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

Group

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

Main

Index

Group

TOC

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

Index

Group

TOC

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

Main

Index

Group

TOC