Mitsubishi Montero (2004+). Manual — part 899

AUTOMATIC TRANSMISSION DIAGNOSIS

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AUTOMATIC TRANSMISSION

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LOGIC FLOW CHARTS (Monitor Sequence)

.

DTC SET CONDITIONS

Check Conditions

• Transmission fluid temperature sensor voltage:

4.5 volts or less.

• Transmission range switch: D.

• Output speed: 900 r/min or more.

Judgement Criteria

• Vehicle speed: no signal change. (30 seconds)

.

OBD-II DRIVE CYCLE PATTERN
Start the engine, drive at 40 km/h (25 mph) or more
continuously for one minute.

.

TROUBLESHOOTING HINTS (THE MOST LIKELY
CAUSES FOR THIS CODE TO BE SET ARE:)

• Malfunction of the vehicle speed sensor circuit

• Damaged harness, connector

• Malfunction of the PCM

AC205180

START

N

OPG-B

: Output speed

(output shaft speed sensor)

Transmission range
switch position is in
D, 3, 2 or L range

Transmission fluid
temperature sensor
voltage < 4.5 V

N

OPG-B

> 900 r/min

Is there no input from
vehicle speed sensor

Continuous failure
for 30 secs.

Yes

No

Good

Malfunction

END

Yes

No

Yes

No

Yes

No

Yes

No

AB

Transmission range
switch position is in
D range

AUTOMATIC TRANSMISSION DIAGNOSIS

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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 speedometer.
Q: Is the speedometer operating properly?

YES : Go to Step 2.
NO : Check the vehicle speed sensor. Refer to GROUP

54A, Combination Meters Assembly and Vehicle
Speed Sensor

P.54A-77

.

STEP 2. Using scan tool MB991958, check data list item 29:
Vehicle Speed Sensor.

CAUTION

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

• Item 29: Vehicle Speed Sensor.

• Check that the speedometer and scan tool

MB991958 display speed match when driving at a
vehicle speed of 40 km/h (25 mph).

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor 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 3.

AC307591 AC

MB991911

MB991824

MB991827

AC307591

DATA LINK

CONNECTOR

AUTOMATIC TRANSMISSION DIAGNOSIS

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STEP 3. Using an oscilloscope, check the vehicle speed
sensor waveform at PCM connector D-134 by backprobing.
(1) Do not disconnect connector D-134.

(2) Connect an oscilloscope probe to PCM connector D-134

terminal 79 by backprobing.

(3) Start the engine and drive the vehicle.

(4) Check the vehicle speed sensor waveform.

• The vehicle speed sensor waveform should show a pat-

tern similar to the illustration when running the vehicle.

(5) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the waveform normal?

YES : Go to Step 6.
NO : Go to Step 4.

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

AC204946 AG

OSCILLO-
SCOPE

PROBE

D-134 HARNESS CONNECTOR :
HARNESS SIDE

76

85

65

72

71

73

82

75

81

74

63 64

66

70

69

68

67

78

87

79

88 89

80

77

86

62

61

83 84

ACX02131

NORMAL WAVEFORM

(V)

AC

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STEP 4. Check joint connector D-116, PCM connector
D-134 and intermediate connector E-111 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 5.
NO : Repair or replace the damaged components. Refer to

GROUP 00E, Harness Connector Inspection

P.00E-2

.

AC204171

CONNECTOR : D-116

AN

9 10

8

6 7

31 32

30

29

18 19 20 21

5

4

2

1

3

27

26

24

23

25

12 13 14 15 16 17

28

11
22
33

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

AC204176

CONNECTOR : E-111

BF

15

4

14

37

36

26 27

12

11

35

34

23 24

3

13

25

9

2

8

32

20 21

6

5

17

29

30

18

1

7

19

31

10

22

33

16

28

38