Mitsubishi Montero (2002-2004). Manual — part 977

SYMPTOM PROCEDURES <AUTOMATIC TRANSMISSION>

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SYMPTOM PROCEDURES

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DIAGNOSIS

Required Special Tool:

• MB991502: Scan Tool (MUT-II)

STEP 1. Using scan tool MB991502, check actuator test.

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991502.
(1) Connect scan tool MB991502 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991502 to actuator test mode for following

items.

a. Item 01: Low-reverse solenoid valve
b. Item 02: Underdrive solenoid valve

c. Item 03: Second solenoid valve

d. Item 04: Overdrive solenoid valve
e. Item 05: Reduction solenoid valve

• An audible clicking or buzzing should be heard when

the solenoid valves are energized.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Are the solenoid valves operating properly?

YES : Go to Step 2.
NO : Repair or replace the solenoid valves. Refer to

GROUP 23B, Valve Body

P.23B-80

. Then confirm

that the symptom is eliminated.

STEP 2. Check the hydraulic pressure.
(1) Measure the hydraulic pressure of each element. Check if

each hydraulic pressure is within the standard value. Refer
to

P.23Ab-15

, Hydraulic Pressure Test.

(2) If some elements are within the standard value and some

are not, recheck the symptom.

Q: Are all hydraulic pressures within the standard value?

YES : Go to Step 6.
NO : Go to Step 3.

STEP 3. Adjust the line pressure.
Adjust the line pressure. Refer to

P.23Ab-31

, Line Pressure

Adjustment. Then check the symptom.
Q: Is the symptom eliminated?

YES : The procedure is complete.
NO : Go to Step 4.

ACX01539AD

MB991502

16-PIN

SYMPTOM PROCEDURES <AUTOMATIC TRANSMISSION>

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SYMPTOM PROCEDURES

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STEP 4. Replace the oil pump.
(1) Remove the transmission.
(2) Replace the oil pump. (Oil pump can not be repaired). Refer

to GROUP 23B, Transmission

P.23B-18

. Then check the

symptom.

Q: Is the symptom eliminated?

YES : The procedure is complete.
NO : Go to Step 5.

STEP 5. Disassemble and clean the valve body.
Check the O-ring installation bolts for looseness and the valve
body for damage. Repair or replace the faulty parts. Refer to
GROUP 23B, Valve Body

P.23B-80

.

Replace the valve body assembly if the damages are thought
to be irreparable. Then check the symptom.
Q: Is the symptom eliminated?

YES : The procedure is complete.
NO : Go to Step 7.

STEP 6. Check each brake and clutch.
(1) Remove the transmission.
(2) Check the facing for seizure and piston seal ring for

damage and interference with retainer. Repair or replace
the faulty parts. Refer to GROUP 23B, Transmission

P.23B-

18

, Underdrive Clutch

P.23B-76

, Reverse and Overdrive

Clutches

P.23B-67

, Direct Clutch

P.23B-91

. Then check for

the symptom.

Q: Is the symptom eliminated?

YES : The procedure is complete.
NO : Go to Step 7.

STEP 7. Replace the PCM.
Q: Is the symptom eliminated?

YES : The procedure is complete.
NO : Start over at Step 1.

AC204883 AD

ACX02161AD

VALVE BODY ASSEMBLY

AC204883 AH

OVERDRIVE
CLUTCH

REDUCTION
BRAKE

REVERSE
CLUTCH

SECOND
BRAKE

LOW-REVERSE
BRAKE

UNDERDRIVE
CLUTCH

DIRECT
CLUTCH

SYMPTOM PROCEDURES <AUTOMATIC TRANSMISSION>

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SYMPTOM PROCEDURES

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INSPECTION PROCEDURE 10: Early or Late Shifting All Gears

.

COMMENT
If all shift points are early or late while driving, the
cause is probably a malfunction of the output shaft
speed sensor, APP sensor or a solenoid valve.

.

TROUBLESHOOTING HINTS (The most likely
causes for this case:)

• Malfunction of the output shaft speed sensor

• Malfunction of the APP sensor

• Malfunction of each solenoid valve

• Abnormal line pressure

• Malfunction of the valve body

• Malfunction of the PCM

DIAGNOSIS

Required Special Tool:

• MB991502: Scan Tool (MUT-II)

STEP 1. Using scan tool MB991502, check data list item 23:
Output Shaft Speed Sensor.

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991502.
(1) Connect scan tool MB991502 to the data link connector.
(2) Start the engine.
(3) Set scan tool MB991502 to data reading mode for item 23,

Output Shaft Speed Sensor.

• When driving at constant speed of 50 km/h (31 mph),

the display should be "1,400

− 1,700 r/min". (Gear

range: 4th gear)

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : Go to Step 2.
NO : Refer to

P.23Ac-65

, DTC 23: Output shaft speed

sensor system.

STEP 2. Using scan tool MB991502, check data list item 11:
TP Sensor.
(1) Connect scan tool MB991502 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991502 to data reading mode for item 11,

TP Sensor.

• With the throttle valve in the idle position, voltage should

measure between 200 and 800 mV.

• With the throttle valve in the full-open position, voltage

should measure between 3,800 and 4,900 mV.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 200 and 800 mV at

idle, and between 3,800 and 4,900 mV in the full-open
position?
YES : Go to Step 4.
NO : Go to Step 3.

ACX01539AD

MB991502

16-PIN

ACX01539AD

MB991502

16-PIN

SYMPTOM PROCEDURES <AUTOMATIC TRANSMISSION>

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SYMPTOM PROCEDURES

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STEP 3. Using scan tool MB991502, read the MFI
diagnostic trouble code.
(1) Connect scan tool MB991502 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check for MFI diagnostic trouble code.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Are MFI DTC Nos. of TP sensor system set?

YES : Refer to GROUP 13A, Diagnosis

− Diagnostic

Trouble Code Chart

P.13Ab-22

.

NO : Go to Step 8.

STEP 4. Using scan tool MB991502, check data list.
(1) Connect scan tool MB991502 to the data link connector.
(2) Start the engine.
(3) Set scan tool MB991502 to data reading mode for following

items.

a. Item 31: Low-Reverse Solenoid Valve Duty Percent
b. Item 32: Underdrive Solenoid Valve Duty Percent

c. Item 33: Second Solenoid Valve Duty Percent

d. Item 34: Overdrive Solenoid Valve Duty Percent
e. Item 35: Reduction Solenoid Valve Duty Percent

• Check that the values shown below are displayed

when each data list item is entered.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Are the solenoid valves operating properly?

YES : Go to Step 5.
NO : Go to Step 7.

STEP 5. Adjust the line pressure.
Adjust the line pressure. Refer to

P.23Ab-31

, Line Pressure

Adjustment. Then check the symptom.
Q: Is the symptom eliminated?

YES : The procedure is complete.
NO : Go to Step 6.

ACX01539AD

MB991502

16-PIN

DRIVING CONDITION

DATA LIST ITEM
31

32

33

34

35

Driving at constant speed of 10 km/h (6.2
mph) in 1st gear

0%

0%

100%

100%

0%

Driving at constant speed of 30 km/h (19
mph) in 2nd gear

100%

0%

0%

100%

0%

Driving at constant speed of 50 km/h (31
mph) in 3rd gear

100%

0%

100%

0%

0%

Driving at constant speed of 50 km/h (31
mph) in 4th gear

0%

0%

100%

0%

100%

Driving at constant speed of 70 km/h (44
mph) in 5th gear

100%

100%

0%

0%

100%

ACX01539AD

MB991502

16-PIN