Mitsubishi Colt Ralliart. Manual - part 678

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-37

Code No. P0105: Barometric Pressure Sensor System

FUNCTION

• The barometric pressure sensor converts the bar-

ometric pressure to a voltage signal and inputs 
the signal to the engine-ECU.

• In response to the signal, the engine-ECU cor-

rects the fuel injection amount, etc.

TROUBLE JUDGEMENT

Check Conditions

• 2 seconds later from when ignition switch is in 

ON position

• Battery voltage is more than 8.0 V.

Or

• 2 seconds later from when engine starts

• Battery voltage is more than 8.0 V. 

Judgement Criterion

• Sensor output voltage is less than 0.2 V for 4 sec-

onds.

Or

• Sensor output voltage is more than 4.5 V for 4 

seconds.

PROBABLE CAUSE

• Failed barometric pressure sensor

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

• Reconfirmation of diagnosis code

Q: Is the diagnosis code output?

YES : 

Replace engine-ECU.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use 

Troubleshooting/Inspection Service Points 

− 

How to Cope with Intermittent Malfunctions 

P.00-13

).

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-38

Code No.P0110: Intake Air Temperature Sensor System

OPERATION

• A power voltage of 5 V is applied to the intake air 

temperature sensor (terminal No. 1) from the 
engine-ECU (terminal No. 129).

• The intake air temperature sensor (terminal No. 

4) is earthed to the engine-ECU (terminal No. 
102).

FUNCTION

• The intake air temperature sensor converts the 

intake air temperature into a voltage signal and 
inputs the signal to the engine-ECU.

• In response to the signal, the engine-ECU cor-

rects the fuel injection amount, etc.

• The intake air temperature sensor is a kind of 

resistor, which has the property of decreasing in 
resistance with the increase of intake air temper-
ature. Therefore, the sensor output voltage varies 
with the intake air temperature, lowering as the 
intake air temperature rises.

TROUBLE JUDGEMENT

Check Condition

• 2 seconds later from when ignition switch is in 

ON position

Or

• 2 seconds later from when engine starts

Judgement Criterion

• Sensor output voltage is more than 4.6 V for 4 

seconds. (Intake air temperature is less than 
-40

°C or equivalent.)

Or

• Sensor output voltage is less than 0.2 V for 4 sec-

onds. (Intake air temperature is more than 120

°C 

or equivalent.)

PROBABLE CAUSES

• Failed intake air temperature sensor

• Open/short circuit or damage in intake air temper-

ature sensor circuit or loose connector contact

• Failed engine-ECU

AK402714

1

2

3 4

R

92 93 94 95969798

77 78 79 808182838485868788899091

99

100

107 108 109 110 111112113114115116117118119120121
122 123 124 125126127128129130131132133134135136

101102103104105106

71 72

73 74

75 76

AE

102

129

Intake air temperature sensor
(Integrated in air flow sensor)

Engine-ECU

4

1

5 V

Intake Air Temperature Sensor Circuit

R-Y

B

A-34

A-08

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  P: Purple

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-39

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list

• Item 13: Intake air temperature sensor

OK: At ambient temperature (atmospheric 
temperature) or equivalent

Q: Is the check result normal?

YES : 

Intermittent malfunction (Refer to GROUP 

00 

− How to Use 

Troubleshooting/Inspection Service Points 

− 

How to Cope with Intermittent Malfunctions 

P.00-13

).

NO : 

Go to Step 2 .

STEP 2. Connector check: A-34 air flow sensor 
connector

Q: Is the check result normal?

YES : 

Go to Step 3 .

NO : 

Repair or replace.

STEP 3. Check intake air temperature sensor 
itself.

• Check intake air temperature sensor itself 

(

P.13B-364

).

Q: Is the check result normal?

YES : 

Go to Step 4 .

NO : 

Replace intake air temperature sensor.

STEP 4. Perform resistance measurement at A-34 
air flow sensor connector.

• Disconnect connector and measure at harness 

side.

• Resistance between terminal No. 4 and earth.

OK: Continuity (2 

Ω or less)

Q: Is the check result normal?

YES : 

Go to Step 8 .

NO : 

Go to Step 5 .

STEP 5. Connector check: A-08 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Go to Step 6 .

NO : 

Repair or replace.

AK402083

2

1

3

4

Connector: A-34

Harness side 

connector

A-34 (GR)

AC

AK402083

2

1

3

4

Connector: A-34

Harness side 

connector

A-34 (GR)

AC

AK402725

77

78

79

80

81

82

83

84

92

93

94

95

96

97

98

99

85

86

87

88

89

90

91

100

101

102

103

104

105

106

115

116

117

118

119

120

121

107

108

109

110

111

112

113

114

130

131

132

133

134

135

136

122

123

124

125

126

127

128

129

72 71

74 73

76 75

R

AI

A-08

Connector: 

A-08

A-08 Special tool power plant ECU check 
harness

Engine-ECU

Battery

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-40

STEP 6. Check harness between A-34 (terminal 
No. 4) air flow sensor connector and A-08 
(terminal No. 102) engine-ECU connector.

• Check earthing line for open circuit and damage.

Q: Is the check result normal?

YES : 

Go to Step 7 .

NO : 

Repair.

STEP 7. M.U.T.-III data list

• Item 13: Intake air temperature sensor

OK: At ambient temperature (atmospheric 
temperature) or equivalent

Q: Is the check result normal?

YES : 

Intermittent malfunction (Refer to GROUP 

00 

− How to Use Troubleshooting/Inspection 

Service Points 

− How to Cope with 

Intermittent Malfunctions 

P.00-13

).

NO : 

Replace engine-ECU.

STEP 8. Perform voltage measurement at A-34 air 
flow 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 13 .

NO : 

Go to Step 9 .

AK402083

2

1

3

4

Connector: A-34

Harness side 

connector

A-34 (GR)

AC

AK402725

77

78

79

80

81

82

83

84

92

93

94

95

96

97

98

99

85

86

87

88

89

90

91

100

101

102

103

104

105

106

115

116

117

118

119

120

121

107

108

109

110

111

112

113

114

130

131

132

133

134

135

136

122

123

124

125

126

127

128

129

72 71

74 73

76 75

R

AI

A-08

Connector: 

A-08

A-08 Special tool power plant ECU check 
harness

Engine-ECU

Battery

AK402083

2

1

3

4

Connector: A-34

Harness side 

connector

A-34 (GR)

AC

Main

Index

Group

TOC