Subaru Legacy (2005 year). Manual - part 559

4AT(diag)-73

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

4

CHECK OUTPUT SIGNAL EMITTED FROM 
TCM USING SUBARU SELECT MONITOR.
1) Connect all the connectors.
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) Warm-up the transmission until the ATF 
temperature exceeds approx. 80

°C (176°F).

NOTE:

If the ambient temperature is below 0

°C (32°F),

drive the vehicle until the ATF reaches its oper-
ating temperature.

5) Stop the engine and turn the ignition switch 
to ON (engine OFF).
6) Shift the select lever to “N” range, and 
depress the accelerator pedal.
7) Read the data of 2-4 brake duty solenoid 
using Subaru Select Monitor.
• 2-4 brake duty solenoid is indicated in “%”.

Is the value 100%?

Go to step 5.

Go to step 6.

5

CHECK OUTPUT SIGNAL EMITTED FROM 
TCM USING SUBARU SELECT MONITOR.
Shift the select lever to 2nd on manual mode.

Is the value 0%?

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 TCM and trans-
mission.

Go to step 6.

6

CHECK POOR CONTACT.

Is there poor contact in 2-4 
brake duty solenoid circuit?

Repair the poor 
contact.

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

7

CHECK 2-4 BRAKE DUTY SOLENOID (IN 
TRANSMISSION).
1) Remove the transmission connector from 
bracket.
2) Drain the ATF.

CAUTION:

Do not drain ATF until it cools down.

3) Remove the oil pan, and disconnect the 
connector from 2-4 brake duty solenoid.
4) Measure the resistance of harness 
between 2-4 brake duty solenoid connector 
and transmission ground.

Connector & terminal

(AT3) No. 6 — Transmission ground:

Is the resistance 2.0 — 6.0 

Ω? Go to step 8.

Replace the con-
trol valve body. 
<Ref. to 4AT-62, 
Control Valve 
Body.>

Step

Check

Yes

No

4AT(diag)-74

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

8

CHECK HARNESS CONNECTOR BETWEEN 
2-4 BRAKE DUTY SOLENOID AND TRANS-
MISSION.
Measure the resistance of harness between 2-
4 brake duty solenoid and transmission con-
nector.

Connector & terminal

(T4) No. 3 — (AT3) No. 6:

Is the resistance less than 1 
Ω?

Go to step 9.

Repair the open 
circuit of harness 
between 2-4 brake 
duty solenoid and 
transmission con-
nector.

9

CHECK HARNESS CONNECTOR BETWEEN 
2-4 BRAKE DUTY SOLENOID AND TRANS-
MISSION.
Measure the resistance of harness between 
transmission connector and transmission 
ground.

Connector & terminal

(T4) No. 3 — Transmission ground:

Is the resistance more than 1 
M

Ω?

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 2-4 brake duty 
solenoid and 
transmission.

Repair the short 
circuit of harness 
between 2-4 brake 
duty solenoid and 
transmission con-
nector.

Step

Check

Yes

No

4AT(diag)-75

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

S: DTC P0763 SHIFT SOLENOID “C” ELECTRICAL

DTC DETECTING CONDITION:
Output signal circuit of high clutch duty solenoid is open or shorted.
TROUBLE SYMPTOM:
Excessive shift shock
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

(B55) No. 8 — (B11) No. 7:

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 TRANSMISSION.
Measure the resistance of harness connector 
between TCM connector and chassis ground.

Connector & terminal

(B55) No. 8 — 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 HIGH CLUTCH DUTY SOLENOID.
Measure the resistance between transmission 
connector receptacle’s terminals.

Connector & terminal

(T4) No. 7 — No. 20:

Is the resistance 2.0 — 6.0 

Ω? Go to step 4.

Go to step 7.

AT-01489

B11

B55

AT3

1

2

3 4

5

6 7

8

9

13

14 15

20

19

17

16

10

11 12

18

8

B55

B11

AT3

T4

TCM

7

3

1

2

7

8

9

5

6

3

4

10 11 12

19 20 21

29 30 31

13 14 15 16 17

27 28

18

22 23 24 25 26

1

3

4 5 6

2

TRANSMISSION

HIGH CLUTCH
DUTY
SOLENOID

4AT(diag)-76

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

4

CHECK OUTPUT SIGNAL EMITTED FROM 
TCM USING SUBARU SELECT MONITOR.
1) Connect the connectors to TCM and trans-
mission.
2) Lift-up the vehicle.

NOTE:

Raise all wheels off floor.

3) Connect the Subaru Select Monitor to data 
link connector.
4) Start the engine, and turn the Subaru 
Select Monitor power switch to ON.
5) Start the engine and warm-up the engine 
until the ATF temperature exceeds 80

°C 

(176

°F).

NOTE:

If the ambient temperature is below 0

°C (32°F),

drive the vehicle until the ATF reaches its oper-
ating temperature.

6) Read the data of high clutch duty solenoid 
using Subaru Select Monitor.
• High clutch duty solenoid is indicated in “%”.
7) Shift the select lever to “D”, and slowly 
increase vehicle speed at 3rd or 4th to mea-
sure.

NOTE:

The speed difference between front and rear
wheels may light the ABS warning light or VDC
warning light, but this indicates no malfunction.
When AT control diagnosis is finished, perform
the ABS memory clearance procedure or VDC
memory clearance procedure of on-board diag-
nostics system. <Ref. to ABS(diag)-26, Clear
Memory Mode.> <Ref. to VDC(diag)-25, Clear
Memory Mode.>

Is the value 0%?

Go to step 5.

Go to step 6.

5

CHECK OUTPUT SIGNAL EMITTED FROM 
TCM USING SUBARU SELECT MONITOR.
Return the engine to idling speed and shift the 
select lever to “N” range.

NOTE:

The speed difference between front and rear
wheels may light the ABS warning light or VDC
warning light, but this indicates no malfunction.
When AT control diagnosis is finished, perform
the ABS memory clearance procedure or VDC
memory clearance procedure of on-board diag-
nostics system. <Ref. to ABS(diag)-26, Clear
Memory Mode.> <Ref. to VDC(diag)-25, Clear
Memory Mode.>

Is the value 100%?

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 TCM and trans-
mission.

Go to step 6.

6

CHECK POOR CONTACT.

Is there poor contact in high 
clutch duty solenoid circuit?

Repair the poor 
contact.

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

Step

Check

Yes

No