Go to step 3.

2

CHECK DTC.
Is DTC displayed?

DTC is indicated.

Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
EN(H4DOSTC)-
62, List of Diag-
nostic Trouble
Code (DTC).>

Repair poor con-
tact in ECM con-
nector.

3

CHECK INPUT SIGNAL FOR STARTER MO-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from starter

motor.

3) Turn the ignition switch to ST.
4) Measure the power supply voltage between

starter motor connector terminal and
engine ground.

Connector & terminal

(B14) No. 1 (+) — Engine ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

NOTE:

On AT vehicles, place the selector lever in the
“P” or “N” position.

10 V

Go to step 4.

Go to step 5.

4

CHECK GROUND CIRCUIT OF STARTER
MOTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the terminal from starter motor.
3) Measure the resistance of ground cable

between ground cable terminal and engine
ground.
Is the measured value less than the speci-
fied value?

5

Ω

Check the starter
motor. <Ref. to
SC(H4DOSTC)-6,
Starter.>

Repair the open
circuit of ground
cable.

5

CHECK HARNESS BETWEEN BATTERY
AND IGNITION SWITCH CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ignition

switch.

3) Measure the power supply voltage between

ignition switch connector and chassis
ground.

Connector & terminal

(B72) No. 1 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

10 V

Go to step 6.

Repair the open
circuit in harness
between ignition
switch and battery,
and check fuse
SBF No. 4 and
SBF No. 1.

6

CHECK IGNITION SWITCH.
1) Disconnect the connector from ignition

switch.

2) Measure the resistance between ignition

switch terminals while turning ignition
switch to the “ST” position.

Terminals

No. 1 — No. 3:

Is the measured value less than specified
value?

5

Ω

Go to step 7.

Replace the igni-
tion switch.