Mitsubishi Colt Ralliart. Manual - part 756

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-349

65

Alternator FR 
terminal

• Engine: Idling after warm-up

• Radiator fan: Inoperative

• Headlamp switch: OFF → ON

• Stop lamp: OFF → ON

• Rear defogger switch: OFF → ON

Voltage decreases

77

Power supply

Ignition switch: ON

System voltage

92
78

Power supply for 
throttle valve control 
servo

Ignition switch: ON

System voltage

79

Oxygen sensor 
(rear) heater

Engine: Idling

1 V or less

Engine: 5,000 r/min

System voltage

81

Fuel pump relay

Ignition switch: ON

System voltage

Engine: Idling

1 V or less

82

Backup power 
supply

Ignition switch: "LOCK" (OFF) 

System voltage

83

Accelerator pedal 
position sensor 
(main)

Ignition switch: ON

Release the 
accelerator pedal

0.8 

− 1.2 V

Depress the 
accelerator pedal 
fully

4.0 V or more

85

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

Ignition switch: ON

4.9 

− 5.1 V

86

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

Ignition switch: ON

4.9 

− 5.1 V

88

Accelerator pedal 
position sensor (sub)

Ignition switch: ON

Release the 
accelerator pedal

0.3 

− 0.7 V

Depress the 
accelerator pedal 
fully

2.0 V or more

90

Airflow sensor

Raise engine speed gradually

Voltage rises with engine 
speed

95

Cooling fan control 
relay (Lo) 

Fan inactive state

System voltage

Fan low-speed rotation state

1 V or less

96

Cooling fan control 
relay (Hi) 

Fan inactive state

System voltage

Fan high-speed rotation state

1 V or less

97

Oxygen sensor 
(rear)

Engine: Running at 2,500 r/min after warmed 
up

0.2 

− 0.8 V (After several 

seconds have elapsed)

107

Engine control relay Ignition switch: "LOCK" (OFF) 

System voltage

Ignition switch: ON

1 V or less

Terminal 
No.

Check item

Check condition (Engine condition)

Normal condition

Main

Index

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TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-350

110

A/C relay

• Engine: Idling

• A/C switch: OFF → ON

(A/C compressor is operating)

System voltage

122

Ignition switch - IG

Ignition switch: ON

System voltage

123

Throttle valve control 
servo relay

Ignition switch: "LOCK" (OFF) 

0 

− 0.1 V

Ignition switch: ON

1 V or less

128

Stop lamp switch

Depress the brake pedal

System voltage

Release the brake pedal

1 V or less

129

Intake air 
temperature sensor

Ignition switch: ON

When intake air 
temperature is 

−20°C

3.8 

− 4.4 V

When intake air 
temperature is 0

°C

3.2 

− 3.8 V

When intake air 
temperature is 20

°C

2.3 

− 2.9 V

When intake air 
temperature is 40

°C

1.5 

− 2.1 V

When intake air 
temperature is 60

°C

0.8 

− 1.4 V

When intake air 
temperature is 80

°C

0.4 

− 1.0 V

Terminal 
No.

Check item

Check condition (Engine condition)

Normal condition

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TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-351

CHECK CHART FOR RESISTANCE AND 
CONTINUITY BETWEEN TERMINALS

1. Turn the ignition switch to "LOCK" (OFF) position.
2. Disconnect the engine-ECU connector.
3. Measure the resistance and check for continuity 

between the terminals of the engine-ECU 
harness-side connector while referring to the 
check chart.
NOTE: 

.

1. When measuring resistance and checking 

continuity, a harness for checking contact pin 
pressure should be used instead of inserting a 
test probe.

2. Checking need not be carried out in the order 

given in the chart.

CAUTION

If the terminals that should be checked are mis-
taken, or if connector terminals are not correctly 
shorted to earth, damage may be caused to the 
vehicle wiring, sensors, engine-ECU and/or ohm-
meter. Be careful to prevent this!
4. If the ohmmeter shows any deviation from the 

standard value, check the corresponding sensor, 
actuator and related electrical wiring, and the 
repair or replace.

5. After repair or replacement, recheck with the 

ohmmeter to confirm that the repair or 
replacement has corrected the problem.

