Mitsubishi Galant (2004+). Manual - part 620

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-31

HYDRAULIC PRESSURE TEST DIAGNOSIS TABLE

SYMPTOM

PROBABLE CAUSE

All hydraulic pressures are high. Malfunction of the regulator valve
All hydraulic pressures are low.

Malfunction of the oil pump
Clogged internal oil filter
Clogged oil cooler
Malfunction of the regulator valve
Malfunction of the relief valve
Incorrect valve body installation
Improperly installed solenoid valves
Damaged solenoid valve O-rings

Hydraulic pressure is abnormal 
in reverse gear only.

Malfunction of the regulator valve
Clogged orifice
Incorrect valve body installation

Hydraulic pressure is abnormal 
in 3rd or 4th gear only.

Malfunction of the overdrive solenoid valve
Malfunction of the overdrive pressure control valve
Malfunction of the regulator valve
Malfunction of the switch valve
Clogged orifice
Incorrect valve body installation

Only underdrive clutch hydraulic 
pressure is abnormal.

Malfunction of the oil seal K
Malfunction of the oil seal L
Malfunction of the oil seal M
Malfunction of the underdrive solenoid valve
Malfunction of the underdrive pressure control valve
Malfunction of the check ball
Clogged orifice
Incorrect valve body installation
Malfunction of the accumulator for underdrive clutch

Only reverse clutch hydraulic 
pressure is abnormal.

Malfunction of the oil seal A
Malfunction of the oil seal B
Malfunction of the oil seal C
Clogged orifice
Incorrect valve body installation

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-32

Only overdrive clutch hydraulic 
pressure is abnormal.

Malfunction of the oil seal D
Malfunction of the oil seal E
Malfunction of the oil seal F
Malfunction of the overdrive solenoid valve
Malfunction of the overdrive pressure control valve
Malfunction of the check ball
Clogged orifice
Incorrect valve body installation
Malfunction of the accumulator for overdrive clutch

Only low-reverse brake 
hydraulic pressure is abnormal.

Malfunction of the oil seal I
Malfunction of the oil seal J
Malfunction of the low-reverse solenoid valve
Malfunction of the low-reverse pressure control valve
Malfunction of the switch valve
Malfunction of the fail safe valve A
Malfunction of all the check balls
Clogged orifice
Incorrect valve body installation
Malfunction of the accumulator for low-reverse brake

Only second brake hydraulic 
pressure is abnormal.

Malfunction of the oil seal G
Malfunction of the oil seal H
Malfunction of the oil seal O
Malfunction of the second solenoid valve
Malfunction of the second pressure control valve
Malfunction of the fail safe valve B
Clogged orifice
Incorrect valve body installation
Malfunction of the accumulator for second brake

Only torque converter pressure 
is abnormal.

Clogged oil cooler
Malfunction of the oil seal N
Malfunction of the torque converter clutch solenoid
Malfunction of the torque converter pressure control valve
Clogged orifice
Incorrect valve body installation

Pressure applied to element 
which should not receive 
pressure.

Incorrect transaxle control cable adjustment
Malfunction of the manual valve
Malfunction of the check ball
Incorrect valve body installation

SYMPTOM

PROBABLE CAUSE

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-33

OIL SEAL LAYOUT

AC006152

A

B

C

D

E

F G

H

I

J K

L

M

N

O

AB

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-34

HYDRAULIC CIRCUIT

M1231008800336

PARKING AND NEUTRAL

AC308907

AC308907

: LINE PRESSURE

: OIL PUMP SUCTION PRESSURE

: TORQUE CONVERTER CLUTCH
  PRESSURE

: TORQUE CONVERTER AND LUBRICATION
  PRESSURE

: TORQUE CONVERTER CLUTCH SOLENOID
  VALVE PRESSURE

AB

1

2

3

4

5

6

6

6

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

31

30

29

P

RN D

3

2

L

  1. REVERSE 

CLUTCH

  2. LOW-REVERSE 

BRAKE

  3. SECOND 

BRAKE

  4. UNDERDRIVE 

CLUTCH

  5. OVERDRIVE 

CLUTCH

  6. ACCUMULATOR
  7. CHECK 

BALL

  8. TORQUE 

CONVERTER 

CLUTCH

  9. FAIL 

SAFE 

VALVE 

A

  10. 

FAIL 

SAFE 

VALVE 

B

    11.  TORQUE CONVERTER CLUTCH CONTROL 

VALVE

  12. 

SWITCH 

VALVE

  13. 

TRANSMISSION 

FLUID 

COOLER

  14. 

LUBRICATION

    15.  LOW-REVERSE PRESSURE CONTROL VALVE
  16. 

SECOND 

PRESSURE 

CONTROL 

VALVE

    17.  UNDERDRIVE PRESSURE CONTROL VALVE
    18.  OVERDRIVE PRESSURE CONTROL VALVE
    19.  TORQUE CONVERTER CLUTCH SOLENOID 

VALVE

  20. 

LOW-REVERSE 

SOLENOID 

VALVE

    21.  SECOND SOLENOID VALVE
    22.  UNDERDRIVE SOLENOID VALVE
  23. 

OVERDRIVE 

SOLENOID 

VALVE

    24.  TORQUE CONVERTER PRESSURE 

CONTROL VALVE

  25. 

REGULATOR 

VALVE

  26. 

MANUAL 

VALVE

  27. 

OIL 

FILTER

  28. 

OIL 

PUMP

  29. 

OIL 

STRAINER

  30. 

RELIEF 

VALVE

  31. 

OIL 

PAN