Subaru Legacy (2005 year). Manual - part 1038

LAN(diag)-31

LAN SYSTEM (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK IGNITION SWITCH.

Is the ignition switch ON?

Go to step 2.

Turn the ignition 
switch to ON, and 
select Integ. unit 
mode using Sub-
aru Select Monitor.

2

CHECK BATTERY.
1) Turn the ignition switch to OFF.
2) Measure the battery voltage.

Is the voltage more than 11 V? Go to step 3.

Charge or replace 
the battery.

3

CHECK BATTERY TERMINAL.

Is there poor contact at battery 
terminal?

Repair or tighten 
the battery termi-
nal.

Go to step 4.

4

CHECK COMMUNICATION OF SUBARU SE-
LECT MONITOR.
1) Turn the ignition switch to ON.
2) Using the Subaru Select Monitor, check 
whether communication to other systems can 
be executed normally.

Are system and model year 
displayed?

Go to step 7.

Go to step 5.

5

CHECK COMMUNICATION OF SUBARU SE-
LECT MONITOR.
1) Turn the ignition switch to OFF.
2) Disconnect the body integrated module 
connector.
3) Turn the ignition switch to ON.
4) Check whether communication to other 
systems can be executed normally.

Are system and model year 
displayed?

Go to step 7.

Go to step 6.

6

CHECK HARNESS CONNECTOR BETWEEN 
EACH CONTROL UNIT AND SUBARU SE-
LECT MONITOR.
1) Turn the ignition switch to OFF.
2) Disconnect the body integrated module 
connector.
3) Measure the resistance between data link 
connector and chassis ground.

Connector & terminal

(B40) No. 10 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 7.

Repair the har-
ness and connec-
tor between each 
control unit and 
Subaru Select 
Monitor.

7

CHECK OUTPUT SIGNAL TO BODY INTE-
GRATED MODULE.
1) Turn the ignition switch to ON.
2) Measure the voltage between body inte-
grated module connector and chassis ground.

Connector & terminal

(B40) No. 10 (+) — Chassis ground (

−

):

Is the voltage less than 1 V?

Go to step 8.

Repair the har-
ness and connec-
tor between each 
control unit and 
Subaru Select 
Monitor.

8

CHECK HARNESS CONNECTOR BETWEEN 
BODY INTEGRATED MODULE AND DATA 
LINK CONNECTOR.
Measure the resistance between body inte-
grated module connector and data link connec-
tor.

Connector & terminal

(B40) No. 10 — (B280) No. 19:

Is the resistance less than 1 
Ω?

Go to step 9.

Repair the har-
ness and connec-
tor between body 
integrated module 
and Subaru Select 
Monitor.

9

CHECK INSTALLATION OF BODY INTE-
GRATED MODULE CONNECTOR.
Turn the ignition switch to OFF.

Is the body integrated module 
connector inserted into body 
integrated module until the 
clamp locks onto it?

Go to step 10.

Insert the body 
integrated module 
connector into 
body integrated 
module.

LAN(diag)-32

LAN SYSTEM (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

CAUTION:
When replacing body integrated module on the model with immobilizer system, refer to “IMMOBILIZ-
ER TEACHING OPERATION MANUAL”.

10

CHECK POWER SUPPLY CIRCUIT.
1) Turn the ignition switch to ON (engine 
OFF).
2) Measure the voltage between body inte-
grated module connector and chassis ground.

Connector & terminal

(i84) No. 1 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Go to step 11.

Repair the open 
circuit of harness 
between the body 
integrated module 
and battery.

11

CHECK HARNESS CONNECTOR BETWEEN 
BODY INTEGRATED MODULE AND CHAS-
SIS GROUND.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from body inte-
grated module.
3) Measure the harness resistance between 
the body integrated module and chassis 
ground.

Connector & terminal

(B280) No. 19 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 12.

Repair the poor 
contact of har-
ness between the 
body integrated 
module and 
ground.

12

CHECK POOR CONTACT IN CONNECTORS. Is there poor contact at control 

unit ground and Subaru Select 
Monitor?

Replace the body 
integrated mod-
ule. <Ref. to SL-
44, Body Inte-
grated Module.>

Repair the poor 
contact connector.

Step

Check

Yes

No

LAN(diag)-33

LAN SYSTEM (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

B: DIAGNOSTIC TROUBLE CODE (DTC) IS NOT STORED

DIAGNOSIS:
Defective combination meter
TROUBLE SYMPTOM:
• Communication error in odo/trip meter is not cleared.
• “No trouble code” is displayed on Subaru Select Monitor.

NOTE:
If DTC is not displayed on Subaru Select Monitor, LAN communication System should be OK.

C: DTC B0100 INTEG. UNIT SYSTEM ERROR

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

Step

Check

Yes

No

1

CHECK COMMUNICATION ERROR WITH 
COMBINATION METER.
Turn the ignition switch to ON.

Is communication error dis-
played?

Check the DTC.

Go to step 2.

2

CHECK COMBINATION METER.
Perform the self-diagnosis of combination 
meter.

Is combination meter OK?

Go to step 3.

Replace the com-
bination meter. 
<Ref. to IDI-15, 
Combination 
Meter.>

3

CHECK BODY INTEGRATED MODULE.
1) Display the current data of ECM using Sub-
aru Select Monitor.
2) Check data of “body integrated module 
data received”.

Is the “Yes” displayed?

Go to step 4.

Replace the body 
integrated mod-
ule. <Ref. to SL-
44, Body Inte-
grated Module.>

4

CHECK BODY INTEGRATED MODULE.
1) Display the current data of ECM using Sub-
aru Select Monitor.
2) Check data of “body integrated module 
counter update”.

Is the “Yes” displayed?

Repair the poor 
contact in connec-
tor.

Replace the body 
integrated mod-
ule. <Ref. to SL-
44, Body Inte-
grated Module.>

Step

Check

Yes

No

1

CHECK DTC.

Is DTC concerning ECM dis-
played?

Go to step 2.

Replace the body 
integrated mod-
ule. <Ref. to SL-
44, Body Inte-
grated Module.>

2

CHECK DTC CONCERNING ECM.

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

Replace the body 
integrated mod-
ule. <Ref. to SL-
44, Body Inte-
grated Module.>

Perform the diag-
nosis according to 
DTC concerning 
ECM.

LAN(diag)-34

LAN SYSTEM (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

D: DTC B0101 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 “B0102 BATT p/supply (backup) malfunction” are output at the same time, all the function of body in-
tegrated module may not operate.
WIRING DIAGRAM:

LAN00171

B7

C2

A21

C9

B22

C8

24

13

i84

B52

B280

R168

B:

A:

1 2 3 4

5 6 7 8 9

10 11 12

19 20

13 14 15 16 17 18

R168

B52

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

FB-18 No.7

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

BATTERY

BODY INTEGRATED 

MODULE

B

A

CK-UP

PO

WER SUPPL

Y

SYSTEM CONTR

OL

PO

WER SUPPL

Y

MB-29 No.8

MAIN FUSE BOX

FUSE & RELAY BOX