Mitsubishi Montero (2002-2004). Manual - part 868

AUTOMATIC TRANSMISSION DIAGNOSIS

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AUTOMATIC TRANSMISSION DIAGNOSIS

23Ab-13

8

Use scan tool 
MB991502 to 
stop the 
INVECS-II 
function.
Transmission 
range: D (on a 
flat and straight 
road.)

(1) Select to the 
sport mode while 
driving at 60 km/
h (37 mph) in 5th 
gear, shift down 
to 4th gear.
(2) While driving 
at 40 km/h (37 
mph) in 4th gear, 
down shift to 3 
range.
(3) While driving 
at 20 km/h (25 
mph) in 3rd gear, 
down shift to 2nd 
gear.
(4) While driving 
at 20 km/h (12 
mph) in 2nd 
gear, down shift 
to 1st gear.

Data list No.63
(1) 5th 

→ 4th

(2) 4th 

→ 3rd

(3) 3rd 

→ 2nd

(4) 2nd 

→ 1st

Does not shift 
from 4 to 5 or 5 
to 4

32

Underdrive 
solenoid valve 
system 
(

P.23Ac-160

)

33

Second 
solenoid valve 
system 
(

P.23Ac-171

)

44

4th gear 
incorrect ratio 
(

P.23Ac-215

)

45

5th gear 
incorrect ratio 
(

P.23Ac-215

)

9

Transmission 
range: N (on a 
flat and straight 
road.)

Monitor data list 
No. 22 and No. 
23 with scan tool 
MB991502.
(1)Move selector 
lever to R range, 
drive at constant 
speed of 10 km/h 
(6.2 mph).

The ratio between 
data list No. 22 
and No. 23 should 
be the same as the 
gear ratio when 
reversing.

Does not 
match

22

Input shaft 
speed sensor 
system 
(

P.23Ac-47

)

23

Output shaft 
speed sensor 
system 
(

P.23Ac-65

)

46

Reverse gear 
incorrect ratio 
(

P.23Ac-215

)

STEP CONDITION 

BEFORE TEST/
OPERATION

TEST/
OPERATION

STANDARD

INSPECTION 
ITEM

DTC

INSPECTION 
PROCEDURE 
PAGE

AUTOMATIC TRANSMISSION DIAGNOSIS

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AUTOMATIC TRANSMISSION DIAGNOSIS

23Ab-14

TORQUE CONVERTER STALL TEST

M1231103500100

This test measures the maximum engine speed when the 
selector lever is in the "D" or "R" position and the torque con-
verter stalls. This tests the operation of the torque converter 
(stator and one-way clutch operation) as well as the holding 
performance of the clutches and brakes in the transmission.

WARNING

Do not let anyone stand in front of or behind the vehi-
cle while this test is performed.

1. Check the transmission fluid level and temperature. Check 

the engine coolant temperature.

• Transmission fluid level: At the "HOT" mark on the dipstick

• Transmission fluid temperature: 70 − 80 °C (158 − 176 °F)

• Engine coolant temperature: 80 − 100 °C (176 − 212 °F)

NOTE: Measures transmission fluid temperature with scan 
tool MB991502 (MUT-II).

2. Chock both front wheels.
3. Connect a tachometer.
4. Apply the parking and service brakes fully.
5. Start the engine.
6. Move the selector lever to the "D" position. Fully depress the 

accelerator pedal and read the maximum engine speed.

CAUTION

• The throttle should not be fully open for any more than 

five seconds.

• If you repeat the stall test when the transmission fluid 

temperature is greater than 80

°C (176°F) move the 

selector lever to the "N" position and let the engine run 
at approximately 1,000 r/min for at least one minute. 
Wait until the transmission fluid temperature returns to 
80

°C (176°F) or less.

Standard value: Stall speed: 2,200 

− 2,700 r/min

7. Move the selector lever to the "R" position. Fully depress the 

accelerator pedal and read the maximum engine speed.

Standard value: Stall speed: 2,200 

− 2,700 r/min

TORQUE CONVERTER STALL TEST JUDGMENT 
RESULTS

1. Stall speed is too high in both "D" and "R" ranges

• Malfunction of the torque converter (Slippage on the splines 

of the torque converter and the input shaft)

• Low line pressure

• Low-reverse brake slippage and malfunction of the 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

• Low-reverse brake slippage

• Reduction brake slippage

AC204712 AB

LOW-REVERSE 
BRAKE

ONE WAY CLUTCH

REVERSE 
CLUTCH

UNDERDRIVE 
CLUTCH

REDUCTION
BRAKE

TORQUE 
CONVERTER

AUTOMATIC TRANSMISSION DIAGNOSIS

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AUTOMATIC TRANSMISSION DIAGNOSIS

23Ab-15

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

• Malfunction of the torque converter (Slippage of the one-

way clutch)

• Insufficient engine output

HYDRAULIC PRESSURE TESTS

M1231103800101

1. Check the transmission fluid level and temperature. Check 

engine coolant temperature.

