Subaru Legacy IV (2008 year). Service manual - part 1182

LAN(diag)-62

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

3

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

Is the DTC displayed a current 
malfunction?

Go to step 5.

Go to step 4.

4

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 5.

5

CHECK HARNESS.
1) Disconnect the body integrated unit connec-
tor (B280).
2) Measure the resistance between harness 
connectors.

Connector & terminal

(B280) No. 20 — No. 30:

Is the resistance 55 — 65 

:?

(Specification 60 

:)

Go to step 8.

Go to step 6.

6

CHECK HARNESS.
1) Disconnect the body integrated unit connec-
tor (B280).
2) Measure the resistance between harness 
connectors.

Connector & terminal

(B280) No. 20 — No. 30:

Is the resistance 115 — 125 

:?

(End resistance or main wiring 
harness is open.)

Go to step 7.

If the resistance is 
1 M 

: or larger, a 

line related to the 
body integrated 
unit is open. Repair 
the open circuit of 
harness or replace 
harness.

7

CHECK ECM.
Read the DTC of ECM using the Subaru Select 
Monitor. <Ref. to EN(H6DO)(diag)-43, SUB-
ARU SELECT MONITOR (NORMAL MODE), 
OPERATION, Read Diagnostic Trouble Code 
(DTC).>

Are there any DTCs other than 
one for “CAN communication”?

Perform the diag-
nosis according to 
DTC. <Ref. to 
EN(H6DO)(diag)-
43, SUBARU 
SELECT MONI-
TOR (NORMAL 
MODE), OPERA-
TION, Read Diag-
nostic Trouble 
Code (DTC).>

Go to step 8.

8

CHECK BODY INTEGRATED UNIT.
1) Connect all the control module connectors.
2) Check the data of “body integrated unit data 
received” on the current data display of ECM 
using Subaru Select Monitor.

Is the “ON” displayed?

Go to step 9.

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

9

CHECK BODY INTEGRATED UNIT.
Check the data of “body integrated unit counter 
update” on the data display of ECM.

Is the “ON” displayed?

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

Inspect the ECM. 
<Ref. to 
FU(H4SO)-39,
REMOVAL, Engine 
Control Module 
(ECM).> <Ref. to 
FU(H4DOTC)-52, 
REMOVAL, Engine 
Control Module 
(ECM).> <Ref. to 
FU(H6DO)-38, 
REMOVAL, Engine 
Control Module 
(ECM).>

Step

Check

Yes

No

LAN(diag)-63

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

N: DTC U1222 CAN-HS TCM NO-RECEIVE DATA

DTC DETECTING CONDITION:
TCM has error, harness between the main harness splice and TCM is open or shorted, connectors are not
connected securely, or the terminal has poor crimping.
TROUBLE SYMPTOM:
• Malfunction indicator light illuminates.
• “Er HC” is displayed in odo/trip meter. (Except for meter with MID)
WIRING DIAGRAM:

LAN00382

B40

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16

B280

B:

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

B231

1 2 3 4

A: B54

16

10 11 12 13 14 15

25

24

30

9

8

7

17 18 19 20
28

21 22 23

29

32

31

1

2

3

4

5

6

27

26

33 34 35

B310

4 5 6 7 8 9

26 27 28 29 30

2 3

1

31 32 33 34 35 36

10 11

14 15 16 17 18 19

37 38 39 40

12 13

41 42 43 44 45 46

20 21

23

24

22

25

B230

1

2

3

4

B170

3 4

5 6

1 2

7 8

1 2 3 4 5 6 7 8 9 10

11 12 13 14 15 16 17 18 19 20

B365

B301

4 5 6 7 8 9

16 17 18 19 20

2 3

1

21 22 23 24 25 26

10 11

13

14

12

15

C: B136

B:

B55

5

6

7

2

1

3

4

29

10 11 12 13 14 15

25

24

16

30

9

8

17 18 19

20
28

21 22 23

32

31

26 27

33

34 35

2

3

B230

YAW RATE 

SENSOR

B231

2

1

STEERING

ANGLE

SENSOR

VDCCM & H/U

B310

35

10

ECM

B136

27

35

B30

B20

BODY 

INTEGRATED UNIT

B280

B:

6

14

B170

B365

B40

CAN JOINT 
CONNEC-
TOR

CAN JOINT 
CONNECTOR

DATA LINK 

CONNECTOR

2

*

1

*

2

*

1

*

3

*

4

*

2

*

1

*

2

*

1

*

2

*

1

*

2

*

1

*

3

*

4

*

3

*

4

*

VDC

VDC

VDC

VDC

ABS

ABS

ABS

ABS

ABSCM & H/U

B301

26

11

VDC

ABS

ABS

TCM

B54

A:

4AT MODEL

5AT MODEL

B21

B20

A18

A17

B55

B:

VDC

*

1

*

2

*

3

*

4

: WITHOUT VDC

ABS

VDC

: TERMINAL No. OPTIONAL ARRANGEMENT 
  AMONG 1, 2, 3, 11, 12 AND 13
: TERMINAL No. OPTIONAL ARRANGEMENT 
  AMONG 8, 9, 10, 18, 19 AND 20
: TERMINAL No. OPTIONAL ARRANGEMENT 
  AMONG 1, 2, 5 AND 6
: TERMINAL No. OPTIONAL ARRANGEMENT 
  AMONG 3, 4, 7 AND 8

: WITH VDC

LAN(diag)-64

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK DTC.
Connect the Subaru Select Monitor and read all 
DTCs.

