Subaru Legacy (2005 year). Manual - part 550

4AT(diag)-37

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

13

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

Connector & terminal

(B54) No. 5 — (T7) No. 9:

Is the resistance less than 1 
Ω?

Go to step 14.

Repair the open 
circuit of harness 
between TCM and 
inhibitor switch 
connector, and 
poor contact in 
coupling connec-
tor.

14

CHECK INPUT SIGNAL FOR TCM.
1) Turn the ignition switch to OFF.
2) Connect the connector to TCM and inhibitor 
switch.
3) Turn the ignition switch to ON.
4) Shift the select lever to “P” range.
5) Measure the voltage between TCM and 
chassis ground.

Connector & terminal

(B54) No. 5 (+) — Chassis ground (

−

):

Is the voltage less than 1 V?

Go to step 15.

Go to step 41.

15

CHECK INPUT SIGNAL FOR TCM.
1) Shift the select lever to any range other 
than “P”.
2) Measure the voltage between TCM and 
chassis ground.

Connector & terminal

(B54) No. 5 (+) — Chassis ground (

−

):

Is the voltage more than 8 V?

Go to step 16.

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

16

CHECK BODY INTEGRATED MODULE.
Read the data of inhibitor switch from Subaru 
Select Monitor. <Ref. to LAN(diag)-14, OPER-
ATION, Subaru Select Monitor.>

Is 7 displayed?

Go to step 17.

Check the body 
integrated module. 

17

CHECK BODY INTEGRATED MODULE.
Check DTC of body integrated module.

Is DTC of CAN communication 
displayed?

Perform the diag-
nosis according to 
DTC.

Go to step 18.

18

CHECK COMBINATION METER.
Check the “P” range indicator light. <Ref. to 
IDI-3, INSPECTION, Combination Meter Sys-
tem.>

Is the “P” range indicator light 
OK?

Go to step 41.

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

19

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND INHIBITOR SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from TCM, 
inhibitor switch and combination meter.
3) Measure the resistance of harness 
between TCM connector and chassis ground.

Connector & terminal

(B54) No. 5 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 42.

Repair the ground 
short circuit in “P” 
range circuit.

20

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

Connector & terminal

(B54) No. 14 — (T7) No. 8:

Is the resistance less than 1 
Ω?

Go to step 21.

Repair the open 
circuit of harness 
between TCM and 
inhibitor switch 
connector, and 
poor contact in 
coupling connec-
tor.

Step

Check

Yes

No

4AT(diag)-38

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

21

CHECK INPUT SIGNAL FOR TCM.
1) Turn the ignition switch to OFF.
2) Connect the connector to TCM and inhibitor 
switch.
3) Turn the ignition switch to ON.
4) Shift the select lever to “R” range.
5) Measure the voltage between TCM and 
chassis ground.

Connector & terminal

(B54) No. 14 (+) — Chassis ground (

−

):

Is the voltage less than 1 V?

Go to step 22.

Go to step 41.

22

CHECK INPUT SIGNAL FOR TCM.
1) Shift the select lever to other than “R” 
range.
2) Measure the voltage between TCM and 
chassis ground.

Connector & terminal

(B54) No. 14 (+) — Chassis ground (

−

):

Is the voltage more than 8 V?

Go to step 41.

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

23

CHECK BODY INTEGRATED MODULE.
Read the data of shift position from Subaru 
Select Monitor. <Ref. to LAN(diag)-14, OPER-
ATION, Subaru Select Monitor.>

Is 6 displayed?

Go to step 24.

Check the body 
integrated module. 

24

CHECK BODY INTEGRATED MODULE.
Check DTC of body integrated module.

Is DTC of CAN communication 
displayed?

Perform the diag-
nosis according to 
DTC.

Go to step 25.

25

CHECK COMBINATION METER.
Check the “R” range indicator light. <Ref. to 
IDI-3, INSPECTION, Combination Meter Sys-
tem.>

Is the “R” range indicator light 
OK?

Go to step 41.

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

26

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND INHIBITOR SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from TCM, 
inhibitor switch and combination meter.
3) Measure the resistance of harness 
between TCM connector and chassis ground.

Connector & terminal

(B54) No. 14 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 41.

Repair the ground 
short circuit in “R” 
range circuit.

27

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

Connector & terminal

(B54) No. 22 — (T7) No. 10:

Is the resistance less than 1 
Ω?

Go to step 28.

Repair the open 
circuit of harness 
between TCM and 
inhibitor switch 
connector, and 
poor contact in 
coupling connec-
tor.

