Subaru Legacy IV (2008 year). Manual - part 1184

LAN(diag)-70

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

Q: DTC U1301 CAN-LS COUNTER ABNORMAL

DTC DETECTING CONDITION:
Find the unit in which trouble occurs and open or short CAN line, and repair and replace them.
(Free running counter error may be detected at the same time from the unit in which the malfunction occurs.)
TROUBLE SYMPTOM:
“Er LC” is displayed in odo/trip meter. (Except for meter with MID)
WIRING DIAGRAM:

i106

i10

B282

21

22

14

6

i119

A27

A26

B26

B25

i84

B280

10

9

B:

A:

B:

i107

*

1

*

1

*

1

*

1

*

1

*

1

i10

LAN00383

CAN
JOINT
CONNECTOR

ON

WN

WN

ON

TWISTED PAIR LINE

TWISTED PAIR LINE

COMBINATION METER

BODY 

INTEGRATED 

UNIT

i119

1 2 3 4 5 6 7 8
9 10 11 12 13 14 15 16

1 2 3 4 5

6 7 8 9 10

11 12

19 20 21

13 14 15 16 17 18

22

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

B280

A:

i84

1 2

3 4

5 6

7 8

9 10 11 12

14 15 16 17 18 19 20 21 22 23

24 25

26 27 28 29

30 31 32 33

34 35

13

B282

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 36 37 38 39 40

*

1

ON

WN

WA

WA

WA

AUTO A/C

CONTROL 

MODULE

CENTER

DISPLAY

: TERMINAL No. OPTIONAL ARRANGEMENT

: WITH NAVIGATION

: WITHOUT NAVIGATION 

: WITH AUTO A/C

LAN(diag)-71

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK DTC.
Connect the Subaru Select Monitor and read 
the DTC of the body integrated unit.

Are there any other DTC 
besides U1301?

Perform diagnosis 
according to other 
DTC.

Go to step 2.

2

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

Is U1301 current malfunction?

Check the connec-
tion of harness 
connectors. Go to 
step 3.

Go to step 3.

3

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

Is U1301 current malfunction?

Go to step 4.

Temporary poor 
contact occurs.

4

CHECK CURRENT DATA.
Check the current data (auto A/C failure) of the 
body integrated unit using the Subaru Select 
Monitor.

Is OK displayed?

Go to step 5.

Perform the auto A/
C self-diagnosis. 
<Ref. to AC(diag)-
9, OPERATION, 
Diagnostic Chart 
for Self-Diagno-
sis.>

5

CHECK AUTO A/C ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the auto A/C control module 
connector (B282).
3) Connect the Subaru Select Monitor and 
then turn the ignition switch to ON.
4) Perform the clear memory operation for the 
body integrated unit.
5) Read the DTC of the body integrated unit.

Is DTC U1301 detected?

Go to step 7.

Go to step 6.

6

CHECK HARNESS.
1) Disconnect the body integrated unit connec-
tor (B280) and auto A/C control module connec-
tor (B282).
2) Check open or short conditions between 
body integrated unit connector and auto A/C 
control module connector.

Connector & terminal

(B282) No. 10 — (B280) No. 26:
(B282) No. 9 — (B280) No. 25:

Is harness normal?

Replace auto A/C 
ECM. <Ref. to AC-
35, REMOVAL, 
Control Unit (Auto 
A/C Model).>

Repair or replace 
the open or short 
circuit of harness.

7

CHECK CURRENT DATA.
Check current data (center display failure) of the 
body integrated unit.

Is OK displayed?

Go to step 8.

Repair or replace 
the center display. 
<Ref. to ET-19, 
REMOVAL, Navi-
gation Display.>

8

CHECK CENTER DISPLAY.
1) Turn the ignition switch to OFF.
2) Disconnect the center display connector 
(i119).
3) Connect the Subaru Select Monitor and 
then turn the ignition switch to ON.
4) Perform the clear memory operation for the 
body integrated unit.
5) Read the DTC of the body integrated unit.

Is DTC U1301 detected?

Go to step 10.

Go to step 9.

9

CHECK HARNESS.
1) Disconnect the body integrated unit connec-
tor (B280) and center display connector (i119).
2) Check open or short conditions between 
body integrated unit connector and center dis-
play connector.

Connector & terminal

(i119) No. 14 — (i84) No. 26:
(i119) No. 6 — (i84) No. 27:

Is harness normal?