Engine-ECU Harness Side Connector

AK402726

61

46

31

64

49

19
34

50

51
6665

36

21

35

20

47

48
6362

33

18

32

17

58

43

28

44

45
6059

30

1615

29

14

41

42
5756

27

12

13

26

11

53

38

23

8

39

40

54

55

24

9

L

25

10

37
52

22

7

5

3

1

6

4

2

93

71

72

75

73

76

74

92

77

98

83

95 94

R

96

97

80

78

79

81

82

99

86

84

85

107
122

108
123

109
124

110
125

111
126

112
127

113
128

114
129

115
130

116
131

117
132

118
133

119
134

120
135

121
136

101100

102

103

104

105

106

87

88

919089

A-114

A-08

AC

Engine-CVT-ECU Harness Side Connector 

Terminal 
No.

Inspection item

Normal condition (check condition)

7 

− 22

Throttle valve control servo

0.3 

− 100 Ω (at 20°C) 

8 

− 92

No. 1 injector

10.5 

− 13.5 Ω (at 20°C) 

9 

− 92

No. 2 injector

23 

− 92

No. 3 injector

24 

− 92

No. 4 injector

14 

− 29

Engine coolant temperature sensor

14 

− 17 kΩ (When engine coolant temperature is 

−20°C) 
5.1 

− 6.5 kΩ (When engine coolant temperature is 0°C)

2.1 

− 2.7 kΩ (When engine coolant temperature is 

20

°C) 

0.9 

− 1.3 kΩ (When engine coolant temperature is 

40

°C) 

0.48 

− 0.68 kΩ (When engine coolant temperature is 

60

°C) 

0.26 

− 0.36 kΩ (When engine coolant temperature is 

80

°C) 

36 

− 92

Waste gate solenoid valve

29 

− 35 Ω (at 20°C) 

38 

− 92

Purge control solenoid valve

30 

− 34 Ω (at 20°C) 

Main

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TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-352

INSPECTION PROCEDURE USING 
OSCILLOSCOPE

M1131154501739

The output signals of the sensors and the conditions 
of the actuation signals of the actuators can be 
inspected visually by observing the waveforms on 
the oscilloscope.

CAMSHAFT POSITION SENSOR AND 
CRANK ANGLE SENSOR
Measurement Method

1. Disconnect the camshaft position sensor 

connector and connect the special tool test 
harness (MB991709) in between (All terminals 
should be connected).

2. Disconnect the crank angle sensor intermediate 

connector and connect the special tool test 
harness (MB991658) in between.

3. Connect the probe of each channel of the 

oscilloscope to camshaft position sensor 
connector terminal No. 2 and crank angle sensor 
intermediate connector terminal No. 2.

Alternate Method (Test harness not 
available)

1. Disconnect the engine-ECU connector and 

connect the special tool Power plant ECU check 
harness (MB991987) in between.

2. Connect the oscilloscope special patterns pickup 

to engine-ECU terminal No. 12 (When checking 
the camshaft position sensor signal wave pattern).

3. Connect the oscilloscope special patterns pickup 

to engine-ECU terminal No. 13 (When checking 
the crank angle sensor signal wave pattern).

51 

− 92

Oxygen sensor heater (front)

5 

− 30 Ω (at 20°C) 

52 

− 92

Oil feeder control valve

6.9 

− 7.9 Ω (at 20°C)

57 

− 92

Fuel pressure solenoid valve

29 

− 35 Ω (at 20°C)

75 

− Body 

earth

ECU earth

Continuity (2 

Ω or less)

76 

− Body 

earth
93 

− Body 

earth
108 

− 

Body 
earth
129 

− 102 Intake air temperature sensor

13 

− 17 kΩ (When intake air temperature is −20°C)

5.4 

− 6.6 kΩ (When intake air temperature is 0°C) 

2.3 

− 3.0 kΩ (When intake air temperature is 20°C) 

1.0 

− 1.5 kΩ (When intake air temperature is 40°C) 

0.56 

− 0.76 kΩ (When intake air temperature is 60°C) 

0.31 

− 0.43 kΩ (When intake air temperature is 80°C) 

79 

− 92

Oxygen sensor heater (rear)

5 

− 30 Ω (at 20°C)

Terminal 
No.

Inspection item

Normal condition (check condition)

2 3

3

2

1

1

AK203241

Crank angle sensor 
intermediate
connector

Oscilloscope

Camshaft position
sensor connector

AD

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