Mitsubishi Montero (2002-2004). Manual — part 978

SYMPTOM PROCEDURES <AUTOMATIC TRANSMISSION>

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SYMPTOM PROCEDURES

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STEP 6. 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 8.

STEP 7. Replace each solenoid valve.
Replace the faulty solenoid valve with a new one.
Q: Is the symptom eliminated?

YES : The procedure is complete.
NO : Go to Step 8.

STEP 8. Replace the PCM.
Q: Is the symptom eliminated?

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

INSPECTION PROCEDURE 11: Early or Late Shifting Some Gears

.

COMMENT
If some of the shift points are early or late when driv-
ing, the cause is probably a malfunction of the valve
body, or it is due to the characteristics of the
INVECS-II system but is not an abnormality.

.

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

• Malfunction of the valve body

• Malfunction of the PCM

ACX02161AD

VALVE BODY ASSEMBLY

ACX02161AF

LOW-REVERSE
SOLENOID
VALVE

TORQUE CONVERTER
CLUTCH SOLENOID VALVE

OVER DRIVE
SOLENOID VALVE

SECOND
SOLENOID
VALVE

UNDERDRIVE
SOLENOID VALVE

REDUCTION
SOLENOID
VALVE <5A/T>

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
item 14: INVECS-II Cancel Command.

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 actuator test mode for item14,

INVECS-II Cancel Command.

• Drive the vehicle and confirm the gear shifting corre-

spond to the standard shift line of the shift pattern dia-
gram. Refer to

P.23Aa-3

.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Does the gear shifting correspond to the standard shift

line of the shift pattern diagram?
YES : The symptom is due to characteristics of the INVECS-

II system, but is not abnormal.

NO : Go to Step 2.

STEP 2. Check the shift points.
Q: Are the shift points early or late only when transmission

fluid is -29

°C (84°F) or less (early), or 125°C (257°F) or

more (late)?
YES : The symptom is due to characteristics of the INVECS-

II system, but is not abnormal.

NO : Go to Step 3.

STEP 3. 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 4.

STEP 4. Replace the PCM.
Q: Is the symptom eliminated?

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

ACX01539AD

MB991502

16-PIN

ACX02161AD

VALVE BODY ASSEMBLY

SYMPTOM PROCEDURES <AUTOMATIC TRANSMISSION>

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SYMPTOM PROCEDURES

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INSPECTION PROCEDURE 12: No Diagnostic Trouble Codes (Does not Shift)

.

CIRCUIT OPERATION
PCM (terminal 58) receives battery positive voltage
from the battery.

.

AC205198 AB

Backup Power Supply Circuit

AC204167

CONNECTOR : A-03

AT

A-03 (B)

6

12

5

3 4

2

1

9 10

8

7

11

AC204681AD

CONNECTOR: D-133

D-133 (GR)

31 32

33 34

35 36 37 38 39 40 41 42 43
44 45 46 47 48 49

50 51

52 53

54 55 56

57 58

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SYMPTOM PROCEDURES

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COMMENT
If shifting does not occur while driving and no diag-
nostic trouble codes are set, a malfunction of the
transmission range switch, or PCM may exist.

.

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

• Malfunction of transmission range switch

• Damaged harness, connector

• Malfunction of the PCM

DIAGNOSIS

Required Special Tool:

• MB991502: Scan Tool (MUT-II)

STEP 1. Check the vehicle acceleration.
Q: Does the vehicle accelerate poorly (transmission stays

in 3rd gear) when starting from a stop with the selector
lever in "D" range?
YES : Go to Step 2.
NO : Go to Step 5.

STEP 2. Measure the backup power supply voltage at PCM
connector D-133 by backprobing.
(1) Do not disconnect connector D-133.

(2) Measure the voltage between terminal 58 and ground by

backprobing.

• The voltage should measure battery positive voltage.

Q: Is the measured voltage battery positive voltage?

YES : Go to Step 5.
NO : Go to Step 3.

AC204681AD

CONNECTOR: D-133

D-133 (GR)

31 32

33 34

35 36 37 38 39 40 41 42 43
44 45 46 47 48 49

50 51

52 53

54 55 56

57 58

AC204918 DM

D-133 HARNESS CONNECTOR :
HARNESS SIDE

50

58

43

36 37

35
44
52

45

53

32

31

42

38 39 40 41

46

55

48

54

51

47

49
56

33 34

57