Mitsubishi Montero (2004+). Manual - part 939

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-331

.

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

.

COMMENT
If shifting does not occur while driving and no diag-
nostic trouble codes are output, 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:

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

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B

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.

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

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-332

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

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-333

STEP 3. Check intermediate connector A-03 and PCM 
connector D-133 for loose, corroded or damaged 
terminals, or terminals pushed back in the connector.
Q: Are the connectors and terminals in good condition?

YES : Go to Step 4.
NO :  Repair or replace the damaged components. Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-2

. Then retest the system.

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

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-334

STEP 4. Check the harness for open circuit between PCM 
connector D-133 terminal 58 and fusible link.
Q: Is the harness wire in good condition?

YES : Go to Step 5.
NO :  Repair or replace the harness wire.

STEP 5. Using scan tool MB991958, check data list item 61: 
Transmission Range 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 61: Transmission Range Switch.

• Move the selector lever to "P," "R," "N," "D" and sport 

mode positions and confirm that the selected trans-
mission ranges match the positions shown on scan 
tool MB991958 (Sport mode is indicated as "D" on 
scan tool MB991958).

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

YES : Check for the symptom. If the symptom is not 

eliminated, replace the PCM.

NO :  Refer to 

P.23A-121

, 

P.23A-150

, DTCs 27, 28: 

Transmission Range Switch System.

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

AC307591 AC

MB991911

MB991824

MB991827

AC307591

DATA LINK

CONNECTOR