Mitsubishi Montero (2004+). Manual — part 944

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-351

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-112

.

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-146

.

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

75

74

84

83

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-352

STEP 14. Using scan tool MB991958, check data list item
65: Dual Pressure 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) Start the engine and run at idle.
(3) Set scan tool MB991958 to data reading mode.

• Item65: Dual Pressure Switch.

• When the A/C is in operation, scan tool MB991958

display should be "ON."

• When the A/C is not in operation, 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 : 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

.

AC307591 AC

MB991911

MB991824

MB991827

AC307591

DATA LINK

CONNECTOR

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

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-353

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:

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

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B

STEP 1. Using scan tool MB991958, check data list item 66:
Overdrive Off Signal.

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) Start the engine and prepare to test drive the vehicle.

(Operate the auto-cruise)

(3) Set scan tool MB991502 to data reading mode.

• 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 Strat-
egy

P.17-12

.

Q: Is the auto-cruise system operating properly?

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

AC307591 AC

MB991911

MB991824

MB991827

AC307591

DATA LINK

CONNECTOR

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION

23A-354

STEP 3. Using scan tool MB991958, check data list item 66:
Overdrive Off Signal.

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) Start the engine and prepare to test drive the vehicle.

(Operate the auto-cruise)

(3) Set scan tool MB991502 to data reading mode.

• 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 : Replace the PCM.

AC307591 AC

MB991911

MB991824

MB991827

AC307591

DATA LINK

CONNECTOR