Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 779

LAN(diag)-25

Subaru Select Monitor

LAN SYSTEM (DIAGNOSTICS)

B: INSPECTION

1. COMMUNICATION FOR INITIALIZING IMPOSSIBLE

DETECTING CONDITION:

Defective harness connector

TROUBLE SYMPTOM:

Not communicable with Subaru Select Monitor.

WIRING DIAGRAM:

• SECURITY SYSTEM <Ref. to WI-154, WIRING DIAGRAM, Security System.>

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

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 3 4 5

1

6 7 8

i97

*

1

i97

*

1

*

1

B225

13
14

15 16

17

27

24

25
26

20

21
22

23

29
30

31

28

32 35

33
34

37
38

39

36

40

8

9

10

11 12

1

2

5

3

4

7

6

19

18

3

4

10A

B225

i84

A:

B20

B6

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

A2

8

C2

B280

B:

6

4 5

3

1 2

9

7 8

17

6

1

5

1

4

1

3

1

2

1

1

1

0

1

20

9

1

8

1

24

3

2

2

2

1

2

26

5

2

4

5

7

8

6

1

B40

D27

B17

C20

B40

1 2 3 4 5 6 7 8
9 0

1

1

1

2

1

3

1

4

1

5

1

6

1

5

7

6

4

8

2

1

9

3

0

1

3

2

2

2

1

1

2

1

3

1

4

1

5

1

7

2

6

2

5

2

4

2

6

1

7

1

8

1

9

2

8

2

9

1

0

2

21

30

B279

D:

7

5 6

8

2

1

9

4

3

0

1

4

2

5

2

3

2

2

2

1

1

2

1

3

1

4

1

5

1

8

2

7

2

6

2

6

1

7

1

8

1

9

1

1

2

0

2

B281

C:

D: B279

B: B280 C: B281

LAN00603

MB-27

M/B FUSE NO. 13

(B)

FB-32

F/B FUSE NO. 4

(IG)

MB-29

M/B FUSE NO. 8

(B)

TO POWER SUPPLY CIRCUIT

BODY INTEGRATED UNIT

DATA LINK

CONNECTOR

REF. TO ENGINE

ELECTRICAL

SYSTEM

FB-18

F/B FUSE NO. 7

(B)

FUSE (RELA

Y BLOCK)

RELAY BLOCK

JOINT GROUND

CONNECTOR

: TERMINAL No. OPTIONAL

ARRANGEMENT

LAN(diag)-26

Subaru Select Monitor

LAN SYSTEM (DIAGNOSTICS)

2

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

Is the voltage 11 V or more?

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.

Is the system name 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 unit connec-
tor.
3) Turn the ignition switch to ON.
4) Check whether communication to other sys-
tems can be executed normally.

Is the system name displayed? Go to step

7.

Go to step

6.

6

CHECK HARNESS CONNECTOR BETWEEN
EACH CONTROL MODULE AND SUBARU
SELECT MONITOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between data link
connector and chassis ground.

Connector & terminal

(B40) No. 7 — Chassis ground:

Is the resistance 1 MΩ or
more?

Go to step

7.

Repair the harness
and connector
between each con-
trol module and
Subaru Select
Monitor.

7

CHECK OUTPUT SIGNAL TO BODY INTE-
GRATED UNIT.
1) Turn the ignition switch to ON.
2) Measure the voltage between data link con-
nector and chassis ground.

Connector & terminal

(B40) No. 7 (+) — Chassis ground (–):

Is the voltage less than 1 V?

Go to step

8.

Repair the harness
and connector
between each con-
trol module and
Subaru Select
Monitor.

8

CHECK HARNESS CONNECTOR BETWEEN
BODY INTEGRATED UNIT AND DATA LINK
CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between body inte-
grated unit and data link connector.

Connector & terminal

(B40) No. 7 — (B280) No. 20:

Is the resistance less than 1 Ω? Go to step

9.

Repair the harness
and connector
between body inte-
grated unit and
Subaru Select
Monitor.

9

CHECK BACK-UP FUSE.
Check that back-up fuse is not blown out, or
check that it is inserted.

Is back-up fuse OK?

Go to step

10.

Replace the back-
up fuse, or insert it
into the fuse
holder.

10

CHECK POWER SUPPLY CIRCUIT.
1) Connect the body integrated unit.
2) Measure the voltage between body inte-
grated unit connector and chassis ground.

Connector & terminal

(B280) No. 6 (+) — Chassis ground (–):
(B281) No. 2 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Go to step

11.

Repair the open
circuit of harness
between body inte-
grated unit and
battery.

Step

Check

Yes

No

LAN(diag)-27

Subaru Select Monitor

LAN SYSTEM (DIAGNOSTICS)

CAUTION:

For model with immobilizer, immobilizer registration work is necessary when the body integrated

unit replaced. For operation procedures, refer to “REGISTRATION MANUAL FOR IMMOBILIZER”.

11

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

Connector & terminal

(i84) No. 28 — Chassis ground:
(B279) No. 27 — Chassis ground:
(B280) No. 17 — Chassis ground:
(B281) No. 20 — Chassis ground:

Is the resistance 1 MΩ or
more?

Go to step

12.

Repair the poor
contact of harness
between body inte-
grated unit and
ground.

12

CHECK POOR CONTACT OF CONNECTOR. Is there poor contact of the con-

trol unit ground and the Subaru
Select Monitor?

Repair the poor
contact of connec-
tor.

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

Step

Check

Yes

No

LAN(diag)-28

Read Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

7. Read Diagnostic Trouble

Code (DTC)

A: OPERATION

For details concerning DTC reading procedure, re-

fer to “Subaru Select Monitor”. <Ref. to LAN(diag)-

13, READ DIAGNOSTIC TROUBLE CODE (DTC),

OPERATION, Subaru Select Monitor.>