Subaru Legacy (2005 year). Manual - part 634

5AT(diag)-127

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

AT:DTC P1840 TRANSMISSION FLUID PRESSURE SENSOR/SWITCH A CIR-

CUIT

DTC DETECTING CONDITION:
Front brake oil pressure switch malfunction
TROUBLE SYMPTOM:
Excessive shift shock

NOTE:
Refer to DTC P0751 for diagnostic procedure. <Ref. to 5AT(diag)-62, DTC P0751 SHIFT SOLENOID “A”
PERFORMANCE OR STUCK OFF, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

AU:DTC P1842 TRANSMISSION FLUID PRESSURE SENSOR/SWITCH C CIR-

CUIT

DTC DETECTING CONDITION:
Input clutch oil pressure switch malfunction
TROUBLE SYMPTOM:
Excessive shift shock

NOTE:
Refer to DTC P0756 for diagnostic procedure. <Ref. to 5AT(diag)-67, DTC P0756 SHIFT SOLENOID “B”
PERFORMANCE OR STUCK OFF, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

AV:DTC P1843 TRANSMISSION FLUID PRESSURE SENSOR/SWITCH D CIR-

CUIT

DTC DETECTING CONDITION:
Direct clutch oil pressure switch malfunction.
TROUBLE SYMPTOM:
Excessive shift shock

NOTE:
Refer to DTC P0766 for diagnostic procedure. <Ref. to 5AT(diag)-77, DTC P0766 SHIFT SOLENOID “D”
PERFORMANCE OR STUCK OFF, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

AW:DTC P1844 TRANSMISSION FLUID PRESSURE SENSOR/SWITCH E CIR-

CUIT

DTC DETECTING CONDITION:
High & low reverse clutch oil pressure switch malfunction.
TROUBLE SYMPTOM:
Excessive shift shock

NOTE:
Refer to DTC P0761 for diagnostic procedure. <Ref. to 5AT(diag)-72, DTC P0761 SHIFT SOLENOID “C”
PERFORMANCE OR STUCK OFF, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

8

CHECK SWITCH FOR SPORT MODE AND 
MANUAL MODE.
1) Shift the select lever to “P” range.
2) Measure the resistance between harness 
connector terminals of switch for SPORT mode 
and manual mode.

Terminal

(B116) No. 7 — No. 8

Is the resistance more than 1 
M

Ω?

Check the body 
integrated module.

Replace the select 
lever assembly. 
<Ref. to CS-22, 
Select Lever.>

Step

Check

Yes

No

5AT(diag)-128

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure without Diagnostic Trouble Code (DTC)

15.Diagnostic Procedure without Diagnostic Trouble Code (DTC)

A: CHECK MANUAL MODE SWITCH

DIAGNOSIS:
Input signal circuit of manual mode switch is open or shorted.
TROUBLE SYMPTOM:
Does not shift on manual mode.
WIRING DIAGRAM:

AT-03197

B54

TCM

4

3

A20

A30

5

9

6

10

B15

B25

E

B68

2

7

8

E

4

2

3

ST4

BODY INTEGRATED MODULE

B280

B281

B:

A:

SELECT
LEVER

B116

ROLL CONNECTOR

LH

RH

STEERING SHIFT SWITCH

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

B280

5

4

6 7

8

2

1

9

3

10

22

23

11 12 13 14 15

24 25

26 27

16 17 18

28 29

19 20

21

30

B281

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

B116

1 2

3 4

5 6 7 8 9 10

A:

B:

1

2 3

4 5 6 7 8

1

3

6 7 8

2

5

9 10

4

ST4

B68

TB

TB

MANUAL
MODE
SWITCH

UP

DOWN

UP

DOWN

UP

DOWN

5AT(diag)-129

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure without Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK BODY INTEGRATED MODULE.
1) Perform the ON/OFF operation on manual 
mode switch.
2) Read the data of manual mode switch sig-
nal using Subaru Select Monitor.

Both ON/OFF can be detected 
normally?

Go to step 2.

Go to step 7.

2

CHECK DTC OF BODY INTEGRATED MOD-
ULE.

Is DTC of AT CAN communica-
tion circuit detected?

Perform the diag-
nosis according to 
DTC.

Go to step 3.

3

CHECK TCM.
1) Perform the ON/OFF operation on manual 
mode switch.
2) Read the data of manual mode switch sig-
nal using Subaru Select Monitor.

Both ON/OFF can be detected 
normally?

Go to step 4.

Go to step 5.

4

CHECK SPORT INDICATOR LIGHT ON 
COMBINATION METER.

Is the SPORT indicator light 
OK?

Go to step 6.

Replace the com-
bination meter 
assembly. <Ref. to 
IDI-15, Combina-
tion Meter.>

5

CHECK DTC OF TCM.

