Subaru Legacy (2005 year). Manual - part 555

4AT(diag)-57

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

• RHD model

AT-03159

B64

B159

B280

B:

B281

C:

C23

B20

B30

8

B352

2

4

B53

B352

B53

10

9

8

7

6

5

4

3

2

1

20

19

18

17

16

15

14

13

12

11

B54

8

3

4

5

6

7

2

1

18 19 20

17

16

15

14

13

12

11

10

9

24

23

22

21

2

5

1

9

3

12

TCM

B54

MAIN SBF

SBF-2

No.8

E

B

A

TTER

Y

STOP LIGHT
SWITCH

JOINT
CONNECTOR

JOINT
CONNECTOR

JOINT
CONNECTOR

BODY INTEGRATED
MODULE

2

1

3 4

8

7

6

5

B159

2

1

3 4
8 9

7

6

5

B280

8

7

6

5

4

3

2

1

22

23

21

20

19

16

15

14

13

12

11

10

9

17

30

18

29

28

27

26

25

24

B281

8

7

6

5

4

3

2

1

21

22

20

19

16

15

14

13

12

11

10

9

17 18

28

27

26

25

24

23

B64

2

1

C:

B:

6

2

*

2

*

1

*

1

*

1

*

: TERMINAL No. RANDOM ARRANGEMENT
  AMONG 8,18, AND 19

2

*

 : TERMINAL No. RANDOM ARRANGEMENT
   AMONG 9,10, AND 20

4AT(diag)-58

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK DTC.

Does the DTC of CAN commu-
nication appear in the on-board 
diagnostics test mode?

Perform the diag-
nosis according to 
DTC.

Go to step 2.

2

CHECK BODY INTEGRATED MODULE.
1) Turn the ignition switch to OFF.
2) Connect the Subaru Select Monitor to data 
link connector.
3) Turn the ignition switch to ON. (engine 
OFF)
4) Turn the Subaru Select Monitor power 
switch to ON.
5) Read the data of brake pedal switch using 
Subaru Select Monitor. <Ref. to 4AT(diag)-16, 
OPERATION, Subaru Select Monitor.>

Is OFF displayed?

Go to step 3.

Go to step 4.

3

CHECK TCM.
Read the data of brake pedal switch using 
Subaru Select Monitor. <Ref. to 4AT(diag)-16, 
OPERATION, Subaru Select Monitor.>

Is OFF displayed?

A temporary poor 
contact of connec-
tor or harness may 
be the cause. 
Check the poor 
contact.

Replace the TCM. 
<Ref. to 4AT-66, 
Transmission Con-
trol Module 
(TCM).>

4

CHECK BODY INTEGRATED MODULE IN-
PUT SIGNAL.
1) Disconnect the harness connector of body 
integrated module.
2) Measure the voltage of harness between 
body integrated module and stop light switch.

Connector & terminal

(B281) No. 23 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Go to step 5.

Go to step 7.

5

CHECK STOP LIGHT SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from stop light 
switch.
3) Measure the resistance of harness 
between stop light switch terminals.

Terminal

LHD model (With cruise control)

No. 2 — No. 3:

LHD model (Without cruise control)

No. 1 — No. 2:

RHD model

No. 1 — No. 2:

Is the resistance more than 1 
M

Ω?

Go to step 6.

Replace the stop 
light switch.

6

CHECK HARNESS CONNECTOR BETWEEN 
BODY INTEGRATED MODULE AND STOP 
LIGHT SWITCH.
1) Turn the ignition switch to ON.
2) Measure the voltage of harness between 
body integrated module and chassis ground.

Connector & terminal

(B281) No. 23 (+) — Chassis ground (

−

):

Is the voltage less than 1 V?

Go to step 7.

Repair the short 
circuit of harness 
between TCM and 
stop light switch.

7

CHECK POOR CONTACT.

Is there poor contact in input 
signal of brake switch?

Repair the poor 
contact.

Check the body 
integrated module.

4AT(diag)-59

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

H: DTC P0725 ENGINE SPEED INPUT CIRCUIT

DTC DETECTING CONDITION:
Engine speed input signal circuit is open or shorted.
TROUBLE SYMPTOM:
• No lock-up occurs. (After engine is warmed-up)
• SPORT indicator light remains on when the vehicle speed is “0”.
WIRING DIAGRAM:

AT-01892

27

13

B134

ECM

B54

TCM

23

ND

HU

B54

1 2

7

8 9

5

6

3

4

10 11 12
19 20 21

13 14 15 16

17 18

22 23 24

B135

B134

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

:

:

: 

: 

ND

HU

B135

ND

HU

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

29 30 31

32 33

34 35

: 2.5 L EK AND 2.5 L K4 MODEL

: EXCEPT 2.5 L EK AND 2.5 L K4 MODEL

ND

HU

4AT(diag)-60

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from TCM and 
ECM.
3) Measure the resistance of harness 
between TCM and ECM.

Connector & terminal

2.5 L EK and 2.5 L K4 model

(B54) No. 13 — (B134) No. 23:

Except for 2.5 L EK and 2.5 L K4 model

(B54) No. 13 — (B135) No. 27:

Is the resistance less than 1 
Ω?

Go to step 2.

Repair the open 
circuit of harness 
between TCM and 
ECM connector.

2

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND ECM.
Measure the resistance of harness between 
TCM connector and chassis ground.

Connector & terminal

(B54) No. 13 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 3.

Repair the short 
circuit of harness 
between TCM and 
ECM connector.

3

CHECK INPUT SIGNAL FOR TCM USING 
SUBARU SELECT MONITOR.
1) Connect the connectors to TCM and ECM.
2) Connect the Subaru Select Monitor to data 
link connector.
3) Start the engine, and turn the Subaru 
Select Monitor power switch to ON.
4) Run the engine at idle.
5) Read the data of engine speed using Sub-
aru Select Monitor.
• Display shows engine speed signal value 
sent from ECM.

Is the revolution value same as 
the tachometer reading shown 
on the combination meter?

Even if the SPORT 
indicator light is 
blinking, the cir-
cuit has returned 
to normal condi-
tion at this time. A 
temporary poor 
contact of connec-
tor or harness may 
be the cause. 
Repair the har-
ness or connector 
in the TCM and 
ECM.

Go to step 4.

4

CHECK POOR CONTACT.

Is there poor contact in engine 
speed signal circuit?

Repair the poor 
contact.

Go to step 5.

5

CONFIRM DTC P0725.
Replace the ECM with a new one.

Does the DTC appear again, 
after the memory has been 
cleared?

Replace the TCM. 
<Ref. to 4AT-66, 
Transmission Con-
trol Module 
(TCM).>

Replace the ECM. 
<Ref. to FU(H4SO 
2.0)-34, Engine 
Control Module 
(ECM).>