Subaru Legacy (2005 year). Manual - part 541

AUTOMATIC TRANSMISSION
(DIAGNOSTICS)

4AT(diag)

Page

1.

Basic Diagnostic Procedure ........................................................................2

2.

Check List for Interview...............................................................................4

3.

General Description ....................................................................................5

4.

Electrical Component Location ...................................................................7

5.

Transmission Control Module (TCM) I/O Signal .......................................13

6.

Subaru Select Monitor...............................................................................16

7.

Read Diagnostic Trouble Code (DTC) ......................................................19

8.

Inspection Mode........................................................................................20

9.

Clear Memory Mode..................................................................................21

10.

SPORT Indicator Light Display .................................................................22

11.

Diagnostic Procedure for Subaru Select Monitor Communication ............26

12.

List of Diagnostic Trouble Code (DTC) .....................................................31

13.

Diagnostic Procedure with Diagnostic Trouble Code (DTC) .....................33

14.

Diagnostic Procedure without Diagnostic Trouble Code (DTC) ..............119

15.

Diagnostics with Phenomenon................................................................134

4AT(diag)-2

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Basic Diagnostic Procedure

1. Basic Diagnostic Procedure

A: PROCEDURE

Step

Check

Yes

No

1

CHECK PRE-INSPECTION.
1) Ask the customer when and how the trou-
ble occurred using the interview checklist. 
<Ref. to 4AT(diag)-4, Check List for Interview.>
2) Before performing diagnosis, inspect the 
following items which might influence the AT 
problems.
• General inspection <Ref. to 4AT(diag)-5, 
INSPECTION, General Description.>
• Disconnection of harness connector
• Visual check for harness damage
• Oil leakage
• Stall speed test <Ref. to 4AT-35, Stall Test.>
• Line pressure test <Ref. to 4AT-37, Line 
Pressure Test.>
• Transfer clutch pressure test <Ref. to 4AT-
38, Transfer Clutch Pressure Test.>
• Time lag test <Ref. to 4AT-36, Time Lag 
Test.>
• Road test <Ref. to 4AT-34, Road Test.>
• Inhibitor switch <Ref. to 4AT-51, Inhibitor 
Switch.>

Is the unit that might influence 
the AT problem normal?

Go to step 2.

Repair or replace 
each item.

2

CHECK SPORT INDICATOR LIGHT.
After starting the engine, wait for at least 2 sec-
onds.

Does the SPORT indicator 
light blink?

Go to step 4.

Go to step 3.

3

CHECK SPORT INDICATOR LIGHT.
1) Turn the ignition switch to OFF.
2) Check the SPORT indicator light.
<Ref. to 4AT(diag)-23, INSPECTION, SPORT 
Indicator Light Display.>
3) After the ignition switch is turned to “ON”, 
wait for at least 2 seconds.
4) Start the engine.

Does the SPORT indicator 
light blink?

Go to step 4.

Go to step 5.

4

CHECK INDICATION OF DTC.
Display DTC.

NOTE:

If the communication function of Subaru Select
Monitor cannot be executed normally, check
communication circuit. <Ref. to 4AT(diag)-26,
COMMUNICATION FOR INITIALIZING IM-
POSSIBLE, Diagnostic Procedure for Subaru
Select Monitor Communication.>

Is DTC displayed on the Sub-
aru Select Monitor?

Go to step 6.

NOTE:
Record all DTC.

Go to step 5.

5

PERFORM GENERAL DIAGNOSTICS.
1) Inspect using “Diagnostic Procedure with-
out Diagnostic Trouble Code (DTC)”. <Ref. to 
4AT(diag)-119, Diagnostic Procedure without 
Diagnostic Trouble Code (DTC).>
2) Inspect using “Diagnostics with Phenome-
non”. <Ref. to 4AT(diag)-134, Diagnostics with 
Phenomenon.>
3) Perform the inspection mode. <Ref. to 
4AT(diag)-20, Inspection Mode.>
4) Display DTC.

Is DTC displayed on the Sub-
aru Select Monitor?

Go to step 6.

Finish the diagno-
sis.

4AT(diag)-3

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Basic Diagnostic Procedure

6

PERFORM DIAGNOSIS.
1) Inspect using the “Diagnostic Procedure 
with Diagnostic Trouble Code (DTC)”. <Ref. to 
4AT(diag)-33, Diagnostic Procedure with Diag-
nostic Trouble Code (DTC).>

NOTE:

For DTC table, refer to “List of Diagnostic Trou-
ble Code (DTC)”. <Ref. to 4AT(diag)-31, List of
Diagnostic Trouble Code (DTC).>

2) Repair the trouble cause.
3) Perform the clear memory mode.
4) Perform the inspection mode. <Ref. to 
4AT(diag)-20, Inspection Mode.>
5) Display DTC.

Is DTC displayed on the Sub-
aru Select Monitor?

Inspect using the 
“Diagnostic Proce-
dure with Diagnos-
tic Trouble Code 
(DTC)”. <Ref. to 
4AT(diag)-33, 
Diagnostic Proce-
dure with Diagnos-
tic Trouble Code 
(DTC).>

Finish the diagno-
sis.

Step

Check

Yes

No

4AT(diag)-4

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Check List for Interview

2. Check List for Interview

A: CHECK

Check the following items when problem has occurred.

NOTE:
Use copies of this page for interviewing customers.

Customer’s name

Date of sale

Date of repair

Trans. model

Transmission

V.I.N.

Odometer reading

km (miles)

Frequency

❏ Continuous  ❏ Intermittent (

 times a day)

Weather

❏ Fine  ❏ Cloudy  ❏ Rainy  ❏ Snowy

❏ Others
(

)

Place

❏ Highland  ❏ Suburbs  ❏ Inner city  ❏ Uphill  ❏ Rough road

❏ Others
(

)

Ambient air temperature

❏ Hot  ❏ Warm  ❏ Cool  ❏ Cold

Vehicle speed

km/h (MPH)

AT warning light (SPORT indicator 
light)

❏ Blinks continuously

❏ Not blink

Select lever position

❏ P  ❏ R  ❏ N  ❏ D  ❏ SPORT mode

Driving condition

❏ Not affected

❏ At racing

❏ When decelerating

❏ At starting

❏ When accelerating

❏ While turning (❏ RH/❏ 
LH)

❏ While idling

❏ While cruising

SPORT mode

❏ ON  ❏ OFF

Symptom

❏ No up-shift
❏ No down-shift
❏ No kick down
❏ Vehicle does not move (❏ Any position  ❏ Particular position)
❏ Lock-up malfunction
❏ Noise or vibration
❏ Shift shock or slip
❏ Select lever does not move
❏ Others
(

)