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