• Transmission fluid level: "HOT" mark on the dipstick

• Transmission fluid temperature: 70 − 80°C (158 − 176°F)

• Engine coolant temperature: 80 − 100°C (176 − 212°F)

CAUTION

The transmission fluid temperature should be between 70 
− 80 °C (158 − 176°F) during the test.
2. Raise the vehicle so that the wheels are free to turn.
3. Connect the special tools (3.0 MPa (427 psi) oil pressure 

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

.

•

UC: Underdrive clutch pressure port

•

RC: Reverse clutch pressure port

•

OC: Overdrive clutch pressure port

•

DC: Direct clutch pressure port

•

LB: Low-reverse brake pressure port

•

2B: Second brake pressure port

•

RB: Reduction brake pressure port

•

TA: Torque converter apply pressure port

•

TR: Torque converter release pressure port

4. Restart the engine.
5. Check that there are no leaks around the special tool port 

adaptors.

6. 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.

7. If the pressure is not within the standard value, stop the 

engine and refer to the hydraulic pressure test diagnosis 
table.

8. Remove the O-ring from the port plug and replace it.
9. Remove the special tool, and install the plugs to the 

hydraulic pressure ports.

10.Start the engine and check that there are no leaks around 

the plugs.

AC101188AB

MD998900

MD998330

OIL PAN

AC101189AB

MD998900

MD998330

TRANSMISSION CONTROL 
CABLE

AC101190AC

MD998332

MD998330

OIL COOLER TUBE CONNECTION

AUTOMATIC TRANSMISSION DIAGNOSIS

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AUTOMATIC TRANSMISSION DIAGNOSIS

23Ab-16

STANDARD HYDRAULIC PRESSURE TEST

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

MEASUREMENT 
CONDITION

STANDARD HYDRAULIC PRESSURE MPa (psi)

TRANS-
MISSION 
RANGE

SHIFT 
POSITION

ENGINE 
SPEED 
(r/min)

UNDERDRIVE 
CLUTCH 
PRESSURE 
[UC]

REVERSE 
CLUTCH 
PRESSURE 
[RC]

OVERDRIVE 
CLUTCH 
PRESSURE 
[OC]

DIRECT 
CLUTCH 
PRESSURE 
[DC]

LOW- 
REVERSE 
BRAKE 
PRESSURE 
[LB]

SECOND 
BRAKE 
PRESSURE 
[2B]

REDUC-
TION 
BRAKE 
PRESSURE 
[RB]

TORQUE 
CONVER-
TER 
CLUTCH 
PRESSURE 
[TR]

P

−

2,500

−

−

−

−

0.26 

− 

0.34 
(38 

− 

49)

−

1.01 

− 

1.05 
(147 

− 

152)

0.22 

− 

0.36 (32 
− 52)

R

Reverse

2,500

−

1.27 

− 

1.77 
(185 

− 

256)

−

−

1.27 

− 

1.77 
(185 

− 

256)

−

1.27 

− 

1.77 
(185 

− 

256)

0.65 

− 

0.85 (94 
− 123)

N

−

2,500

−

−

−

−

0.26 

− 

0.34 
(38 

− 

49)

−

0.26 

− 

0.34 
(38 

− 

49)

0.22 

− 

0.36 (32 
− 52)

Sport 
mode

1st 
gear

2,500

1.01 

− 

1.05 (147 
− 152)

−

−

−

1.01 

− 

1.05 
(147 

− 

152)

−

1.01 

− 

1.05 
(147 

− 

152)

0.65 

− 

0.85 (94 
− 123)

2nd 
gear

2,500

1.01 

− 

1.05 (147 
− 152)

−

−

−

−

1.01 

− 

1.05 (147 
− 152)

1.01 

− 

1.05 
(147 

− 

152)

0.65 

− 

0.85 (94 
− 123)

3rd 
gear

2,500

0.78 

− 

0.88 (113 
− 28)

−

0.78 

− 

0.88 (113 
− 128)

−

−

−

0.78 

− 

0.88 
(113 

− 

128)

0.65 

− 

0.85 (94 
− 123)

4th 
gear

2,500

0.78 

− 

0.88 (113 
− 28)

−

0.78 

− 

0.88 (113 
− 128)

0.78 

− 

0.88 (113 
− 128)

−

−

−

−

5th 
gear

2,500

−

−

0.78 

− 

0.88 (113 
− 128)

0.78 

− 

0.88 (113 
− 128)

−

0.78 

− 

0.88 (113 
− 128)

−

−