Subaru Legacy III (2000-2003 year). Manual - part 506

EN(H4DOSTC)-194

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

AW:DTC P1230 — FUEL PUMP CONTROLLER —

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4DOSTC)-35, 
OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOSTC)-33, Inspection 
Mode.> .
• WIRING DIAGRAM:

EN-00932

B134

B136

B46

R122

E

E

M

10

7

6

FUEL  PUMP
RELAY

FUEL  PUMP
CONTROLLER

FUEL
PUMP

SBF-5

B46

R122

B134

A :

B136

C :

R15

R57

R58

R2

ECM

B98

B99

R58

B99

R3

BATTERY

1

3

5

4

A13

C16

3 4

1 2

8 9 10 11

12 13 14 15 16 17 18 19 20 21 22 23 24

5

6 7

3 4

1 2

1 2

3 4

5 6 7 8 9 10

1 2 3 4

10 11 12

19 20 21

13

5

6

14 15

7

8 9

16 17

18

22

1 2

7

8 9

5

6

3

4

10 11 12
19 20 21

13 14 15 16

17 18

22 23 24

2

4

2

1

9

8

5

14

16

1

2

3 4 5 6

R57

R3

R2

2 3 4 5

6 7 8 9

11 12 13 14

17 18 19 20

10

1

15 16

1 2
3 4
5 6

No.13

EN(H4DOSTC)-195

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

No

1

CHECK POWER SUPPLY CIRCUIT TO FUEL 
PUMP CONTROLLER.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from fuel pump 

controller.

3) Turn the ignition switch to ON.
4) Measure the voltage between fuel pump 

controller and chassis ground.

Connector & terminal

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

Does the measured value exceed the spec-
ified value?

10 V

Go to step 2.

Repair the power 
supply circuit.

NOTE:
In this case repair
the following:
• Open or ground 
short circuit in har-
ness between fuel 
pump relay and 
fuel pump control-
ler.
• Poor contact in 
fuel pump control-
ler connector.
• Poor contact in 
fuel pump relay 
connector.

2

CHECK GROUND CIRCUIT OF FUEL PUMP 
CONTROLLER.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness 

between fuel pump controller and chassis 
ground.

Connector & terminal

(R122) No. 5 — Chassis ground:

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

5 

Ω

Go to step 3.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following:
• Open circuit 
between fuel 
pump controller 
and chassis 
ground.
• Poor contact in 
fuel pump control-
ler connector.

3

CHECK HARNESS BETWEEN FUEL PUMP 
CONTROLLER AND FUEL PUMP CONNEC-
TOR.
1) Disconnect the connector from fuel pump.
2) Measure the resistance of harness 

between fuel pump controller and fuel 
pump connector.

Connector & terminal

(R122) No. 7 — (R58) No. 2:
(R122) No. 6 — (R58) No. 1:

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

1 

Ω

Go to step 4.

Repair the open 
circuit between 
fuel pump control-
ler and fuel pump.

4

CHECK HARNESS BETWEEN FUEL PUMP 
CONTROLLER AND FUEL PUMP CONNEC-
TOR.
Measure the resistance of harness between 
fuel pump controller and chassis ground.

Connector & terminal

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

Does the measured value exceed the specified 
value?

1 M

Ω

Go to step 5.

Repair the ground 
short circuit 
between fuel 
pump controller 
and fuel pump.

EN(H4DOSTC)-196

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

5

CHECK HARNESS BETWEEN FUEL PUMP 
CONTROLLER AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance of harness 

between fuel pump controller and ECM 
connector.

Connector & terminal

(R122) No. 9 — (B134) No. 13:
(R122) No. 8 — (B136) No. 16:

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

1 

Ω

Go to step 6.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following:
• Open circuit 
between fuel 
pump controller 
and ECM.
• Poor contact in 
fuel pump control-
ler and ECM con-
nector.

6

CHECK HARNESS BETWEEN FUEL PUMP 
CONTROLLER AND ECM CONNECTOR.
Measure the resistance of harness between 
fuel pump controller and chassis ground.

Connector & terminal

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

Does the measured value exceed the specified 
value?

1 M

Ω

Go to step 7.

Repair the ground 
short circuit 
between fuel 
pump controller 
and ECM.

7

CHECK POOR CONTACT.
Check poor contact in ECM and fuel pump 
controller connector.
Is there poor contact in ECM and fuel pump 
controller connector.

There is poor contact.

Repair the poor 
contact in ECM 
and fuel pump 
controller.

Replace the fuel 
pump controller. 
<Ref. to 
FU(H4DOSTC)-
43, Fuel Pump 
Controller.>

Step

Value

Yes

No

EN(H4DOSTC)-197

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

MEMO: