Mitsubishi Montero (2004+). Manual — part 950

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-375

.

CIRCUIT OPERATION

• A battery positive voltage is applied to the 4LLc

detection switch output terminal (terminal 1) from
the PCM (terminal 55) via the resistance in the
unit.

• The 4LLc detection switch is grounded through

the transfer case to the vehicle body.

.

COMMENT
If the transmission will not shift to 4th gear, or if it
shifts to 4th gear when the transfer lever is in the
"4LLc" position, the cause is probably a malfunction
of the 4LLc detection switch.

.

TROUBLESHOOTING HINTS (THE MOST LIKELY
CAUSES FOR THIS CASE:)

• Malfunction of the 4LLc detection switch

• Damaged harness, connector

• Malfunction of the PCM

DIAGNOSIS

Required Special Tool:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B

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

AC204176

CONNECTOR : E-114

BD

38

28

16

33

22

10

31

19

7

1

18

30

29

17

5

6

21

20

32

8

2

9

25

13

3

24

23

3435

1112

27

26

3637

14

4

15

AUTOMATIC TRANSMISSION DIAGNOSIS

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AUTOMATIC TRANSMISSION

23A-376

STEP 1. Using scan tool MB991958, check data list item 75:
4LLc Detection Switch.

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991958 to the data reading mode.

• Item 75: 4LLc Detection Switch.

• When the transfer shift lever position is 4LLc, scan

tool MB991958 display should be "ON."

• When the transfer shift lever position is other than

4LLc, scan tool MB991958 display should be "OFF."

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

YES : It can be assumed that this malfunction is intermittent.

Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

− How to

Cope with Intermittent Malfunction

P.00-6

.

NO : Go to Step 2.

STEP 2. Check 4LLc detection switch connector C-05 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Are the connector and terminals in good condition?

YES : Go to Step 3.
NO : Repair or replace the damaged components. Refer to

GROUP 00E, Harness Connector Inspection

P.00E-2

.

AC307591 AC

MB991911

MB991824

MB991827

AC307591

DATA LINK

CONNECTOR

AC204395

CONNECTOR : C-05

AG

C-05 (BR)

C-05

1

AUTOMATIC TRANSMISSION DIAGNOSIS

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AUTOMATIC TRANSMISSION

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STEP 3. Measure the switch output voltage at 4LLc
detection switch connector C-05.
(1) Disconnect connector C-05 and measure at the harness

side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal 1 and ground.

• The voltage should measure battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage battery positive voltage?

YES : Go to Step 10.
NO : Go to Step 4.

AC204395

CONNECTOR : C-05

AG

C-05 (BR)

C-05

1

AC204918 AO

C-05 HARNESS CONNECTOR :
COMPONENT SIDE

1

AUTOMATIC TRANSMISSION DIAGNOSIS

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AUTOMATIC TRANSMISSION

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STEP 4. Measure the switch output voltage at PCM
connector D-133 by backprobing.
(1) Do not disconnect connector D-133.
(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal 55 and ground by

backprobing.

• The voltage should measure battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage battery positive voltage?

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

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 BD

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