Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 789

LAN(diag)-65

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

2

CHECK DTC.
1) Disconnect all control module connectors
(i84, i10, i88, i85) that are connected to low
speed CAN communication line.
2) Connect the disconnected connectors.
3) Turn the ignition switch to ON.
4) Read the DTC of body integrated unit using
Subaru Select Monitor.

Is U1300 a current malfunc-
tion?

Go to step

3.

Go to step

7.

3

CHECK HARNESS.
1) Turn the ignition switch to OFF.
2) Disconnect all control module connectors
(i84, i10, i88, i85) that are connected to low
speed CAN communication line.
3) Using the tester, check for open, short
(power supply-output short, GND-output short)
in the harness.

Connector & terminal

(i84) No. 1 — (i10) No. 27 (combination
meter):
(i84) No. 9 — (i10) No. 26 (combination
meter):
(i84) No. 1 — (i88) No. 20 (auto A/C):
(i84) No. 9 — (i88) No. 19 (auto A/C):
(i84) No. 1 — (i85) No. 12 (audio):
(i84) No. 9 — (i85) No. 11 (audio):

Is harness normal?

Go to step

4.

Repair or replace
the harness.

4

CHECK AUDIO.
1) Connect the disconnected connectors.
2) Disconnect the connector of audio (i85).
3) Turn the ignition switch to ON.
4) Read the DTC of body integrated unit using
Subaru Select Monitor.

Is U1300 a current malfunc-
tion?

Go to step

5.

Replace the audio.
<Ref. to ET-6,
REMOVAL,
Audio.>

5

CHECK AUTO A/C CONTROL MODULE.
1) Turn the ignition switch to OFF.
2) Connect the audio connector.
3) Disconnect the auto A/C control module
connector (i88).
4) Turn the ignition switch to ON.
5) Read the DTC of body integrated unit using
Subaru Select Monitor.

Is U1300 a current malfunc-
tion?

Go to step

6.

Replace the auto
A/C control mod-
ule. <Ref. to AC-
31, REMOVAL,
Control Unit (Auto
A/C Model).>

6

CHECK BODY INTEGRATED UNIT.
1) Turn the ignition switch to OFF.
2) Connect the auto A/C control module.
3) Replace the body integrated unit of your
vehicle with the body integrated unit from other
vehicle, which is working normally.
4) Turn the ignition switch to ON.
5) Read the DTC of body integrated unit using
Subaru Select Monitor.

Is U1300 a current malfunc-
tion?

Replace the com-
bination meter.
<Ref. to IDI-16,
REMOVAL, Com-
bination Meter.>

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

7

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 U1300 a current malfunc-
tion?

Repair or replace
the harness.

Go to step

8.

8

CHECK CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector that is connected
to low speed CAN circuit.

Is there poor contact at discon-
nected connector?

Repair the connec-
tor terminal, or
replace harness.

Temporary com-
munication failure
occurs.

Step

Check

Yes

No

LAN(diag)-66

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

O: DTC U1301 CAN-LS COUNTER ABNORMAL

DTC DETECTING CONDITION:

Communication is unstable because of low speed CAN communication error.

TROUBLE SYMPTOM:

Display error may occur in fuel gauge because the CAN communication is not transmitted (sending/receiv-

ing) normally.

WIRING DIAGRAM:

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

Step

Check

Yes

No

1

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

Are there DTC U1300 or
U1302?

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 U1301 a current malfunc-
tion?

Go to step

3.

Go to step

9.

2

*

1

*

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

i88

i10

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

i77

1 2 3 4 5 6 7 8 9 10

i85

1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

2

*

2

*

2

*

2

*

1

*

1

*

1

*

1

*

11

12

AA

AA

AA

20

i85

i88

19

27

i10

26

i77

i84

1

9

LAN01360

BODY

INTEGRATED

UNIT

CAN JOINT

CONNECT

OR

COMBINATION

METER

AUDIO

: AUTO A/C

A/C

CONTROL

PANEL

: TERMINAL No. OPTIONAL ARRANGEMENT AMONG 1, 2, 3, 4 AND 5

: TERMINAL No. OPTIONAL ARRANGEMENT AMONG 6, 7, 8, 9 AND 10

LAN(diag)-67

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
(i84, i10, i88, i85) that are connected to low
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 U1301 a current malfunc-
tion?

Go to step

4.

Go to step

9.

4

CHECK HARNESS.
1) Turn the ignition switch to OFF.
2) Disconnect all control module connectors
(i84, i10, i88, i85) that are connected to low
speed CAN communication line.
3) Using the tester, check for open, short
(power supply-output short, GND-output short)
in the harness.

Connector & terminal

(i84) No. 1 — (i10) No. 27 (combination
meter):
(i84) No. 9 — (i10) No. 26 (combination
meter):
(i84) No. 1 — (i88) No. 20 (auto A/C):
(i84) No. 9 — (i88) No. 19 (auto A/C):
(i84) No. 1 — (i85) No. 12 (audio):
(i84) No. 9 — (i85) No. 11 (audio):

Is harness normal?

Go to step

5.

Repair or replace
the harness.

5

CHECK AUDIO.
1) Connect the disconnected connectors.
2) Disconnect the connector of audio (i85).
3) Turn the ignition switch to ON.
4) Read the DTC of body integrated unit using
Subaru Select Monitor.

Is U1301 a current malfunc-
tion?

Go to step

6.

Replace the audio.
<Ref. to ET-6,
REMOVAL,
Audio.>

6

CHECK AUTO A/C CONTROL MODULE.
1) Turn the ignition switch to OFF.
2) Connect the audio unit.
3) Disconnect the auto A/C control module
connector (i88).
4) Turn the ignition switch to ON.
5) Read the DTC of body integrated unit using
Subaru Select Monitor.

Is U1301 a current malfunc-
tion?

Go to step

7.

Replace the auto
A/C control mod-
ule. <Ref. to AC-
31, REMOVAL,
Control Unit (Auto
A/C Model).>

7

CHECK COMBINATION METER.
1) Turn the ignition switch to OFF.
2) Connect the disconnected connectors.
3) Perform the self-diagnosis of combination
meter. <Ref. to IDI-5, SELF-DIAGNOSIS,
INSPECTION, Combination Meter System.>

Is the self-diagnosis of combi-
nation meter OK?

Go to step

8.

Replace the com-
bination meter.
<Ref. to IDI-16,
REMOVAL, Com-
bination Meter.>

8

CHECK BODY INTEGRATED UNIT.
1) Turn the ignition switch to OFF.
2) Disconnect all control module connectors
(i84, i10, i88, i85) that are connected to low
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 U1301 a current malfunc-
tion?

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

Go to step

9.

Step

Check

Yes

No

LAN(diag)-68

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

9

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

Is U1301 a current malfunc-
tion?

Repair or replace
the harness.

Go to step

10.

10

CHECK CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect all control module connectors
(i84, i10, i88, i85) that are connected to low
speed CAN communication line.

Is there poor contact of connec-
tor terminal?

Repair the connec-
tor terminal, or
replace harness.

Temporary com-
munication failure
occurs.

Step

Check

Yes

No