Subaru Legacy (2005 year). Manual - part 575

4AT(diag)-137

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostics with Phenomenon

Shock occurs from 2nd to 3rd gear.

• TCM
• Torque converter turbine speed sensor
• Accelerator pedal position sensor
• 2-4 brake duty solenoid
• ATF temperature sensor
• Line pressure linear solenoid
• Low & reverse duty solenoid
• Control valve
• High clutch
• 2-4  brake
• ATF deterioration
• Engine performance
• High clutch duty solenoid

Slippage occurs from 2nd to 3rd gear.

• TCM
• Accelerator pedal position sensor
• 2-4 brake duty solenoid
• ATF temperature sensor
• Line pressure linear solenoid
• Control valve
• High clutch
• 2-4  brake
• Low & reverse duty solenoid

Shock occurs from 3rd to 4th gear.

• TCM
• Torque converter turbine speed sensor
• Accelerator pedal position sensor
• 2-4 brake duty solenoid
• ATF temperature sensor
• Line pressure linear solenoid
• Control valve
• Low clutch duty solenoid
• 2-4  brake
• ATF deterioration
• Engine performance

Slippage occurs from 3rd to 4th gear.

• TCM
• Accelerator pedal position sensor
• 2-4 brake duty solenoid
• ATF temperature sensor
• Line pressure linear solenoid
• Control valve
• 2-4  brake

Shock occurs when select lever is shifted from 3rd gear to 2nd 
gear.

• TCM
• Torque converter turbine speed sensor
• Accelerator pedal position sensor
• ATF temperature sensor
• Line pressure linear solenoid
• Control valve
• 2-4 brake duty solenoid
• 2-4  brake
• ATF deterioration
• High clutch duty solenoid

Shock occurs when select lever is shifted from 2nd gear to 1st 
gear.

• TCM
• Torque converter turbine speed sensor
• Accelerator pedal position sensor
• ATF temperature sensor
• Line pressure linear solenoid
• Control valve
• Low & reverse clutch
• ATF deterioration
• 2-4 brake duty solenoid
• Low & reverse brake duty solenoid

Symptom

Faulty parts

4AT(diag)-138

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostics with Phenomenon

Shock occurs when accelerator pedal is released at medium 
speeds.

• TCM
• Accelerator pedal position sensor
• ATF temperature sensor
• Line pressure linear solenoid
• Control valve
• Lock-up damper
• Engine performance

Vibration occurs during straight-forward operation.

• TCM
• Lock-up duty solenoid
• Lock-up facing
• Lock-up damper

Vibration occurs during turns. (tight corner braking phenome-
non)

• TCM
• Front vehicle speed sensor
• Rear vehicle speed sensor
• Accelerator pedal position sensor
• ATF temperature sensor
• Transfer  clutch
• Transfer  valve
• Transfer duty solenoid
• ATF deterioration
• Harness

Front wheel slippage occurs during standing starts.

• TCM
• Front vehicle speed sensor
• Accelerator pedal position sensor
• ATF temperature sensor
• Control valve
• Transfer  clutch
• Transfer  valve
• Transfer pipe
• Transfer duty solenoid

It is not set in FWD mode.

• TCM
• Transfer  clutch
• Transfer  valve
• Transfer duty solenoid

Select lever is hard to move.

• Select cable
• Select lever
• Detent spring
• Manual plate

Select lever is excessively hard to move. (unreasonable resis-
tance)

• Detent spring
• Manual plate

Select lever slips out of operation during acceleration or while 
driving on rough terrain.

• Select cable
• Select lever
• Detent spring
• Manual plate

Can not set to manual mode.

• SPORT mode switch
• TCM
• Body integrated module

Gear does not change though the select lever is operated in 
manual mode.

• Up shift switch
• Down shift switch
• TCM
• Body integrated module

Symptom

Faulty parts

AUTOMATIC TRANSMISSION

5AT

Page

1.

General Description ....................................................................................2

2.

Automatic Transmission Fluid ...................................................................28

3.

Differential Gear Oil...................................................................................30

4.

Road Test..................................................................................................31

5.

