Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 791

LAN(diag)-73

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

R: DTC U1321 CAN-LS METER NO-RECEIVE DATA

DTC DETECTING CONDITION:

Not received data from meter.

TROUBLE SYMPTOM:

Engine may not be started.

WIRING DIAGRAM:

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

Step

Check

Yes

No

1

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

Is U1300 or U1302 displayed? 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 U1321 a current malfunc-
tion?

Go to step

3.

Go to step

7.

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)-74

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 U1321 a current malfunc-
tion?

Go to step

4.

Go to step

7.

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

Is the self diagnosis normal?

Go to step

6.

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

6

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 U1321 a current malfunc-
tion?

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

Go to step

7.

7

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 U1321 a current malfunc-
tion?

Repair the poor
contact, open cir-
cuit of harness or
replace harness.

Go to step

8.

8

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.

It is possible that
temporary poor
communication
occurs.

Step

Check

Yes

No

LAN(diag)-75

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

S: DTC B1500 KEYLESS UART COM. MALFUNCTION

DTC DETECTING CONDITION:

Open or short circuit in keyless UART circuit

TROUBLE SYMPTOM:

Door lock does not operate with keyless.

WIRING DIAGRAM:

Keyless entry system <Ref. to WI-159, WIRING DIAGRAM, Keyless Entry 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.>

Is B1500 current malfunction? Go to step

2.

Go to step

7.

R221

1 2 3 4 5 6
7 8 9 10 11 12

*

1

*

2

: R221

: R80

*

1

*

2

5

6

4

11

3

7

i102

R167

1

i102

1 2 3 4

5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

i84

1 2

3 4

5 6

7 8

9 0

1

1

1

2

1

4

1

5

1

6

1

7

1

8

1

9

1

0

2

1

2

2

2

3

2

4

2

5

2

6

2

7

2

8

2

9

2

0

3

1

3

2

3

3

3

4

3

5

3

3

1

R80

2

1

3 4

5 6 7 8

i84

4

2

LAN00609

OT

TP

TP

:

OT

OT

TP

: OT

TP

TO POWER SUPPLY

CIRCUIT

BODY

INTEGRATED

UNIT

: WITH TPMS

: WITHOUT TPMS

: KEYLESS ENTRY CM

: TPMS & KEYLESS ENTRY CM

FB-11

M/B FUSE NO. 8

(B)

LAN(diag)-76

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

LAN SYSTEM (DIAGNOSTICS)

2

CHECK DTC.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from body inte-
grated unit and keyless entry control module.
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 B1500 current malfunction? Go to step

3.

Go to step

7.

3

CHECK HARNESS.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from body inte-
grated unit and keyless entry control module.
3) Using the tester, check for open, short
(power supply-output short, GND-output short)
in the harness.

Connector & terminal

Keyless entry CM

(i84) No. 24 — (R80) No. 3:

TPMS & keyless entry CM

(i84) No. 24 — (R221) No. 11:

Is harness normal?

Go to step

4.

Repair or replace
the harness.

4

CHECK HARNESS.
Using the tester, measure the voltage between
keyless entry control module and chassis
ground.

Connector & terminal

Keyless entry CM

(R80) No. 4 (+) — Chassis ground (–):

TPMS & keyless entry CM

(R221) No. 6 (+) — Chassis ground (–):

Is the voltage battery voltage? Go to step

5.

Check the power
supply circuit for
keyless entry con-
trol module.

5

CHECK HARNESS.
Using the tester, measure the resistance
between keyless entry control module and
chassis ground.

Connector & terminal

Keyless entry CM

(R80) No. 7 — Chassis ground:

TPMS & keyless entry CM

(R221) No. 5 — Chassis ground:

Is the resistance less than 10

Ω?

Go to step

6.

Repair or replace
the open circuit of
harness.

6

CHECK OPERATION.
1) Install the keyless entry control module from
other vehicle, which is working normally.
2) Register the keyless key which is working
normally.
3) Operate the keyless key.

Does the door locking operate? Replace the key-

less entry control
module. <Ref. to
SL-46, REMOVAL,
Keyless Entry Con-
trol Module.>

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

7

CHECK CONNECTOR.
Disconnect the connectors from body inte-
grated unit and keyless entry control module.

Is there poor contact of connec-
tor?

Repair the connec-
tor, or replace har-
ness.

Temporary com-
munication failure
occurs.

Step

Check

Yes

No