Subaru Legacy IV (2008 year). Manual - part 1176

LAN(diag)-38

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK FUSE.
1) Turn the ignition switch to OFF.
2) Remove the fuse (No. 8).

Is the fuse blown out?

Replace the fuse 
(No. 8). If the 
replaced fuse has 
blown out easily, 
repair the short cir-
cuit of harness 
between fuse (No. 
8) and body inte-
grated unit.

Go to step 2.

2

CONTINUITY CHECK OF WIRING HAR-
NESS.
1) Disconnect the connector (B280) from body 
integrated unit.
2) Measure the voltage between body inte-
grated unit connector and chassis ground.

Connector & terminal

(B280) No. 7 (+) — Chassis ground (–):

Is the voltage 9 — 15 V?

Go to step 3.

Repair the harness 
for open or shorted 
circuit between 
body integrated 
unit and fuse.

3

CHECK POOR CONTACT OF CONNEC-
TORS.

Is there poor contact in body 
integrated unit connector?

Repair the poor 
contact of connec-
tor.

Go to step 4.

4

CHECK BODY INTEGRATED UNIT HAR-
NESS.
1) Connect all connectors.
2) Perform the Clear Memory Mode.
3) Read DTC.

Is the same DTC displayed?

Replace the body 
integrated unit. 
<Ref. to SL-56, 
Body Integrated 
Unit.>

Temporary poor 
contact occurs.

LAN(diag)-39

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

D: DTC B1103 IGNITION POWER FAILURE

DTC DETECTING CONDITION:
IGN power supply circuit is open or shorted.
TROUBLE SYMPTOM:
Symptoms such as illuminating the malfunction indicator light or high speed CAN error display “Er HC” may
occur. (Except for meter with MID)
WIRING DIAGRAM:

LAN00381

BODY INTEGRATED UNIT

A1

A24

MICRO COMPUTER

A1

A8

B72

IGNITION SWITCH

1

B

2

4

ACC

ACC

OFF

IG

ON

B280

B:

B281

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

5

4

6 7

8

2

1

9

3

10

22

23

11 12 13 14 15

24 25

26 27

16 17 18

28 29

19 20

21

30

i84

A:

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 31 32 33

34 35

A

CC PO

WER SUPPL

Y

i5

A:

E

MAIN SBF-11

FB-28 No.

 31

BATTERY

IG PO

WER SUPPL

Y

i84

B280

B:

A:

B281

C:

A21

C9

B22

C8

E

E

FB-37 No.

 12

B72

1

3

4 5 6

2

i5

A:

1 2 3 4

10 11 12 13

5 6 7 8 9

19 20

14 15 16 17 18

LAN(diag)-40

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK FUSE.
1) Turn the ignition switch to OFF.
2) Remove the fuse (No. 12).

Is the fuse blown out?

Replace the fuse 
(No. 12). If the 
replaced fuse has 
blown out easily, 
repair the short cir-
cuit of harness 
between fuse (No. 
12) and body inte-
grated unit.

Go to step 2.

2

CONTINUITY CHECK OF WIRING HAR-
NESS.
1) Disconnect the connector (i84) from body 
integrated unit.
2) Turn the ignition switch to ON.
3) Measure the voltage between body inte-
grated unit connector and chassis ground.

Connector & terminal

(i84) No. 1 (+) — Chassis ground (–):

Is the voltage 9 — 15 V?

Go to step 3.

Repair the harness 
for open or shorted 
circuit between 
body integrated 
unit and fuse.

3

CHECK POOR CONTACT IN CONNECTOR.

Is there poor contact in body 
integrated unit connector?

Repair the poor 
contact of connec-
tor.

Go to step 4.

4

CHECK BODY INTEGRATED UNIT HAR-
NESS.
1) Connect all connectors.
2) Perform the Clear Memory Mode.
3) Read DTC.

Is the same DTC displayed?

Replace the body 
integrated unit. 
<Ref. to SL-56, 
Body Integrated 
Unit.>

Temporary poor 
contact occurs.

LAN(diag)-41

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

E: DTC B1104 ACC POWER FAILURE

DTC DETECTING CONDITION:
ACC power supply circuit is open or shorted.
TROUBLE SYMPTOM:
Rear wiper may not operate at ACC position.
WIRING DIAGRAM:

LAN00381

BODY INTEGRATED UNIT

A1

A24

MICRO COMPUTER

A1

A8

B72

IGNITION SWITCH

1

B

2

4

ACC

ACC

OFF

IG

ON

B280

B:

B281

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

5

4

6 7

8

2

1

9

3

10

22

23

11 12 13 14 15

24 25

26 27

16 17 18

28 29

19 20

21

30

i84

A:

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 31 32 33

34 35

A

CC PO

WER SUPPL

Y

i5

A:

E

MAIN SBF-11

FB-28 No.

 31

BATTERY

IG PO

WER SUPPL

Y

i84

B280

B:

A:

B281

C:

A21

C9

B22

C8

E

E

FB-37 No.

 12

B72

1

3

4 5 6

2

i5

A:

1 2 3 4

10 11 12 13

5 6 7 8 9

19 20

14 15 16 17 18