Stall Test ...................................................................................................32

6.

Time Lag Test ...........................................................................................34

7.

Line Pressure Test ....................................................................................35

8.

Transfer Clutch Pressure Test ..................................................................36

9.

Automatic Transmission Assembly ...........................................................38

10.

Transmission Mounting System ................................................................47

11.

Extension Case Oil Seal ...........................................................................49

12.

Differential Side Retainer Oil Seal.............................................................50

13.

Inhibitor Switch..........................................................................................51

14.

Front Vehicle Speed Sensor .....................................................................52

15.

Rear Vehicle Speed Sensor......................................................................54

16.

Turbine Speed Sensor 1 ...........................................................................57

17.

Control Valve Body ...................................................................................58

18.

ATF Filter ..................................................................................................60

19.

Transmission Control Module (TCM) ........................................................61

20.

Lateral G Sensor .......................................................................................62

21.

ATF Cooler Pipe and Hose .......................................................................63

22.

Air Breather Hose......................................................................................68

23.

Oil Charge Pipe.........................................................................................69

24.

Torque Converter Assembly .....................................................................70

25.

Extension Case and Intermediate Case....................................................71

26.

Transfer Clutch..........................................................................................73

27.

Rear Drive Shaft........................................................................................75

28.

Reduction Driven Gear..............................................................................76

29.

Center Differential Carrier .........................................................................78

30.

Parking Pawl .............................................................................................80

31.

Converter Case .........................................................................................82

32.

Oil Pump Cover.........................................................................................84

33.

Drive Pinion Shaft Assembly.....................................................................87

34.

Front Differential Assembly .......................................................................92

35.

AT Main Case ...........................................................................................97

36.

Transmission Control Device ..................................................................107

5AT-2

AUTOMATIC TRANSMISSION

General Description

1. General Description

A: SPECIFICATION

1. TORQUE CONVERTER CLUTCH

2. OIL PUMP

3. TRANSMISSION CONTROL ELEMENT

4. TRANSMISSION GEAR RATIO

5. PLANETARY GEAR AND PLATE

6. SELECTOR POSITION

Model

Turbo

Non-turbo

Type

Symmetric, 3 element, single stage,

2 phase torque converter

Stall torque ratio

2.1

Nominal diameter

250 mm (9.84 in)

Stall speed (at sea 
level)

3,100 — 3,500 

rpm

2,400 — 2,800 

rpm

One-way clutch

Sprague type one-way clutch

Type

Internal gear discharge pump

Driving method

Driven by engine

Number of teeth

Inner rotor

9

Outer rotor

10

Type

5-forward, 1-reverse,

double-row planetary gears

Multi-plate clutch

3 sets

Multi-plate brake

4 sets

One-way clutch 
(sprague type)

3 sets

1st

3.540

2nd

2.264

3rd

1.471

4th

1.000

5th

0.834

Rev

2.370

Model

Turbo

Non-

turbo

Tooth number of front internal gear

106

Tooth number of front carrier

28

Tooth number of front sun gear

50

Tooth number of mid internal gear

78

Tooth number of mid carrier

18

Tooth number of mid sun gear

42

Tooth number of rear internal gear

110

Tooth number of rear carrier

24

Tooth number of rear sun gear

62

Drive plate number of front brake

2

Drive plate number of input clutch

6

5

Drive plate number of high & low 
reverse clutch

4

Drive plate number of direct clutch

5

Drive plate number of reverse brake

5

6

Drive plate number of forward brake

5

4

Drive plate number of low coast brake

3

P (Park)

Transmission in neutral, output mem-
ber immovable, and engine start possi-
ble

R (Reverse)

Transmission in reverse for backing

N (Neutral)

Transmission in neutral and engine 

start possible

D (Drive)

Automatic gear change

1st 

← 

→

 2nd 

←

→

 3rd 

← 

→

 4th 

← 

→

 5th

Manual mode (+)

Manual gear change

1st

→ 2nd→ 3rd→ 4th→ 5th

Manual mode (

−)

Manual gear change

1st

← 2nd← 3rd← 4th← 5th

Control method

Wire cable type