Mitsubishi Evolution X. Manual - part 119

CONTROL UNIT

TSB Revision

MULTIPORT FUEL SYSTEM (MFI)

13A-5

CONTROL UNIT

M2132021500391

ENGINE CONTROL MODULE (ECM)

ECM is installed in the engine room. ECM judges 
(calculates) the optimum control to deal with the con-
stant minute changes in driving conditions based on 
information input from the sensors and drives the 
actuator. ECM is composed of 32-bit microprocessor 
and Random Access Memory (RAM), Read Only 
Memory (ROM) and Input /Output interface. ECM 

uses flash-memory ROM that allows re-writing of 
data so that change and correction of control data is 
possible using special tools. It also uses Electrically 
Erasable Programmable Read Only Memory 
(EEPROM) so that studied compensation data is not 
deleted even if battery terminals are disconnected.

AK604119

ECM

Microprocessor

RAM

Input 
interface

Output 
interface

Input 
sensor

Output
actuator 

AB

ROM

CONTROL UNIT

TSB Revision

MULTIPORT FUEL SYSTEM (MFI)

13A-6

ECM CONNECTOR INPUT/OUTPUT PIN ARRANGEMENT

AK704675 AB

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

91

90

89

87

86

84

85

83

82

88

92

93

94

95

96

97

98

99

109

108

107

106

105

104

103

102

112

113

114

115

116

117

118

100

101

111

110

41

40

39

38

37

36

35

34

33

32

31

30

29

28

27

26

25

24

23

22

60

59

58

57

56

55

54

53

52

51

50

49

48

47

46

45

44

43

42

63

61

62

64

71

72

73

74

75

76

77

78

79

80

81

1

Intake engine oil control valve

2

No.1 injector

3

No.2 injector

4

No.1 ignition coil (ignition power 
transistor)

5

No.2 ignition coil (ignition power 
transistor)

6

Starter active signal

7

Exhaust camshaft position sensor

8

Crankshaft position sensor

9

Sensor supplied voltage

10

Throttle position sensor (main)

11

Throttle position sensor (sub)

12

Power supply voltage applied to throttle 
position sensor 

13

Throttle position sensor ground

14

Intake camshaft position sensor

15

Throttle actuator control motor (+)

16

Throttle actuator control motor (-)

17

Exhaust engine oil control valve

18

No.3 injector

19

No.4 injector

20

No.3 ignition coil (ignition power 
transistor)

21

No.4 ignition coil (ignition power 
transistor)

23

Exhaust camshaft position sensor 
ground

24

Crankshaft position sensor ground

25

Knock sensor (+)

26

Engine coolant temperature sensor

27

Engine coolant temperature sensor 
ground

30

Intake camshaft position sensor ground 34

Heated oxygen sensor (front) heater

35

Heated oxygen sensor (rear) heater 

36

Engine oil pressure switch 

37

Evaporative emission purge solenoid 

38

Heated oxygen sensor (front)

39

Heated oxygen sensor (front) offset 
voltage

40

Heated oxygen sensor (rear)

41

Heated oxygen sensor (rear) offset 
voltage

42

Knock sensor (

−)

44

Power supply voltage applied to 
manifold absolute pressure sensor

45

Manifold absolute pressure sensor

46

Manifold absolute pressure sensor 
ground

51

Fuel pump relay 1

52

Turbocharger wastegate solenoid 1

53

Turbocharger wastegate solenoid 2

58

Power steering pressure switch

60

Generator G terminal

61

Generator FR terminal

62

Generator L terminal

SENSOR

TSB Revision

MULTIPORT FUEL SYSTEM (MFI)

13A-7

SENSOR

M2132001000811

.

MASS AIRFLOW SENSOR

Mass airflow sensor is installed in the air intake hose. Mass air-
flow sensor is composed of an extremely small heatsensing 
resistor. The mass airflow sensor controls the amount of elec-
tric current flowing into the heat sensing resistor to keep the 
heat sensing resistor at a constant temperature to the intake air 
temperature. When the air mass flow rate increases, the air 
flow speed is higher and also the amount of heat transfer from 
the heat sensing resistor to the air increased. Therefore, the 
mass airflow sensor increases the amount of electric current to 
the heat sensing resistor. Thus, the amount of electric current 
increases in accordance with the air mass flow rate. The mass 
airflow sensor measures the air mass flow rate by detecting the 
amount of electric current. The mass airflow sensor amplifies 
the detected electric current amount and outputs it into the 
ECM. ECM uses this output current and engine speed to calcu-
late and decide basic fuel injection time. Sensor properties are 
as shown in the figure.

71

Throttle actuator control motor ground

72

Throttle actuator control motor power 
supply

73

MFI relay (power supply)

74

Accelerator pedal position sensor 
(main)

75

Power supply voltage applied to 
accelerator pedal position sensor 
(main)

76

Accelerator pedal position sensor 
(main) ground

77

Accelerator pedal position sensor (sub) 78

Power supply voltage applied to 
accelerator pedal position sensor (sub)

79

Accelerator pedal position sensor (sub) 
ground

81

ECM ground

82

Power supply

83

Throttle actuator control motor ground

84

Throttle actuator control motor relay

85

Clutch pedal position switch <M/T>

87

Mass airflow sensor

88

Mass airflow sensor ground

89

Intake air temperature sensor 1

90

CAN interface (high)

91

CAN interface (low)

92

Ignition switch-IG

93

ECM ground

96

Fuel pump relay 2

97

Intake air temperature sensor 2 ground 98

Intake air temperature sensor 2

102

A/C compressor relay

103

Flash EP-ROM power supply

104

Backup power supply

105

Ignition switch-ST

106

Starter relay

112

Fuel tank differential pressure sensor

113

Fuel tank differential pressure sensor 
ground

114

Power supply voltage applied to fuel 
tank differential pressure sensor

115

Fuel tank temperature sensor

117

Evaporative emission ventilation 
solenoid

AK602252AC

Sensing area

Silicon substrate

Heat sensing
resistor

Intake air

Diaphragm

SENSOR

TSB Revision

MULTIPORT FUEL SYSTEM (MFI)

13A-8

.

INTAKE AIR TEMPERATURE SENSOR 1

Intake air temperature sensor 1 is built in to the mass airflow 
sensor. Intake air temperature sensor 1 detects intake air tem-
perature through thermistor's resistance change and outputs 
the voltage according to intake air temperature to ECM. ECM 
uses this output voltage to compensate fuel injection control 
and ignition timing control. Sensor properties are as shown in 
the figure.

.

AK602221AG

From MFI relay

Mass airflow sensor

ECM

Output current mA

Mass flow g/s

AK602253AC

Sensory part
(thermistor)

AK602207

Intake air
temperature ˚C (˚F)

AG

Resistance k

Ω

Output voltage V

Intake air temperature
sensor (thermistor)

5V

Intake air
temperature ˚C (˚F)

ECM