Is there any DTC other than for 
the body integrated unit?

Perform the diag-
nosis according to 
the DTC of other 
control modules.

Go to step 2.

2

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

Is the DTC displayed a 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 the DTC displayed a current 
malfunction?

Go to step 5.

Go to step 4.

4

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 5.

5

CHECK HARNESS.
1) Disconnect the TCM connector (B54 or 
B55).
2) Measure the resistance between harness 
connector terminals.

Connector & terminal

4AT model:

(B54) No. 17 — No. 18:

5AT model:

(B55) No. 20 — No. 21:

Is the resistance 1 M

: or 

more?

Open circuit in 
related lines of 
TCM. Repair the 
open circuit of har-
ness or replace 
harness.

Go to step 6.

6

CHECK TCM.
Read the DTC of the TCM using Subaru Select 
Monitor. <Ref. to 5AT(diag)-18, OPERATION, 
Subaru Select Monitor.>

Is DTC other than “CAN com-
munication” displayed?

Perform the diag-
nosis according to 
DTC.

Go to step 7.

7

CHECK BODY INTEGRATED UNIT.
1) Connect all the control module connectors.
2) Check the data of “body integrated unit data 
received” on the current data display of ECM 
using Subaru Select Monitor.

Is the “ON” displayed?

Go to step 8.

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

8

CHECK BODY INTEGRATED UNIT.
Check the data of “body integrated unit counter 
update” on the data display of ECM.

Is the “ON” displayed?

Replace the TCM. 
<Ref. to 4AT-61, 
REMOVAL, Trans-
mission Control 
Module (TCM).> 
<Ref. to 5AT-60, 
REMOVAL, Trans-
mission Control 
Module (TCM).>

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

LAN(diag)-65

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

O: DTC U1223 CAN-HS VDC/ABS NO-RECEIVE DATA

DTC DETECTING CONDITION:
Defective VDC/ABSCM. (If error is in the main harness, DTC P0600 High-speed CAN circuit is input at the
same time.
TROUBLE SYMPTOM:
• ABS warning light and VDC warning light come on.
• “Er HC” is displayed in odo/trip meter. (Except for meter with MID)
WIRING DIAGRAM:

LAN00382

B40

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16

B280

B:

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

B231

1 2 3 4

A: B54

16

10 11 12 13 14 15

25

24

30

9

8

7

17 18 19 20
28

21 22 23

29

32

31

1

2

3

4

5

6

27

26

33 34 35

B310

4 5 6 7 8 9

26 27 28 29 30

2 3

1

31 32 33 34 35 36

10 11

14 15 16 17 18 19

37 38 39 40

12 13

41 42 43 44 45 46

20 21

23

24

22

25

B230

1

2

3

4

B170

3 4

5 6

1 2

7 8

1 2 3 4 5 6 7 8 9 10

11 12 13 14 15 16 17 18 19 20

B365

B301

4 5 6 7 8 9

16 17 18 19 20

2 3

1

21 22 23 24 25 26

10 11

13

14

12

15

C: B136

B:

B55

5

6

7

2

1

3

4

29

10 11 12 13 14 15

25

24

16

30

9

8

17 18 19

20
28

21 22 23

32

31

26 27

33

34 35

2

3

B230

YAW RATE 

SENSOR

B231

2

1

STEERING

ANGLE

SENSOR

VDCCM & H/U

B310

35

10

ECM

B136

27

35

B30

B20

BODY 

INTEGRATED UNIT

B280

B:

6

14

B170

B365

B40

CAN JOINT 
CONNEC-
TOR

CAN JOINT 
CONNECTOR

DATA LINK 

CONNECTOR

2

*

1

*

2

*

1

*

3

*

4

*

2

*

1

*

2

*

1

*

2

*

1

*

2

*

1

*

3

*

4

*

3

*

4

*

VDC

VDC

VDC

VDC

ABS

ABS

ABS

ABS

ABSCM & H/U

B301

26

11

VDC

ABS

ABS

TCM

B54

A:

4AT MODEL

5AT MODEL

B21

B20

A18

A17

B55

B:

VDC

*

1

*

2

*

3

*

4

: WITHOUT VDC

ABS

VDC

: TERMINAL No. OPTIONAL ARRANGEMENT 
  AMONG 1, 2, 3, 11, 12 AND 13
: TERMINAL No. OPTIONAL ARRANGEMENT 
  AMONG 8, 9, 10, 18, 19 AND 20
: TERMINAL No. OPTIONAL ARRANGEMENT 
  AMONG 1, 2, 5 AND 6
: TERMINAL No. OPTIONAL ARRANGEMENT 
  AMONG 3, 4, 7 AND 8

: WITH VDC