28

CHECK INPUT SIGNAL FOR TCM.
1) Turn the ignition switch to OFF.
2) Connect the connector to TCM and inhibitor 
switch.
3) Turn the ignition switch to ON.
4) Shift the select lever to “N” range.
5) Measure the voltage between TCM and 
chassis ground.

Connector & terminal

(B54) No. 22 (+) — Chassis ground (

−

):

Is the voltage less than 1 V?

Go to step 29.

Go to step 41.

Step

Check

Yes

No

4AT(diag)-39

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

29

CHECK INPUT SIGNAL FOR TCM.
1) Shift the select lever to other than “N” 
range.
2) Measure the voltage between TCM and 
chassis ground.

Connector & terminal

(B54) No. 22 (+) — Chassis ground (

−

):

Is the voltage more than 8 V?

Go to step 41.

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

30

CHECK BODY INTEGRATED MODULE.
Read the data of shift position from the Subaru 
Select Monitor. <Ref. to LAN(diag)-14, OPER-
ATION, Subaru Select Monitor.>

Is 5 displayed?

Go to step 31.

Check the body 
integrated module. 

31

CHECK BODY INTEGRATED MODULE.
Check DTC of body integrated module.

Is DTC of CAN communication 
displayed?

Perform the diag-
nosis according to 
DTC.

Go to step 32.

32

CHECK COMBINATION METER.
Check the “N” range indicator light. <Ref. to 
IDI-3, INSPECTION, Combination Meter Sys-
tem.>

Is the “N” range indicator light 
OK?

Go to step 41.

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

33

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND INHIBITOR SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from TCM, 
inhibitor switch and combination meter.
3) Measure the resistance of harness 
between TCM connector and chassis ground.

Connector & terminal

(B54) No. 22 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 41.

Repair the ground 
short circuit in “N” 
range circuit.

34

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

Connector & terminal

(B54) No. 4 — (T7) No. 3:

Is the resistance less than 1 
Ω?

Go to step 35.

Repair the open 
circuit of harness 
between TCM and 
inhibitor switch 
connector, and 
poor contact in 
coupling connec-
tor.

35

CHECK INPUT SIGNAL FOR TCM.
1) Turn the ignition switch to OFF.
2) Connect the connector to TCM and inhibitor 
switch.
3) Turn the ignition switch to ON.
4) Shift the select lever to “D” range.
5) Measure the voltage between TCM and 
chassis ground.

Connector & terminal

(B54) No. 4 (+) — Chassis ground (

−

):

Is the voltage less than 1 V?

Go to step 36.

Go to step 41.

36

CHECK INPUT SIGNAL FOR TCM.
1) Shift the select lever to other than “D” 
range.
2) Measure the voltage between TCM and 
chassis ground.

Connector & terminal

(B54) No. 4 (+) — Chassis ground (

−

):

Is the voltage more than 8 V?

Go to step 41.

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

37

CHECK BODY INTEGRATED MODULE.
Read the data of inhibitor switch from Subaru 
Select Monitor. <Ref. to LAN(diag)-14, OPER-
ATION, Subaru Select Monitor.>

Is 4 displayed?

Go to step 38.

Check the body 
integrated module. 

Step

Check

Yes

No

4AT(diag)-40

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

38

CHECK BODY INTEGRATED MODULE.
Check DTC of body integrated module.

Is DTC of CAN communication 
displayed?

Perform the diag-
nosis according to 
DTC.

Go to step 39.

39

CHECK COMBINATION METER.
Check the “D” range indicator light. <Ref. to 
IDI-3, INSPECTION, Combination Meter Sys-
tem.>

Is the “D” range indicator light 
OK?

Go to step 41.

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

40

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND INHIBITOR SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from TCM, 
inhibitor switch and combination meter.
3) Measure the resistance of harness 
between TCM connector and chassis ground.

Connector & terminal

(B55) No. 4 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 41.

Repair the ground 
short circuit in “D” 
range circuit.

41

CHECK POOR CONTACT.

Is there poor contact in inhibi-
tor switch circuit?

Repair the poor 
contact.

Go to step 42.

42

CHECK INHIBITOR SWITCH.

Is the inhibitor switch in normal 
position?

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

Adjust inhibitor 
switch and select 
cable. <Ref. to 
4AT-51, Inhibitor 
Switch.> <Ref. to 
CS-27, Select 
Cable.>

Step

Check

Yes

No