Mitsubishi Montero Sport (2004+). Manual - part 701

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-369

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

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

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

.

CIRCUIT OPERATION
PCM (terminal number 66) 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

Backup Power Supply Circuit

PCM

60

46

66

57

45

44

64

55 56

65

62 63

52 53

5051

61

42

59

48

41
47
58

43
49

54

AC202313

C-90 (GR)

AB

CONNECTOR: C-90

C-90 (GR)

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-370

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.

STEP 2. Measure the backup power supply voltage at PCM 
connector C-90 by backprobing.

(1) Do not disconnect connector C-90.

(2) Measure the voltage between terminal 66 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.

PCM

60

46

66

57

45

44

64

55 56

65

62 63

52 53

5051

61

42

59

48

41
47
58

43
49

54

AC202313

C-90 (GR)

AB

CONNECTOR: C-90

C-90 (GR)

AC002091

C-90 HARNESS CONNECTOR:
HARNESS SIDE 

AJ

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-371

STEP 3. Check PCM connector C-90 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 4.
NO :  Repair or replace the damaged components. Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-2

. Then check for the symptom.

STEP 4. Check the harness for open circuit between PCM 
connector C-90 terminal 66 and fusible link.

Q: Is the harness wire in good condition?

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

PCM

60

46

66

57

45

44

64

55 56

65

62 63

52 53

5051

61

42

59

48

41
47
58

43
49

54

AC202313

C-90 (GR)

AB

CONNECTOR: C-90

C-90 (GR)

PCM

60

46

66

57

45

44

64

55 56

65

62 63

52 53

5051

61

42

59

48

41
47
58

43
49

54

AC202313

C-90 (GR)

AB

CONNECTOR: C-90

C-90 (GR)

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-372

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 data reading mode.

• Item 61: Transmission Range Switch.

• Move the selector lever to "P," "R," "N," "D," "3," "2," 

"L" positions and confirm that the selected transmis-
sion ranges match the positions shown 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-123

, 

P.23A-181

, DTCs 27, 28: 

Transmission range switch system.

INSPECTION PROCEDURE 13: Poor Acceleration

.

COMMENT
If acceleration is poor when downshifting occurs 
while driving, a malfunction of the engine system or a 
brake or clutch may exist.

.

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

• Malfunction of the engine system

• Malfunction of the clutch system and brake sys-

tem

• Malfunction of the PCM

DIAGNOSIS

STEP 1. Check the engine system.

Refer to GROUP 13A, Diagnosis 

− Symptom Chart − Poor 

Acceleration 

P.13A-778

.

Q: Is the inspection result good?

YES : Go to Step 2.
NO :  Repair or replace the engine component(s).

AK303629AB

MB991911

MB991827

MB991824 

16-PIN