Subaru Legacy IV (2008 year). Manual — part 701

4AT(diag)-25

AT OIL TEMP Warning Light Display

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK ATF TEMPERATURE WARNING
LIGHT.
Turn the ignition switch to ON.

Does the ATF temperature
warning light illuminate?

Go to step 2.

Perform the self-
diagnosis of com-
bination meter.

2

CHECK ATF TEMPERATURE WARNING
LIGHT.
After the ignition switch is ON, wait for 2 sec-
onds or more.

Does the ATF temperature
warning light illuminate?

Go to step 3.

Go to step 4.

3

CHECK ATF TEMPERATURE WARNING
LIGHT.
Start the engine.

Does the ATF temperature
warning light go off?

Normal. Go back to
Basic Diagnostic
Procedure. <Ref.
to 4AT(diag)-2,
Basic Diagnostic
Procedure.>

Go to step 7.

4

CHECK SUBARU SELECT MONITOR COM-
MUNICATION.
Connect the Subaru Select Monitor to data link
connector.

Is the communication between
Subaru Select Monitor and
TCM normal?

Go to step 5.

Check the power
supply ground cir-
cuit of TCM and
Subaru Select
Monitor communi-
cation. <Ref. to
4AT(diag)-26,
Diagnostic Proce-
dure for Subaru
Select Monitor
Communication.>

5

CHECK TCM.
Display the current data of TCM using Subaru
Select Monitor.

Is the “Diagnosis Light” output
signal “ON”?

Go to step 6.

Replace the TCM.
<Ref. to 4AT-61,
Transmission Con-
trol Module
(TCM).>

6

CHECK BODY INTEGRATED UNIT.
Display current data of the body integrated unit
using the Subaru Select Monitor. <Ref. to
LAN(diag)-12, OPERATION, Subaru Select
Monitor.>

Is the “ATF Temperature Lamp”
input signal on “Illuminate”?

Replace the com-
bination meter
assembly. <Ref. to
IDI-22, Combina-
tion Meter.>

Check DTC of
body integrated
unit. <Ref. to
LAN(diag)-12,
OPERATION, Sub-
aru Select Moni-
tor.>

7

CHECK TCM.
Display the current data of TCM using Subaru
Select Monitor. <Ref. to 4AT(diag)-16, OPERA-
TION, Subaru Select Monitor.>

Is the “Diagnosis Light” output
signal “ON”?

Replace the TCM.
<Ref. to 4AT-61,
Transmission Con-
trol Module
(TCM).>

Go to step 8.

8

CHECK BODY INTEGRATED UNIT.
Display current data of the body integrated unit
using the Subaru Select Monitor. <Ref. to
LAN(diag)-12, OPERATION, Subaru Select
Monitor.>

Is the “ATF Temperature Lamp”
input signal on “Illuminate”?

Check DTC of
body integrated
unit. Perform the
diagnosis accord-
ing to DTC. <Ref.
to LAN(diag)-12,
OPERATION, Sub-
aru Select Moni-
tor.>

Perform the self-
diagnosis of com-
bination meter.
<Ref. to IDI-5,
INSPECTION,
Combination Meter
System.>

4AT(diag)-26

Diagnostic Procedure for Subaru Select Monitor Communication

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

11.Diagnostic Procedure for Subaru Select Monitor Communication

A: COMMUNICATION FOR INITIALIZING IMPOSSIBLE

DIAGNOSIS:
Defective harness connector
TROUBLE SYMPTOM:
Subaru Select Monitor communication failure
WIRING DIAGRAM:

B40

16

5

7

4

E

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16

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

No. 13

SBF-6

B40

B55

B11

T4

TCM

25

1

2

8

E

E

B11

1

2

3 4

5

6 7

8

9

13

14 15

20

19

17

16

10

11 12

18

19

20

A:

C:

27

26

B134

8

7

6

5

4

3

2

1

22 23

21

20

19

16

15

14

13

12

11

10

9

34 35

33

32

17
30

18
31

29

28

27

26

25

24

B136

5

6

7 8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26 27

28

16

17 18 19 20 21

33 34

29

32

30

31

35

23

22

20

21

B55

E

B134

A:

B136

C:

ECM

C6

A5

36

B21

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

42

43

36

37

38

39

48

49

50

51

52

53

54

40

41

44

45

46

47

B21

E2

AT-04897

CONTROL VALVE BODY

IGNITION

SWITCH

BATTERY

DATA LINK
CONNECTOR

M/B No.

12

F/B No.

12

MAIN SBF

4AT(diag)-27

Diagnostic Procedure for Subaru Select Monitor Communication

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK INSTALLATION OF TCM CONNEC-
TOR.
Turn the ignition switch to OFF.

Is TCM connector connected to
TCM?

Go to step 2.

Connect the TCM
connector to TCM.

2

CHECK SUBARU SELECT MONITOR POW-
ER SUPPLY CIRCUIT.
Measure the voltage between data link connec-
tor and chassis ground.

Connector & terminal

(B40) No. 16 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Go to step 3.

Repair harness
connector between
the battery and
data link connec-
tor, and poor con-
tact of the
connector.

3

CHECK SUBARU SELECT MONITOR
GROUND CIRCUIT.
1) Disconnect the connectors from ECM.
2) Measure the resistance of harness between
data link connector and ECM.