Replace the center 
display. <Ref. to 
AC-35, REMOVAL, 
Control Unit (Auto 
A/C Model).>

Repair or replace 
the open or short 
circuit of harness.

LAN(diag)-72

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

10

CHECK CURRENT DATA.
Check current data (meter failure) of the body 
integrated unit.

Is OK displayed?

Go to step 11.

Replace the com-
bination meter. 
<Ref. to IDI-22, 
REMOVAL, Com-
bination Meter.>

11

CHECK COMBINATION METER.
1) Turn the ignition switch to OFF.
2) Disconnect the combination meter connec-
tor (i10).
3) Connect the Subaru Select Monitor and 
then turn the ignition switch to ON.
4) Perform the clear memory operation for the 
body integrated unit.
5) Read the DTC of the body integrated unit.

Is DTC U1301 detected?

Go to step 13.

Go to step 12.

12

CHECK HARNESS.
1) Disconnect the combination meter connec-
tor (i10).
2) Check open or short conditions between 
body integrated unit connector and combination 
meter connector.

Connector & terminal

(i10) No. 21 — (i84) No. 27:
(i10) No. 22 — (i84) No. 26:

Is harness normal?

Replace the com-
bination meter. 
<Ref. to IDI-22, 
REMOVAL, Com-
bination Meter.>

Repair or replace 
the open or short 
circuit of harness.

13

CHECK HARNESS.
1) Disconnect connectors of A/C ECM (B282), 
center monitor (i119), combination meter (i10) 
and body integrated unit connector (i84).
2) Measure the resistance between connector 
terminals.

Connector & terminal

(i84) No. 27 — (i84) No. 26:

Is the resistance 1 M

: or 

more?

Go to step 14.

Repair the short 
circuit of harness 
or replace har-
ness.

14

CHECK HARNESS.
1) Connect the disconnected connectors.
2) Measure the resistance between body inte-
grated unit connector and chassis ground.

Connector & terminal

(B280) No. 25 — Chassis ground:
(B280) No. 26 — Chassis ground:
(i84) No. 26 — Chassis ground:
(i84) No. 27 — Chassis ground:

Is the resistance less than 10 

:? Repair the short 

circuit of harness 
or replace har-
ness.

Go to step 15.

15

CHECK HARNESS.
1) Turn the ignition switch to ON.
2) Measure the voltage between body inte-
grated unit connector and chassis ground.

Connector & terminal

(B280) No. 25 (+) — Chassis ground (–):
(B280) No. 26 (+) — Chassis ground (–):
(i84) No. 26 (+) — Chassis ground (–):
(i84) No. 27 (+) — Chassis ground (–):

Is the voltage 6 V or more?

Repair the short 
circuit of harness 
or replace har-
ness.

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

Step

Check

Yes

No

LAN(diag)-73

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

R: DTC U1302 CAN-LS BUS OFF

DTC DETECTING CONDITION:
• Because of a lot of error data occurred, some units have been disconnected not to affect other units.
• Communication failure from the unit in which error is occurred is input at the same time.
TROUBLE SYMPTOM:
“Er LC” is displayed in odo/trip meter. (Except for meter with MID)
WIRING DIAGRAM:

i106

i10

B282

21

22

14

6

i119

A27

A26

B26

B25

i84

B280

10

9

B:

A:

B:

i107

*

1

*

1

*

1

*

1

*

1

*

1

i10

LAN00383

CAN
JOINT
CONNECTOR

ON

WN

WN

ON

TWISTED PAIR LINE

TWISTED PAIR LINE

COMBINATION METER

BODY 

INTEGRATED 

UNIT

i119

1 2 3 4 5 6 7 8
9 10 11 12 13 14 15 16

1 2 3 4 5

6 7 8 9 10

11 12

19 20 21

13 14 15 16 17 18

22

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

B280

A:

i84

1 2

3 4

5 6

7 8

9 10 11 12

14 15 16 17 18 19 20 21 22 23

24 25

26 27 28 29

30 31 32 33

34 35

13

B282

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 36 37 38 39 40

*

1

ON

WN

WA

WA

WA

AUTO A/C

CONTROL 

MODULE

CENTER

DISPLAY

: TERMINAL No. OPTIONAL ARRANGEMENT

: WITH NAVIGATION

: WITHOUT NAVIGATION 

: WITH AUTO A/C