Mitsubishi Galant. Manual — part 389

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-23

TORQUE CONVERTER STALL TEST JUDGEMENT
RESULTS

1. Stall speed is too high in both "D" range only

•

Low line pressure

•

Low-reverse brake slippage and malfunction of one-way
clutch

2. Stall speed is too high in "D" range only

•

Underdrive clutch slippage

3. Stall speed is too high in "R" range only

•

Reverse clutch slippage

4. Stall speed too low in both "D" and "R" ranges

•

Malfunction of torque converter

•

Insufficient engine output

HYDRAULIC PRESSURE TESTS

M1231005500057

1. Check the A/T fluid level and temperature. Check engine

coolant temperature.

•

A/T fluid level: "HOT" mark on the dipstick

•

A/T fluid temperature: 70 - 80

°

C (158 - 176

°

F)

•

Engine coolant temperature: 80 - 100

°

C (176 - 212

°

F)

2. Jack up the vehicle so that the wheels are free to turn.

AUTOMATIC TRANSAXLE DIAGNOSIS

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AUTOMATIC TRANSAXLE

23A-24

3. Connect the special tools (2,942 kPa (427 psi) oil pressure

gauge [MD998330] and adapters [MD998332, MD998900])
to each pressure discharge port.

NOTE:

.

•

2ND: Second brake pressure port

•

UD: Underdrive clutch pressure port

•

LR: Low-reverse brake pressure port

•

DA: Torque converter apply pressure port

•

DR: Torque converter release pressure port

•

RV: Reverse clutch pressure port

•

OD: Overdrive clutch pressure port

4. Measure the hydraulic pressure at each port under the

conditions given in the standard hydraulic pressure table,
and check that the measured values are within the standard
value ranges.

5. If a value is outside the standard range, correct the problem

while referring to the hydraulic pressure test diagnosis table.

STANDARD HYDRAULIC PRESSURE TEST

AC001827

AC001825

AC001828

MEASUREMENT CONDI-
TION

STANDARD HYDRAULIC PRESSURE kPa (psi)

SELEC-
TOR
LEVER
POSI-
TION

SHIFT
POSI-
TION

ENGINE
SPEED
(r/min)

UNDER-
DRIVE
CLUTCH
PRES-
SURE
[UD]

REVERSE
CLUTCH
PRES-
SURE [RV]

OVER-
DRIVE
CLUTCH
PRES-
SURE
[OD]

LOW-
REVERSE
BRAKE
PRES-
SURE [LR]

SECOND
BRAKE
PRES-
SURE
[2ND]

TORQUE
CON-
VERTER
PRES-
SURE
[DR]

P

−

2,500

−

−

−

220

−

360

(32

−

52)

−

250

−

390

(37

−

57)

R

Reverse

2,500

−

1,270

−

1,770
(185

−

256)

−

1,270

−

1,770
(185

−

256)

−

500

−

700

(73

−

101)

N

−

2,500

−

−

−

220

−

360

(32

−

52)

−

250

−

390

(37

−

57)

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-25

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

HYDRAULIC PRESSURE TEST DIAGNOSIS TABLE

L

1st gear

2,500

1,010

−

1,050
(147

−

152)

−

−

−

1,010

−

1,050
(147

−

152)

500

−

700

(73

−

101)

2

2nd gear 2,500

1,010

−

1,050
(147

−

152)

−

−

−

1,010

−

1,050
(147

−

152)

500

−

700

(73

−

101)

3

3rd gear

2,500

784

−

882

(113

−

128)

−

784

−

882

(113

−

128)

−

−

−

D

4th gear

2,500

−

−

784

−

882

(113

−

128)

−

784

−

882

(113

−

128)

−

MEASUREMENT CONDI-
TION

STANDARD HYDRAULIC PRESSURE kPa (psi)

SELEC-
TOR
LEVER
POSI-
TION

SHIFT
POSI-
TION

ENGINE
SPEED
(r/min)

UNDER-
DRIVE
CLUTCH
PRES-
SURE
[UD]

REVERSE
CLUTCH
PRES-
SURE [RV]

OVER-
DRIVE
CLUTCH
PRES-
SURE
[OD]

LOW-
REVERSE
BRAKE
PRES-
SURE [LR]

SECOND
BRAKE
PRES-
SURE
[2ND]

TORQUE
CON-
VERTER
PRES-
SURE
[DR]

SYMPTOMS

PROBABLE CAUSE

All hydraulic pressures are high. Incorrect transaxle control cable adjustment

Malfunction of the regulator valve

All hydraulic pressures are low.

Incorrect transaxle control cable adjustment

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

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 TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-26

Only underdrive hydraulic pres-
sure 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 check ball

Clogged orifice

Incorrect valve body installation

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 hydraulic pres-
sure 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 check ball

Clogged orifice

Incorrect valve body installation

Only low-reverse hydraulic pres-
sure 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 check ball

Clogged orifice

Incorrect valve body installation

Only second 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

SYMPTOMS

PROBABLE CAUSE