Mitsubishi Lancer Evolution IX. Manual - part 433

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-207

STEP 11. Check harness between B-25 (terminal 
No. 4) alternator connector and B-14 (terminal 
No. 5) intermediate connector.

• Check output line for damage.

Q: Is the check result normal?

YES : 

Go to Step 12 .

NO : 

Repair the damaged harness wire.

STEP 12. Check harness between B-14 (terminal 
No. 5) intermediate connector and C-119 
(terminal No. 52) engine-ECU connector.

• Check output line for damage.

Q: Is the check result normal?

YES : 

Go to Step 13 .

NO : 

Repair the damaged harness wire.

STEP 13. Check the trouble symptoms.

Q: Does trouble symptom persist?

YES : 

Replace the alternator.

NO : 

Intermittent malfunction (Refer to Group 00 
− How to Use troubleshooting/Inspection 
Service Points 

P.00-5

).

AK305036

M

2

1

3

4

Harness side 
connector

AB

Connector : B-25

B-25(GR)

AK305035

3

4

5

8

9

1

2

6

7

10

Connector : B-14

Female side 
connector

B-14(B)

AC

AK401753

1

2 3

6

7 8

4 5

9 10

Connector : B-14

Male side 
connector

B-14(B)

AB

AK501994

65

43
50

42
49

41
48
60

61

64

46

47

58

59

67

68

45

56
66

52 51

44

53

62

54

63

57

55

AB

Connector: C-119

C-119 (GR)

C-119 (GR)

Harness side connector

<L. H. drive vehicles>

<R. H. drive vehicles>

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-208

Code No. P0710: Transmisson Oil Temperature Sensor System

OPERATION

• A power voltage of 5 V is applied to the transmis-

sion oil temperature sensor output terminal (ter-
minal No. 1) from the engine-ECU (terminal No. 
96).

• The power voltage is earthed to the engine-ECU 

(terminal No. 49) from the transmission oil tem-
perature sensor (terminal No. 2).

FUNCTION

• The transmission oil temperature sensor converts 

the transmission oil temperature into a voltage 
signal, and inputs the voltage to the engine-ECU.

• The engine-ECU controls the boost pressure, 

based on this signal.

• The transmission oil temperature sensor is a kind 

of resistor, which has characteristics to reduce its 
resistance as the transmission oil temperature 
rises. Therefore, the sensor output voltage varies 
with the transmission oil temperature, and 
becomes lower as the transmission oil tempera-
ture rises.

TROUBLE JUDGMENT

Check Conditions

• 2 seconds later after the ignition switch has been 

in "ON" position or the engine has started up.

• The engine coolant temperature of 82°C or more.

Judgment Criteria

• The sensor output voltage of 4.8 V or more 

(transmission oil temperature of 

−40°C or equiva-

lent) for 2 seconds,

or

1 2

AK501821

65

43
50

42
49

41
48
60 61

64

46 47
58 59
67 68

45

56
66

52

51

44

53

62

54

63

57

55

80

87

81

94

85

82

84

93

86

98

99

74

92

73

83

88

91

95

97

96

100

89

78

71

90

76 77

75

72
79

5 V

49

96

B

B

G-R

G-R

Engine-ECU

Transmission oil temperature sensor

B-30

(MU802406)

2

1

2

1

Transmission oil temperature sensor circuit

Wire colour code
B: Black  LG: Light green  G: Green  L: Blue  W: White  Y: Yellow  SB: Sky blue  BR: Brown  O: Orange  GR: Gray
R: Red  P: Pink  V: Violet  PU: Purple

C-119

(MU803782)

AB

B-27

C-117

(MU803783)

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-209

• The sensor output voltage of 0.1 V or less (trans-

mission oil temperature of 150

°C or more, or 

equivalent) for 2 seconds.

PROBABLE CAUSES

• Failed transmission oil temperature sensor

• Open/short circuit in transmission oil temperature 

sensor circuit or loose connector contact

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-30 transmission oil 
temperature sensor connector

Q: Is the check result normal?

YES : 

Go to Step 3 .

NO : 

Repair or replace the connector.

STEP 2. Perform resistance measurement at B-30 
transmission oil temperature sensor connector.

• Disconnect connector, and measure at sensor 

side.

• Resistance between terminal No. 1 and No. 2.

OK:

Transmission oil temperature at 

−20°C: 14 − 17 

k

Ω

Transmission oil temperature at 0

°C: 5.1 − 6.5 

k

Ω

Transmission oil temperature at 20

°C: 2.1 − 2.7 

k

Ω

Transmission oil temperature at 40

°C: 0.9 − 1.3 

k

Ω

Transmission oil temperature at 60

°C: 0.48 − 

0.68 k

Ω

Transmission oil temperature at 80

°C: 0.26 − 

0.36 k

Ω

Q: Is the check result normal?

YES : 

Go to Step 3 .

NO : 

Replace the transmission oil temperature 
sensor.

AK502000

1

2

AB

Connector: B-30

B-30 (B)

Harness side 
connector

AK502000

1

2

AB

Connector: B-30

B-30 (B)

Harness side 
connector

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-210

STEP 3. Perform voltage measurement at B-30 
transmission oil temperature sensor connector.

• Disconnect connector, and measure at harness 

side.

• Ignition switch: "ON"

• Voltage between terminal No. 1 and earth.

OK: 4.5 

− 4.9 V

Q: Is the check result normal?

YES : 

Go to Step 9 .

NO : 

Go to Step 4 .

STEP 4. Perform voltage measurement at C-117 
engine-ECU connector.

• Measure engine-ECU terminal voltage.

• Disconnect B-30 transmission oil temperature 

sensor.

• Ignition switch: "ON"

• Voltage between terminal No. 96 and earth.

OK: 4.5 

− 4.9 V

Q: Is the check result normal?

YES : 

Go to Step 5 .

NO : 

Go to Step 6 .

AK502000

1

2

AB

Connector: B-30

B-30 (B)

Harness side 
connector

AK501996

80

87

81

94

85

82

84

93

86

98

99

74

92

73

83

88

91

95

97 96

100

89

78

71

90

76

77

75

72
79

AB

Connector: C-117

C-117 (GR)

C-117 (GR)

Harness side connector

<L. H. drive vehicles>

<R. H. drive vehicles>