Is DTC of AT CAN communica-
tion circuit detected?

Perform the diag-
nosis according to 
DTC.

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

6

CHECK DTC OF METER.

Is DTC of AT CAN communica-
tion circuit detected?

Perform the diag-
nosis according to 
DTC.

Replace the meter.

7

CHECK MANUAL MODE SWITCH GROUND 
CIRCUIT.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from manual 
mode switch.
3) Measure the resistance of harness 
between manual mode switch connector and 
chassis ground.

Connector & terminal

(B116) No. 6 — Chassis ground:

Is the resistance less than 1 
Ω?

Go to step 8.

Repair the open 
circuit of harness 
between manual 
mode switch and 
chassis ground.

8

CHECK MANUAL MODE SWITCH.
Measure the resistance between manual mode 
switch terminals.

Connector & terminal

(B116) No. 6 — No. 5:

Is the resistance more than 1 
M

Ω?

Go to step 9.

Replace the guide 
plate assembly.

9

CHECK MANUAL MODE SWITCH.
1) Shift the select lever to manual mode.
2) Measure the resistance between manual 
mode switch terminals.

Connector & terminal

(B116) No. 6 — No. 5:

Is the resistance less than 1 
Ω?

Go to step 10.

Replace the guide 
plate assembly.

10

CHECK HARNESS CONNECTOR BETWEEN 
BODY INTEGRATED MODULE AND MANU-
AL MODE SWITCH.
1) Disconnect the connector from body inte-
grated module.
2) Measure the resistance of harness 
between body integrated module connector 
and manual mode switch connector.

Connector & terminal

(B116) No. 5 — (B281) No. 15:

Is the resistance less than 1 
Ω?

Go to step 11.

Repair the open 
circuit of harness 
between manual 
mode switch con-
nector and TCM 
connector, or poor 
contact in connec-
tor.

5AT(diag)-130

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure without Diagnostic Trouble Code (DTC)

11

CHECK HARNESS CONNECTOR BETWEEN 
BODY INTEGRATED MODULE AND MANU-
AL MODE SWITCH.
1) Disconnect the connector from body inte-
grated module.
2) Measure the resistance of harness 
between manual mode switch connector and 
chassis ground.

Connector & terminal

(B116) No. 5 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 12.

Repair the short 
circuit of harness 
between manual 
mode switch con-
nector and TCM 
connector.

12

CHECK INPUT SIGNAL FOR TCM.
1) Connect all the connectors.
2) Turn the ignition switch to ON. (engine 
OFF)
3) Measure the signal voltage for TCM.

Connector & terminal

(B281) No. 15 (+) — Chassis ground (

−

):

Is the voltage more than 9 V?

Go to step 13.

Replace the body 
integrated mod-
ule. <Ref. to SL-
44, Body Inte-
grated Module.>

13

CHECK INPUT SIGNAL FOR TCM.
1) Shift and hold the select lever to up side.
2) Measure the signal voltage for TCM.

Connector & terminal

(B281) No. 15 (+) — Chassis ground (

−

):

Is the voltage less than 1 V?

Go to step 14.

Replace the body 
integrated mod-
ule. <Ref. to SL-
44, Body Inte-
grated Module.>

14

CHECK MANUAL MODE SWITCH GROUND 
CIRCUIT.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from manual 
mode switch.
3) Measure the resistance of harness 
between manual mode switch connector and 
chassis ground.

Connector & terminal

(B116) No. 10 — Chassis ground:

Is the resistance less than 1 
Ω?

Go to step 15.

Repair the open 
circuit of harness 
between manual 
mode switch and 
chassis ground.

15

CHECK MANUAL MODE SWITCH.
Measure the resistance between manual mode 
switch terminals.

Connector & terminal

(B116) No. 10 — No. 9:

Is the resistance more than 1 
M

Ω?

Go to step 16.

Replace the guide 
plate assembly.

16

CHECK MANUAL MODE SWITCH.
1) Shift the select lever to manual mode.
2) Measure the resistance between manual 
mode switch terminals.

Connector & terminal

(B116) No. 10 — No. 9:

Is the resistance less than 1 
Ω?

Go to step 17.

Replace the guide 
plate assembly.

17

CHECK HARNESS CONNECTOR BETWEEN 
BODY INTEGRATED MODULE AND MANU-
AL MODE SWITCH.
1) Disconnect the connector from body inte-
grated module.
2) Measure the resistance of harness 
between body integrated module connector 
and manual mode switch connector.

Connector & terminal

(B116) No. 9 — (B281) No. 25:

Is the resistance less than 1 
Ω?

Go to step 18.

Repair the open 
circuit of harness 
between manual 
mode switch con-
nector and body 
integrated module 
connector, or poor 
contact in connec-
tor.

Step

Check

Yes

No