Mitsubishi Colt Ralliart. Manual — part 98

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-346

NOTE: *:The average voltage is shown when an
analog voltmeter is used (because the average volt-
age might not be shown stably when digital voltmeter
is used).

81

A/C relay

• Engine: Idle speed

• A/C switch: OFF → ON (A/C compressor is

operating)

System voltage

→ 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 V or more

95

Fan control relay

Fan inactive state

System voltage

Fan low-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

110

Fuel pump relay

Ignition switch: ON

System voltage

Engine: Idle speed

1 V or less

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

Release the brake pedal

1 V or less

Depress the brake pedal

System voltage

Terminal
No.

Check item

Check condition (Engine condition)

Normal condition

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-347

CHECK CHART FOR RESISTANCE AND
CONTINUITY BETWEEN TERMINALS

1. Turn the ignition switch to "LOCK" (OFF) position.
2. Disconnect the engine-ECU connector or

engine-CVT-ECU connector.

3. Measure the resistance and check for continuity

between the terminals of the engine-ECU <M/T>
or engine-CVT-ECU <CVT> 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 <M/T> or
engine-CVT-ECU <CVT> and/or ohmmeter. 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 <M/T> or Engine-CVT-ECU <CVT> Harness Side Connector Terminal
Arrangement

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

AG

Engine-ECU <M/T> or Engine-CVT-ECU <CVT>

Harness Side Connector

Terminal
No.

Inspection item

Normal condition (Check condition)

5

− 92

EGR valve (A) <CVT>

20

− 24 Ω (at 20°C)

6

− 92

EGR valve (B) <CVT>

53

− 92

EGR valve (C) <CVT>

54

− 92

EGR valve (D) <CVT>

7

− 22

Throttle valve control servo

0.3

− 100 Ω (at 20°C)

8

− 92

No. 1 injector

14

− 15 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 coolant temperature is −20°C)

5.1

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

2.1

− 2.7 kΩ (When coolant temperature is 20°C)

0.9

− 1.3 kΩ (When coolant temperature is 40°C)

0.48

− 0.68 kΩ (When coolant temperature is 60°C)

0.26

− 0.36 kΩ (When coolant temperature is 80°C)

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-348

INSPECTION PROCEDURE USING
OSCILLOSCOPE

M1131154501728

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. Connect the oscilloscope special pattern pickup to

camshaft position sensor terminal No. 2.

3. Disconnect the crank angle sensor intermediate

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

4. Connect the oscilloscope special patterns pickup

to crank angle sensor terminal No. 2.

Alternate Method (Test harness not
available)

1. Disconnect the engine-ECU connector or

engine-CVT-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 <M/T> or engine-CVT-ECU
<CVT> terminal No. 12 (When checking the
camshaft position sensor signal wave pattern).

3. Connect the oscilloscope special patterns pickup

to engine-ECU <M/T> or engine-CVT-ECU
<CVT> terminal No. 13 (When checking the crank
angle sensor signal wave pattern).

33

− 56

Intake air temperature sensor

13

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

5.3

− 6.7 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)

0.30

− 0.42 kΩ (When intake air temperature is 80°C)

38

− 92

Purge control solenoid valve

30

− 34 Ω (at 20°C)

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)

75

− Body

earth

Engine-ECU <M/T> or
engine-CVT-ECU <CVT> earth

Continuity (2

Ω or less)

76

− Body

earth
93

− Body

earth
108

−

Body
earth
79

− 92

Oxygen sensor heater (rear)

5

− 30 Ω (at 20°C)

Terminal
No.

Inspection item

Normal condition (Check condition)

1 2 3

3

2

1

AK304513

Special patterns
pick-up

Oscilloscope

AC

Camshaft position
sensor connector

Crank angle sensor
intermediate
connector

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-349

Standard Wave Pattern

Observation condition

Wave Pattern Observation Points

Check that cycle time T becomes shorter when the
engine speed increases.

Examples of Abnormal Wave Patterns

•

Example 1

Cause of problem
Sensor interface malfunction

Wave pattern characteristics
Rectangular wave pattern is output even when

the engine is not started.

•

Example 2

Cause of problem
Loose timing belt
Abnormality in sensor disk
Wave pattern characteristics
Wave pattern is displaced to the left or right.

Function

Special patterns

Pattern height

Low

Pattern selector

Display

Engine speed

Idle

AK204111AC

(V)

5

0

5

0

No. 1TDC

No. 3TDC

No. 4TDC

No. 2TDC

time

Standard wave pattern

Crank angle
sensor output
wave pattern

Camshaft position
sensor output
wave pattern

2 engine revolutions
(1 camshaft revolution)

TDC: Top dead centre

AK304525

AK203244

Main

Index

Group

TOC