Mitsubishi 380. Manual - part 372

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-28

STANDARD HYDRAULIC PRESSURE TABLE

<F5A5A>

NOTE:  When the torque converter pressure is measured, the engine speed should be 1,500 r/min or less.

HYDRAULIC PRESSURE TEST DIAGNOSIS TABLE

MEASUREMENT 
CONDITIONS

STANDARD HYDRAULIC PRESSURE kPa

SELECT-
OR
LEVER 
POS’N 

SHIFT 
RANGE 
POSITIO
N

ENGINE 
SPEED 
(r/min)

UNDERDRIVE 
CLUTCH 
PRESSURE 
[UD]

REVERSE 
CLUTCH 
PRESSURE 
[RV]

OVERDRIVE 
CLUTCH 
PRESSURE 
[OD]

DIRECT 
CLUTCH 
PRESSURE 
[DIR]

LOW- 
REVERSE 
BRAKE 
PRESSURE 
[LR]

SECOND 
BRAKE 
PRESSURE 
[2ND]

TORQUE 
CONVERTER 
PRESSURE 
[DR]

P

−

2,500

−

−

−

−

260 

− 360

−

260 

− 360 

R

Rev.

2,500

−

1270

−1770  −

−

1270

−1770  −

500 

− 730 

N

−

2,500

−

−

−

−

260 

− 360  −

220 

− 360 

Sport 
mode

1st 2,500

980 

−1050  −

−

−

980 

− 1050  −

500 

− 730 

2nd 2,500

980 

−1050  −

−

−

−

980 

− 1050

500 

− 730 

3rd 2,500

780 

− 900 

−

780 

− 900  −

−

−

450 

− 720 

4th 2,500

780 

− 900 

−

780 

− 900  780 − 880  −

−

450 

− 720 

5th 2,500

−

−

780 

− 900  780 − 880  −

780 

− 880 

450 

− 720 

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

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-29

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

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 direct clutch hydraulic 
pressure is abnormal.

Malfunction of the oil seal R, S or T

Malfunction of the low-reverse solenoid valve(also used for direct clutch)

Malfunction of the low-reverse pressure control valve

Malfunction of the switch valve

Malfunction of the fail safe valve C

Clogged orifice

Incorrect valve body installation

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

SYMPTOM

PROBABLE CAUSE

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-30

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 reduction brake hydraulic 
pressure is abnormal.

Malfunction of the oil seal U or V

Malfunction of the reduction solenoid valve

Malfunction of the reduction pressure control valve

Clogged orifice

Incorrect valve body installation

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 transmission control cable adjustment

Malfunction of the manual valve

Malfunction of the check ball

Incorrect valve body installation

SYMPTOM

PROBABLE CAUSE

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-31

OIL SEAL LAYOUT

10DB149A

A

B

C

D

E F

G

H

I

J

K L

M N

O

P Q   R

S

T