Subaru Legacy (2005 year). Manual - part 619

5AT(diag)-67

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

T: DTC P0756 SHIFT SOLENOID “B” PERFORMANCE OR STUCK OFF

DTC DETECTING CONDITION:
Output signal value of input clutch solenoid and oil pressure does not match.
TROUBLE SYMPTOM:
Locked to 4th gear.
WIRING DIAGRAM:

AT-03185

B54

18

B11

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

T4

T11

1 2
5

8

6

9 10 11

3 4

12

T11

7

E

5

14

8

8

18

11

6

T10

1 2 3

6

8 9 10 11 12 13 14

4 5

15 16

T10

7

5AT(diag)-68

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

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. 18 — (B11) No. 18:
(B54) No. 6 — (B11) No. 11:
(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 and 
transmission con-
nector.

2

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

Connector & terminal

(B54) No. 18 — Chassis ground:
(B54) No. 6 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 3.

Repair the short 
circuit of harness 
between TCM and 
transmission con-
nector.

3

CHECK INPUT SIGNAL FOR TCM USING 
SUBARU SELECT MONITOR.
1) Connect all the connectors.
2) Turn the ignition switch to ON. (engine 
OFF)
3) Check input signal of I/C oil pressure SW.

Is OFF displayed?

Go to step 4.

Go to step 7.

4

CHECK INPUT SIGNAL FOR TCM USING 
SUBARU SELECT MONITOR.
1) Turn the ignition switch to OFF.
2) Turn the ignition switch to ON. (engine ON)
3) Shift to “D” range and brake ON (1st) with 
checking current gear position using Subaru 
Select Monitor.
4) Check input signal of I/C oil pressure SW.

Is OFF displayed?

Go to step 5.

Replace the con-
trol valve body. 
<Ref. to 5AT-58, 
Control Valve 
Body.>

5

CHECK INPUT SIGNAL FOR TCM USING 
SUBARU SELECT MONITOR.
1) Turn the ignition switch to OFF.
2) Turn the ignition switch to ON. (engine ON)
3) Drive the vehicle on 4th speed of “D” range 
with checking current gear position using Sub-
aru Select Monitor.
4) Check input signal of I/C oil pressure SW.

Is ON displayed?

Even if the SPORT 
indicator lights 
blinks, the system 
is in normal condi-
tion. A temporary 
poor contact of 
connector or har-
ness may be the 
cause. Repair the 
poor contact of 
harness in the 
solenoid output 
and oil pressure 
SW input.

Go to step 6.

5AT(diag)-69

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

6

CHECK HARNESS CONNECTOR BETWEEN 
TRANSMISSION AND CONTROL VALVE 
BODY.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from transmis-
sion.
3) Remove the transmission connector from 
bracket.
4) Jack-up the vehicle and place it on rigid 
racks.

NOTE:

Raise all wheels off floor.

5) Drain the ATF.

CAUTION:

Do not drain the ATF until it cools down.

6) Remove the oil pan, and disconnect the 
control valve body connector.
7) Measure the resistance between transmis-
sion connector and control valve body connec-
tor.

Connector & terminal

(T4) No. 18 — (T11) No. 8:
(T4) No. 11 — (T10) No. 8:

Is the resistance less than 1 
Ω?

Replace the trans-
mission assembly. 
<Ref. to 5AT-38, 
Automatic Trans-
mission Assem-
bly.>

Repair the open 
circuit of harness 
between control 
valve body con-
nector and trans-
mission connector.

7

CHECK HARNESS CONNECTOR BETWEEN 
TRANSMISSION AND CONTROL VALVE 
BODY.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from transmis-
sion.
3) Remove the transmission connector from 
bracket.
4) Jack-up the vehicle and place it on rigid 
racks.

NOTE:

Raise all wheels off floor.

5) Drain the ATF.

CAUTION:

Do not drain the ATF until it cools down.

6) Remove the oil pan, and disconnect the 
control valve body connector.
7) Measure the resistance between transmis-
sion ground and control valve body connector.

Connector & terminal

(T4) No. 18 — Transmission ground:
(T4) No. 11 — Transmission ground:

Is the resistance more than 1 
M

Ω?

Replace the con-
trol valve body. 
<Ref. to 5AT-58, 
Control Valve 
Body.>

Repair the short 
circuit of harness 
between control 
valve body con-
nector and trans-
mission connector.

Step

Check

Yes

No

5AT(diag)-70

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

U: DTC P0758 SHIFT SOLENOID “B” ELECTRICAL

DTC DETECTING CONDITION:
Output signal circuit of input clutch solenoid is open or shorted.
TROUBLE SYMPTOM:
Locked to 4th gear.
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. 18 — (B11) No. 18:
(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 and 
transmission con-
nector.

AT-03186

B54

18

B11

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

T4

T11

1 2
5

8

6

9 10 11

3 4

12

T11

7

E

5

14

8

18