Subaru Legacy (2005 year). Service manual - part 616

5AT(diag)-55

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

H: DTC P0725 ENGINE SPEED INPUT CIRCUIT

DTC DETECTING CONDITION:
Information of engine speed is not correctly received from ECM.
TROUBLE SYMPTOM:
No lock-up (after engine warm-up).

I:

DTC P0731 GEAR 1 INCORRECT RATIO

NOTE:
Refer to DTC P0736 for diagnostic procedure. <Ref. to 5AT(diag)-56, DTC P0736 REVERSE INCORRECT
RATIO, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

J: DTC P0732 GEAR 2 INCORRECT RATIO

NOTE:
Refer to DTC P0736 for diagnostic procedure. <Ref. to 5AT(diag)-56, DTC P0736 REVERSE INCORRECT
RATIO, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

K: DTC P0733 GEAR 3 INCORRECT RATIO

NOTE:
Refer to DTC P0736 for diagnostic procedure. <Ref. to 5AT(diag)-56, DTC P0736 REVERSE INCORRECT
RATIO, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

L: DTC P0734 GEAR 4 INCORRECT RATIO

NOTE:
Refer to DTC P0736 for diagnostic procedure. <Ref. to 5AT(diag)-56, DTC P0736 REVERSE INCORRECT
RATIO, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

M: DTC P0735 GEAR 5 INCORRECT RATIO

NOTE:
Refer to DTC P0736 for diagnostic procedure. <Ref. to 5AT(diag)-56, DTC P0736 REVERSE INCORRECT
RATIO, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

Step

Check

Yes

No

1

CHECK DTC OF ECM.

Is DTC of AT CAN communica-
tion circuit detected?

Perform the diag-
nosis according to 
DTC.

Go to step 2.

2

CHECK DTC OF TCM.

Is DTC of AT CAN communica-
tion circuit detected?

Perform the diag-
nosis according to 
DTC.

Go to step 3.

3

CHECK DTC OF TCM.

Is any of following DTC 
detected? / Output Speed Sen-
sor Circuit / AT Vehicle Speed 
Sensor Circuit Malfunction 
(Rear Wheel)

Perform the diag-
nosis according to 
DTC.

Replace the TCM. 
<Ref. to 5AT-61, 
Transmission Con-
trol Module 
(TCM).>

5AT(diag)-56

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

N: DTC P0736 REVERSE INCORRECT RATIO

DTC DETECTING CONDITION:
Vehicle speed sensor, torque converter turbine speed sensor or control valve malfunction
TROUBLE SYMPTOM:
• Shift point is too high or too low.
• Excessive shift shock
• Tight corner braking phenomenon is occurred.
• Gear is not shifted to reverse.
• Gear position is held by fail safe function.
• Vehicle does not run.

Step

Check

Yes

No

1

CHECK DTC OF TCM.

Is DTC P1799 displayed at the 
same time?

Perform the diag-
nosis according to 
DTC.

Go to step 2.

2

CHECK DTC OF TCM.

Is any of the DTC P0751, 
P0756, P0761, P0766 dis-
played at the same time?

Perform the diag-
nosis according to 
DTC.

Go to step 3.

3

CHECK DTC OF TCM.

Is any of the DTC P0705, 
P0715, P0720, P1706, P1710 
displayed at the same time?

Perform the diag-
nosis according to 
DTC.

Go to step 4.

4

CHECK TURBINE SPEED.
Check the indication of Subaru Select Monitor.

Is the indication changes 
according to acceleration, 
braking and shifting?

Go to step 5.

Perform the diag-
nosis according to 
DTC P0715, 
P1710.

5

CHECK FRONT AND REAR VEHICLE 
SPEED SENSOR.

Does the value of Subaru 
Select Monitor mostly match 
with indication of speed meter?

Go to step 6.

Perform the diag-
nosis according to 
DTC P0720, 
P1706.

6

CHECK INHIBITOR SWITCH.

Does the value of Subaru 
Select Monitor match with 
value of meter indicator?

Go to step 7.

Perform the diag-
nosis according to 
DTC P0705.

7

CHECK DTC OF TCM.
1) Perform the clear memory mode.
2) Perform the inspection mode. <Ref. to 
5AT(diag)-21, PROCEDURE, Inspection 
Mode.>

Is DTC displayed?

Perform the diag-
nosis according to 
DTC.

Go to step 8.

8

DRIVING CHECK.
Perform the road test. <Ref. to 5AT-31, 
INSPECTION, Road Test.>

NOTE:

When performing the test, do not exceed post-
ed speed limit.

Is malfunction corrected?

Temporary poor 
contact occurs. 
Check that the 
harness connec-
tor has no faulty.

Replace the trans-
mission assembly.

5AT(diag)-57

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

O: DTC P0741 TORQUE CONVERTER CLUTCH CIRCUIT PERFORMANCE OR 

STUCK OFF

DTC DETECTING CONDITION:
• Lock up clutch malfunction
• Valve anchoring
TROUBLE SYMPTOM:
No lock-up occurs. (After engine is warmed-up)

Step

Check

Yes

No

1

CHECK DTC OF TCM.

Is any of following DTC 
detected? / AT CAN Communi-
cation Circuit / Engine Speed 
Input Circuit / Input/Turbine 
Speed Sensor Circuit / Torque 
Converter Turbine 2 Speed 
Signal Circuit 2 Malfunction

Perform the diag-
nosis according to 
each DTC.

Go to step 2.

2

CHECK DTC OF TCM.
1) Perform clear memory mode. <Ref. to 
5AT(diag)-19, CLEAR MEMORY MODE, 
OPERATION, Subaru Select Monitor.>
2) Read DTC

Is DTC displayed?

Perform the diag-
nosis according to 
DTC.

Go to step 3.

3

CHECK INHIBITOR SWITCH CIRCUIT.
Diagnose according to DTC P0705 procedure.

Is there any trouble?

Repair or replace 
the inhibitor switch 
circuit.

Go to step 4.

4

CHECK STOP LIGHT SWITCH CIRCUIT.
Diagnose according to DTC P0719 and P0724 
procedure.

Is there any trouble?

Repair or replace 
the stop light 
switch circuit.

Go to step 5.

5

CHECK ATF TEMPERATURE SENSOR CIR-
CUIT.
Diagnose according to DTC P0712, P0713, 
P1716 and P1717 procedure.

Is there any trouble?

Repair or replace 
the ATF tempera-
ture sensor circuit.

There are mal-
functions in TCM, 
TCM connector 
poor contact, or 
transmission 
assembly mechan-
ical malfunction.

5AT(diag)-58

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

P: DTC P0743 TORQUE CONVERTER CLUTCH CIRCUIT ELECTRICAL

DTC DETECTING CONDITION:
The output signal circuit of lock up solenoid is open or shorted.
TROUBLE SYMPTOM:
No lock-up (after engine warm-up).
WIRING DIAGRAM:

Step

Check

Yes

No

1

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

Connector & terminal

(B54) No. 23 — (B11) No. 20:
(B54) No. 5 — Chassis ground:
(B54) No. 14 — Chassis ground:

Is the resistance less than 1 
Ω?

Go to step 2.

Repair the open 
circuit of harness 
between TCM con-
nector and trans-
mission connector.

AT-03181

B54

23

B11

T4

TCM

B54

B11

1 2

5

6 7

8

13

14 15

16

9 10

11 12

3 4

17 18

19 20

TRANSMISSION

1 2

7

8

9

5 6

3 4

10 11 12
19 20 21

13

14 15

16

17

18

22

23

24

6

T11

1 2
5

8

6

9 10 11

3 4

12

T11

7

20

5

14

E