Mitsubishi Montero (2002-2004). Manual - part 983

SYMPTOM PROCEDURES <AUTOMATIC TRANSMISSION>

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SYMPTOM PROCEDURES

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STEP 11. Check intermediate connector A-03 and PCM 
connector D-134 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 12.
NO :  Repair or replace the damaged components. Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-

2

.

AC204167

CONNECTOR : A-03

AT

A-03 (B)

6

12

5

3 4

2

1

9 10

8

7

11

AC204681AC

CONNECTOR: D-134

D-134 (GR)

61 62

63 64

65 66 67 68 69 70 71 72 73

82

89

81

88

80

79

78

77

87

86

85

76

75

74

84

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SYMPTOM PROCEDURES

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STEP 12. Check harness for open circuit or short circuit to 
ground between dual pressure switch connector A-22 
terminal 1 and PCM connector D-134 terminal 69.
Q: Is the harness wire in good condition?

YES : Go to Step 13.
NO :  Repair or replace the harness wire.

STEP 13. Check the dual pressure switch.
Refer to GROUP 55A, Dual Pressure Switch Check 

P.55A-118

.

Q: Is the switch operating properly?

YES : Go to Step 14.
NO :  Replace the dual pressure switch. Refer to GROUP 

55A, Refrigerant Line 

P.55A-152

.

AC204167

CONNECTOR : A-22

AV

A-22 (BR)

A-22

1 2

AC204681AC

CONNECTOR: D-134

D-134 (GR)

61 62

63 64

65 66 67 68 69 70 71 72 73

82

89

81

88

80

79

78

77

87

86

85

76

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STEP 14. Using scan tool MB991502, check data list item 
65: Dual Pressure Switch.

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 and run at idle.
(3) Set scan tool MB991502 to data reading mode for item65, 

Dual Pressure Switch.

• When the A/C is in operation, scan tool MB991502 dis-

play should be "ON."

• When the A/C is not in operation, scan tool MB991502 

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 :  Replace the PCM.

STEP 15. Check PCM connector D-134 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 14.
NO :  Repair or replace the damaged components. Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-

2

.

ACX01539AD

MB991502

16-PIN

AC204681AC

CONNECTOR: D-134

D-134 (GR)

61 62

63 64

65 66 67 68 69 70 71 72 73

82

89

81

88

80

79

78

77

87

86

85

76

75

74

84

83

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SYMPTOM PROCEDURES

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INSPECTION PROCEDURE 16: Transmission won’t Downshift Under Load with Auto-cruise Engaged.

.

CIRCUIT OPERATION
The overdrive-off signals are created inside the 
PCM. When a malfunction of the auto-cruise control 
circuit occurs, the transmission may downshift 
harshly with the auto-cruise control engaged.

.

COMMENT
A malfunction may be present on the auto-cruise sig-
nal line or the PCM.

.

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

• Malfunction of the PCM

DIAGNOSIS

Required Special Tool:

• MB991502: Scan Tool (MUT-II)

STEP 1. Using scan tool MB991502, check data list item 66: 
Overdrive Off Signal.

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 and prepare to test drive the vehicle. 

(Operate the auto-cruise)

(3) Set scan tool MB991502 to data reading mode for item 66, 

Overdrive Off Signal.

• When driving at level road, the display should be "OFF."

• When driving at uphill road, the display should be "ON."

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the PCM 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 the auto-cruise system.
Check the auto-cruise system. Refer to GROUP 17, Auto-
cruise Control System Diagnostic Troubleshooting Strategy 

P.17-8

.

Q: Is the auto-cruise system operating properly?

YES : Go to Step 3.
NO :  Repair it, then check the symptom.

ACX01539AD

MB991502

16-PIN