Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 787

LAN(diag)-57

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

K: DTC U1221 CAN-HS ECM NO-RECEIVE DATA

DTC DETECTING CONDITION:

Not received data from ECM.

TROUBLE SYMPTOM:

Malfunction indicator light illuminates.

WIRING DIAGRAM:

CAN communication system <Ref. to WI-171, WIRING DIAGRAM, CAN Communication System.>

Step

Check

Yes

No

1

CHECK DTC.
Read all DTCs using the Subaru Select Monitor.
<Ref. to LAN(diag)-13, READ DIAGNOSTIC
TROUBLE CODE (DTC), OPERATION, Subaru
Select Monitor.>

Is there DTC U1202?

Perform the diag-
nosis according to
DTC.

Go to step

2.

2

CHECK DTC.
Read the DTC of body integrated unit using
Subaru Select Monitor.

Is U1221 a current malfunc-
tion?

Go to step

3.

Go to step

8.

2

1

B231

1

8

2

B380

B3

B9

B280

B:

6

14

B40

B380

1 2 3 4

17 18 19 20

5 6 7 8

21 22 23 24

9 10 11 12

25 26 27 28

13 14 15 16
29 30 31 32

4 5 6 7 8 9

6

2

7

2

8

2

9

2

0

3

2 3

1

1

3

2

3

3

3

4

3

5

3

6

3

0

1

1

1

4

1

5

1

6

1

7

1

8

1

9

1

7

3

8

3

9

3

0

4

2

1

3

1

1

4

2

4

3

4

4

4

5

4

6

4

0

2

1

2

3

2

4

2

2

2

5

2

B310

B231

1 2 3 4

B230

1

2

3

4

C: B136

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

B280

B:

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

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16

B40

C17

C28

C: B136

B230

3

2

B310

10

35

LAN00907

SI

SI

SI

VDC CM

ECM

DCCD CM

YAW RATE &

G SENSOR

: WITH SI-DRIVE

DATA LINK

CONNECTOR

BODY

INTEGRATED

UNIT

STEERING

ANGLE

SENSOR

LAN(diag)-58

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

3

CHECK DTC.
1) Turn the ignition switch to OFF.
2) Disconnect all control module connectors
(B280, B310, B136, B230, B231, B380) that are
connected to high speed CAN communication
line.
3) Connect the disconnected connectors.
4) Turn the ignition switch to ON.
5) Read the DTC of body integrated unit using
Subaru Select Monitor.

Is U1221 a current malfunc-
tion?

Go to step

4.

Go to step

8.

4

CHECK HARNESS.
1) Turn the ignition switch to OFF.
2) Disconnect all control module connectors
(B280, B310, B136, B230, B231, B380) that are
connected to high speed CAN communication
line.
3) Using the tester, check for open, short
(power supply-output short, GND-output short)
in the harness.

Connector & terminal

(B40) No. 6 — (B136) No. 17:
(B40) No. 6 — (B310) No. 35:
(B40) No. 6 — (B230) No. 2:
(B40) No. 6 — (B231) No. 2:
(B40) No. 6 — (B380) No. 2 (with SI-
DRIVE):
(B40) No. 6 — (B280) No. 3:

Is harness normal?

Go to step

5.

Repair or replace
the harness.

5

CHECK HARNESS.
Using the tester, check for open, short (power
supply-output short, GND-output short) in the
harness.

Connector & terminal

(B40) No. 14 — (B136) No. 28:
(B40) No. 14 — (B310) No. 10:
(B40) No. 14 — (B230) No. 3:
(B40) No. 14 — (B231) No. 1:
(B40) No. 14 — (B380) No. 18 (with SI-
DRIVE):
(B40) No. 14 — (B280) No. 9:

Is harness normal?

Go to step

6.

Repair or replace
the harness.

6

CHECK DTC.
1) Turn the ignition switch to OFF.
2) Connect the disconnected connectors.
3) Start the engine and stop.
4) Turn the ignition switch to ON.
5) Read the DTC of body integrated unit using
Subaru Select Monitor.

Is U1221 a current malfunc-
tion?

Go to step

7.

Go to step

8.

7

CHECK DTC.
Read all DTCs using the Subaru Select Monitor.

Is DTC C0047 detected?

Replace the ECM.
<Ref. to FU(STI)-
59, REMOVAL,
Engine Control
Module (ECM).>
<Ref. to FU(w/o
STI)-57,
REMOVAL, Engine
Control Module
(ECM).>

Replace the body
integrated unit.
<Ref. to SL-48,
REMOVAL, Body
Integrated Unit.>

Step

Check

Yes

No

LAN(diag)-59

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

8

CHECK HARNESS.
1) Turn the ignition switch to OFF.
2) Shake the harness used for CAN communi-
cation circuit.
3) Turn the ignition switch to ON.
4) Read the DTC of body integrated unit using
Subaru Select Monitor.

Is U1221 a current malfunc-
tion?

Repair or replace
the harness.

Go to step

9.

9

CHECK CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect all the connector that is con-
nected to high speed CAN circuit.

Is there poor contact of connec-
tor terminal?

Repair the connec-
tor terminal where
poor contact
exists, or replace
harness.

Temporary com-
munication failure
occurs.

Step

Check

Yes

No

LAN(diag)-60

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

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

DTC DETECTING CONDITION:

Not received data from VDC/ABS CM.

TROUBLE SYMPTOM:

ABS warning light and VDC warning light illuminate.

WIRING DIAGRAM:

CAN communication system <Ref. to WI-171, WIRING DIAGRAM, CAN Communication System.>

Step

Check

Yes

No

1

CHECK DTC.
Read all DTCs using the Subaru Select Monitor.
<Ref. to LAN(diag)-13, READ DIAGNOSTIC
TROUBLE CODE (DTC), OPERATION, Subaru
Select Monitor.>

Is there DTC U1202?

Perform the diag-
nosis according to
DTC.

Go to step

2.

2

CHECK DTC.
Read the DTC of body integrated unit using
Subaru Select Monitor.

Is U1223 a current malfunc-
tion?

Go to step

3.

Go to step

7.

2

1

B231

1

8

2

B380

B3

B9

B280

B:

6

14

B40

B380

1 2 3 4

17 18 19 20

5 6 7 8

21 22 23 24

9 10 11 12

25 26 27 28

13 14 15 16
29 30 31 32

4 5 6 7 8 9

6

2

7

2

8

2

9

2

0

3

2 3

1

1

3

2

3

3

3

4

3

5

3

6

3

0

1

1

1

4

1

5

1

6

1

7

1

8

1

9

1

7

3

8

3

9

3

0

4

2

1

3

1

1

4

2

4

3

4

4

4

5

4

6

4

0

2

1

2

3

2

4

2

2

2

5

2

B310

B231

1 2 3 4

B230

1

2

3

4

C: B136

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

B280

B:

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

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16

B40

C17

C28

C: B136

B230

3

2

B310

10

35

LAN00907

SI

SI

SI

VDC CM

ECM

DCCD CM

YAW RATE &

G SENSOR

: WITH SI-DRIVE

DATA LINK

CONNECTOR

BODY

INTEGRATED

UNIT

STEERING

ANGLE

SENSOR