Subaru Legacy (2005 year). Manual - part 618

5AT(diag)-63

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. 24 — (B11) No. 17:
(B55) No. 17 — (B11) No. 3:
(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. 24 — Chassis ground:
(B55) No. 17 — 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 Fr/B 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 4th speed with checking current 
gear position using Subaru Select Monitor.
4) Check input signal of Fr/B 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) Shift to 4th speed with checking current 
gear position using Subaru Select Monitor.
4) Check input signal of Fr/B 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)-64

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. 17 — (T11) No. 9:
(T4) No. 3 — (T10) No. 11:

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

(T11) No. 9 — Transmission ground:
(T10) 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)-65

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

S: DTC P0753 SHIFT SOLENOID “A” ELECTRICAL

DTC DETECTING CONDITION:
Output signal circuit of front brake solenoid is open or shorted.
TROUBLE SYMPTOM:
Locked to 4th or 5th 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. 24 — (B11) No. 17:
(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-03184

B54

24

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

17

E

5

14

9

5AT(diag)-66

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

2

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

Connector & terminal

(B54) No. 24 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 3.

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

3

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. 17 — (T11) No. 9:

Is the resistance less than 1 
Ω?

Go to step 4.

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

4

CHECK HARNESS CONNECTOR BETWEEN 
TRANSMISSION AND CONTROL VALVE 
BODY.
Measure the resistance between transmission 
ground and control valve body connector.

Connector & terminal

(T11) No. 9 — Transmission ground:

Is the resistance more than 1 
M

Ω?

Go to step 5.

Repair the short 
circuit of harness 
between control 
valve body and 
transmission con-
nector.

5

CHECK FRONT BRAKE SOLENOID.
Measure the resistance between transmission 
ground and control valve body connector.

Connector & terminal

(T11) No. 9 — Transmission ground:

Is the resistance 3 — 9 

Ω

Go to step 6.

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

6

CHECK POOR CONTACT.
Check that there are no poor contact in TCM 
connector, transmission connector and control 
valve body connector.

Is there any loosing terminal, 
entering foreign matter, dam-
aging connector body?

Repair the poor 
contact.

Go to step 7.

7

CHECK AFTER REPAIR.
1) Perform the clear memory mode.
2) Drive for a while, read the DTC, and verify 
that there is no faulty.

Is DTC displayed?

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

Temporary poor 
contact or open 
circuit occurs. 
Recheck that the 
harness connec-
tor has no faulty.

Step

Check

Yes

No