Subaru Legacy IV (2008 year). Manual - part 1175

LAN(diag)-34

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

12.Diagnostic Procedure with Diagnostic Trouble Code (DTC)

A: DTC B1100 INTEG. UNIT SYSTEM ERROR

DTC DETECTING CONDITION:
System error in body integrated unit
TROUBLE SYMPTOM:
• Check light comes on in the combination meter, and displays communication error display “Er IU”. (Except
for meter with MID)
• LAN communication immobilizer function may not be executed normally.

Step

Check

Yes

No

1

CHECK DTC.
Check the DTC displayed in the body integrated 
unit.

Is the DTC displayed a current 
malfunction?

Check the connec-
tion of body inte-
grated unit. Go to 
step 2.

Go to step 2.

2

CHECK DTC.
Turn the ignition switch to OFF and read DTCs 
again.

Is the DTC displayed a current 
malfunction?

Go to step 4.

Go to step 3.

3

CHECK CURRENT DATA.
Using the Subaru Select Monitor, display 
engine speed and vehicle speed signal from 
ECM, TCM, VDC/ABS and body integrated unit 
under the same conditions and compare data.

Do all data values match?

Temporary poor 
contact occurs. 
Perform the Clear 
Memory operation.

Go to step 4.

4

CHECK ALL DTCS.

Is DTC concerning ECM dis-
played?

Go to step 5.

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

5

CHECK DTC CONCERNING ECM.

Is output DTC on ECM con-
cerning CAN communication 
failure?

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

Perform the diag-
nosis according to 
DTC concerning 
ECM.

LAN(diag)-35

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

B: DTC B1101 BATT P/SUPPLY MALFUNCTION CONT

DTC DETECTING CONDITION:
Battery power supply control circuit is open or shorted.
TROUBLE SYMPTOM:
No malfunction occurs because the back-up power supply is activated.

NOTE:
When B1102 BATT p/supply (backup) malfunction is output at the same time, all the function of body inte-
grated unit may not operate.
WIRING DIAGRAM:

LAN00380

SYSTEM CONTR

OL

PO

WER SUPPL

Y

B

A

CK-UP PO

WER SUPPL

Y

BODY INTEGRATED UNIT

B7

C2

A21

C9

B22

C8

MICRO COMPUTER

C19

D9

i84

B144

B280

B52

C:

D:

B:

A:

B52

C:

3 4

1 2

8 9 10 11

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

5

6 7

E

MAIN SBF-11

BATTERY

B281

C:

E

E

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

FB-18 No.

 7

MB-29 No.

 8

B144

D:

1
5

7

6

2

8

3

4
9

LAN(diag)-36

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. 7).

Is the fuse blown out?

Replace the fuse 
(No. 7). If the 
replaced fuse has 
blown out easily, 
repair the short cir-
cuit of harness 
between fuse (No. 
7) and body inte-
grated unit.

Go to step 2.

2

CONTINUITY CHECK OF WIRING HAR-
NESS.
1) Disconnect the connector (B281) from body 
integrated unit.
2) Measure the voltage between body inte-
grated unit connector and chassis ground.

Connector & terminal

(B281) No. 2 (+) — 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)-37

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

C: DTC B1102 BATT P/SUPPLY MALFUNCTION BACKUP

DTC DETECTING CONDITION:
Battery power supply backup circuit is open or shorted.
TROUBLE SYMPTOM:
• Engine malfunction indicator light may illuminates.
• Keyless entry, room light and key illumination do not operate.
• “En IU” may display in combination meter. (Except for meter with MID)

NOTE:
When B1101 BATT p/supply (cont.) malfunction are output at the same time, all function of body integrated
unit may not operate.
WIRING DIAGRAM:

LAN00380

SYSTEM CONTR

OL

PO

WER SUPPL

Y

B

A

CK-UP PO

WER SUPPL

Y

BODY INTEGRATED UNIT

B7

C2

A21

C9

B22

C8

MICRO COMPUTER

C19

D9

i84

B144

B280

B52

C:

D:

B:

A:

B52

C:

3 4

1 2

8 9 10 11

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

5

6 7

E

MAIN SBF-11

BATTERY

B281

C:

E

E

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

FB-18 No.

 7

MB-29 No.

 8

B144

D:

1
5

7

6

2

8

3

4
9