Connector & terminal

(B40) No. 4 — (B136) No. 6:
(B40) No. 5 — (B136) No. 6:

Is the resistance less than 1

:? Go to step 4.

Repair the open
circuit of harness
between data link
connector and
ECM.

4

CHECK SUBARU SELECT MONITOR
GROUND CIRCUIT.
Measure the resistance of harness between
data link connector and chassis ground.

Connector & terminal

(B40) No. 4 — Chassis ground:
(B40) No. 5 — Chassis ground:

Is the resistance 1 M

: or

more?

Go to step 5.

Repair the short
circuit of harness
between data link
connector and
ground terminals.

5

CHECK ENGINE GROUND CIRCUIT.
Check the engine ground circuit.

Is the engine ground circuit nor-
mal?

Go to step 6.

Repair ground cir-
cuit of ECM.

6

CHECK COMMUNICATION OF SUBARU SE-
LECT MONITOR.
1) Turn the ignition switch to ON.
2) Using the Subaru Select Monitor, check
whether communication to transmission system
can be executed normally.

Is the name of system dis-
played on Subaru Select Moni-
tor?

Go to step 11.

Go to step 7.

7

CHECK COMMUNICATION OF SUBARU SE-
LECT MONITOR.
1) Turn the ignition switch to OFF.
2) Disconnect the TCM connector.
3) Check whether communication to engine
system can be executed normally.

Is the name of system dis-
played on Subaru Select Moni-
tor?

Go to step 9.

Go to step 8.

8

CHECK COMMUNICATION OF SUBARU SE-
LECT MONITOR.
1) Turn the ignition switch to OFF.
2) Connect the TCM connector.
3) Disconnect the connectors of TPM control
unit, airbag control module, body integrated
unit, and ABSCM&H/U.

CAUTION:
When disconnecting the connector from air-
bag control module, always follow the pre-
cautions on AB section. <Ref. to AB-4,
CAUTION, General Description.>
4) Turn the ignition switch to ON.
5) Check whether communication to transmis-
sion system can be executed normally.

Is the name of system dis-
played on Subaru Select Moni-
tor?

Check each control
module.

Go to step 9.

4AT(diag)-28

Diagnostic Procedure for Subaru Select Monitor Communication

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

9

CHECK HARNESS CONNECTOR BETWEEN
EACH CONTROL MODULE AND DATA LINK
CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors of TCM, ECM,
TPM control unit, airbag control module, body
integrated unit, and ABSCM&H/U.
3) Measure the resistance between TCM con-
nector and chassis ground.

Connector & terminal

(B40) No. 7 — Chassis ground:

Is the resistance 1 M

: or

more?

Go to step 10.

Check harness
and connector
between each con-
trol module and
data link connec-
tor.

10

CHECK OUTPUT SIGNAL OF TCM.
1) Turn the ignition switch to ON.
2) Measure the voltage between TCM and
chassis ground.

Connector & terminal

(B40) No. 7 (+) — Chassis ground (–):

Is the voltage 1 V or more?

Check harness
and connector
between each con-
trol module and
data link connec-
tor.

Go to step 11.

11

CHECK HARNESS CONNECTOR BETWEEN
TCM AND DATA LINK CONNECTOR.
Measure the resistance between TCM connec-
tor and data link connector.

Connector & terminal

(B55) No. 8 — (B40) No. 7:

Is the resistance less than 1

:? Go to step 12.

Repair the harness
and connector
between TCM and
data link connec-
tor.

12

CHECK INSTALLATION OF TRANSMISSION
HARNESS CONNECTOR.

Is the transmission harness
connector connected to bulk-
head harness connector?

Go to step 13.

Connect the bulk-
head harness con-
nector to
transmission har-
ness connector.

13

CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in control

module power supply and data
link connector?

Repair the poor
contact.

Go to step 14.

14

CHECK POWER SUPPLY OF TCM.
1) Disconnect the connector from TCM.
2) Turn the ignition switch to ON.
3) Measure the voltage between TCM connec-
tor and chassis ground.

Connector & terminal

(B55) No. 27 (+) — Chassis ground (–):
(B55) No. 26 (+) — Chassis ground (–):
(B55) No. 25 (+) — Chassis ground (–):

Is the voltage 10 — 13 V?

Go to step 16.

Go to step 15.

15

CHECK FUSE (NO. 12).
1) Turn the ignition switch to OFF.
2) Remove the fuse (M/B No. 12).

Is the fuse (No. 12) blown out? Replace the fuse

(No. 12). If the
replaced fuse (No.
12) has blown out
easily, repair short
circuit of harness
between fuse (No.
12) and TCM.

Repair the open
circuit of harness
between fuse (No.
12) and TCM, or
fuse (No. 12) and
battery, and poor
contact of the con-
nector.

16

CHECK IGNITION POWER SUPPLY CIR-
CUIT.
1) Turn the ignition switch to ON (engine OFF).
2) Measure the ignition power supply voltage
between TCM connector and chassis ground.

Connector & terminal

(B55) No. 1 (+) — Chassis ground (–):
(B55) No. 2 (+) — Chassis ground (–):

Is the voltage 10 — 13 V?

Go to step 18.

Go to step 17.

Step

Check

Yes

No