Subaru Legacy IV (2008 year). Service manual - part 335

 

  Index      Subaru     Subaru Legacy IV - service and repair manual 2008 year

 

Search            

 

 

 

 

 

 

 

  

 

Content   ..  333  334  335  336   ..

 

 

Subaru Legacy IV (2008 year). Service manual - part 335

 

 

EN(H4DOTC)(diag)-161

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and 
electronic throttle control.
3) Measure the resistance of harness between 
ECM and electronic throttle control connector.

Connector & terminal

(B134) No. 28 — (E57) No. 4:
(B134) No. 29 — (E57) No. 3:

Is the resistance less than 1 

:? Go to step 2.

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and electron-
ic throttle control
connector
• Poor contact of
coupling connector

2

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Connect the ECM.
2) Measure the resistance between electronic 
throttle control connector and engine ground.

Connector & terminal

(E57) No. 3 — Engine ground:

Is the resistance less than 5 

:? Go to step 3.

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit of
harness between
ECM and engine
ground
• Poor contact in
ECM connector
• Poor contact of
coupling connector

3

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to ON.
2) Measure the voltage between electronic 
throttle control connector and engine ground.

Connector & terminal

(E57) No. 4 (+) — Engine ground (–):

Is the voltage 4.85 V or more?

Repair the short 
circuit to power in 
the harness 
between ECM and 
electronic throttle 
control connector.

Go to step 4.

4

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance between ECM con-
nectors.

Connector & terminal

(B134) No. 19 — (B134) No. 28:

Is the resistance 1 M

: or 

more?

Repair poor con-
tact of the elec-
tronic throttle 
control connector. 
Replace the elec-
tronic throttle con-
trol if defective. 
<Ref. to 
FU(H4DOTC)-14, 
Throttle Body.>

Repair the short 
circuit to power in 
the harness 
between ECM and 
electronic throttle 
control connector.

EN(H4DOTC)(diag)-162

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

AO:DTC P0230 FUEL PUMP PRIMARY CIRCUIT

DTC DETECTING CONDITION:
• Two consecutive driving cycles with fault
• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-74, DTC P0230 FUEL PUMP PRIMARY CIRCUIT, Di-
agnostic Trouble Code (DTC) Detecting Criteria.>

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-
52, OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H4DOTC)(diag)-43, PRO-
CEDURE, Inspection Mode.>.
WIRING DIAGRAM:

EN-05083

E

E

M

10

7

6

5

6

3

5

No.11

B362

R122

B135

B:

B136

C:

R58

B97

7

B33

C12

1

2

9

8

5

19

8

R1

20

R1

B97

R46

R67

FUEL PUMP
CONTROL UNIT

FUEL
PUMP

ECM

BATTERY

FUEL PUMP
RELAY

B135

B136

B362

R58

2

5

4
6

1
3

B:

C:

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

29 30 31

32 33

34 35

R122

3 4

1 2
5

8 9 10

6 7

5
6

7 8

3
4

1 2

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

B97

R67

1 2 3 4

5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

1

2

3 4 5 6

EN(H4DOTC)(diag)-163

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK POWER SUPPLY CIRCUIT TO FUEL 
PUMP CONTROL UNIT.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from fuel pump 
control unit.
3) Turn the ignition switch to ON.
4) Measure the voltage between fuel pump 
control unit and chassis ground.

Connector & terminal

(R122) No. 10 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Go to step 2.

Repair the power 
supply circuit.

NOTE:
In this case, repair
the following item:
• Open or ground
short circuit of har-
ness between fuel
pump relay and
fuel pump control
unit
• Poor contact of
fuel pump control
unit connector
• Poor contact of
fuel pump relay
connector

2

CHECK GROUND CIRCUIT OF FUEL PUMP 
CONTROL UNIT.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness between 
fuel pump control unit and chassis ground.

Connector & terminal

(R122) No. 5 — Chassis ground:

Is the resistance less than 5 

:? Go to step 3.

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit be-
tween fuel pump
control unit and
chassis ground
• Poor contact of
fuel pump control
unit connector

3

CHECK HARNESS BETWEEN FUEL PUMP 
CONTROL UNIT AND FUEL PUMP CONNEC-
TOR.
1) Disconnect the connector from fuel pump.
2) Measure the resistance of harness between 
fuel pump control unit and fuel pump connector.

Connector & terminal

(R122) No. 7 — (R58) No. 5:
(R122) No. 6 — (R58) No. 6:

Is the resistance less than 1 

:? Go to step 4.

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
fuel pump control
unit and fuel pump
• Poor contact of
coupling connector

4

CHECK HARNESS BETWEEN FUEL PUMP 
CONTROL UNIT AND FUEL PUMP CONNEC-
TOR.
Measure the resistance between fuel pump 
control unit and chassis ground.

Connector & terminal

(R122) No. 7 — Chassis ground:
(R122) No. 6 — Chassis ground:

Is the resistance 1 M

: or 

more?

Go to step 5.

Repair the ground 
short circuit of har-
ness between fuel 
pump control unit 
and fuel pump.

5

CHECK HARNESS BETWEEN ECM AND 
FUEL PUMP CONTROL UNIT.
1) Disconnect the connectors from ECM.
2) Measure the resistance of harness between 
ECM and fuel pump control unit.

Connector & terminal

(B135) No. 33 — (R122) No. 9:
(B136) No. 12 — (R122) No. 8:

Is the resistance less than 1 

:? Go to step 6.

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit be-
tween ECM and
fuel pump control
unit
• Poor contact of
coupling connector

EN(H4DOTC)(diag)-164

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

6

CHECK HARNESS BETWEEN ECM AND 
FUEL PUMP CONTROL UNIT.
Measure the resistance between fuel pump 
control unit and chassis ground.

Connector & terminal

(R122) No. 9 — Chassis ground:
(R122) No. 8 — Chassis ground:

Is the resistance 1 M

: or 

more?

Go to step 7.

Repair the ground 
short circuit of har-
ness between 
ECM and fuel 
pump control unit.

7

CHECK POOR CONTACT.
Check for poor contact of ECM and fuel pump 
control unit connector.

Is there poor contact in ECM or 
fuel pump control unit connec-
tor?

Repair the poor 
contact of ECM or 
fuel pump control 
unit connector.

Go to step 8.

8

CHECK EXPERIENCE OF RUNNING OUT OF 
FUEL.

Has the vehicle experienced 
running out of fuel?

Finish the diagno-
sis.

NOTE:
DTC may be re-
corded as a result
of fuel pump idling
while running out
of fuel.

Replace the fuel 
pump control unit. 
<Ref. to 
FU(H4DOTC)-56, 
Fuel Pump Control 
Unit.>

Step

Check

Yes

No

 

 

 

 

 

 

 

Content   ..  333  334  335  336   ..