Mitsubishi Colt Ralliart. Manual — part 741

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-289

STEP 14. Check harness between A-08 (terminal
No. 75 and No. 76) engine-ECU connector and
body earth.

•

Check earthing line for open circuit and damage.

Q: Is the check result normal?

YES :

Replace engine-ECU.

NO :

Repair.

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-290

Inspection Procedure 22: Fuel Pump System

AK402703

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

3

1

2

4

3

1

2

4

1 2 3
4 5 6

M

1

2 3

4

5

Fuel pump
and gauge
unit

IG2

ST

LOCK

ACC

IG1

R

38

7.5A

17

1

15A

B-141

J/B

Ignition switch

Fuel
pump
relay (1)

Fuel
pump
relay (2)

Fuel Pump Circuit

2

R

L-B

OFF

ON

OFF

ON

B-103

B-117

81

13

5

4

V

7

3

3

1

4

2

3

1

4

2

1

8

B-129

B-130

B-110

B-128

B-108

B-L

B

B

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

AE

A-08

Engine-ECU

Fusible link

C-16
(MU802058)

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-291

OPERATION

• The battery voltage is applied to the fuel pump

relay (1) (terminal No. 1) from the ignition switch
and is earthed to the vehicle body from the fuel
pump relay (1) (terminal No. 2).

• The battery voltage is applied to the fuel pump

relay (1) (terminal No. 3) and to the fuel pump
relay (2) (terminal No. 3) from the fuel pump relay
(1) (terminal No. 4).

• The battery voltage is applied to the fuel pump

relay (2) (terminal No. 1) from the ignition switch.
The engine-ECU (terminal No. 81) makes the
power transistor in the unit be in ON position and
makes currents go on the fuel pump relay (2) coil,
and that makes the relay be in ON position.

• When the fuel pump relay (2) is in ON position,

the battery voltage is supplied to the fuel pump
from the fuel pump relay (2) (terminal No. 4).

FUNCTION

• When the ignition switch ON signal is input to the

engine-ECU, the engine-ECU places the fuel
pump relay (2) in the ON position. Accordingly,
the battery voltage is supplied to the fuel pump.

PROBABLE CAUSES

• Failed fuel pump relay

• Failed fuel pump

• Open/short circuit in or damage to the fuel pump

drive circuit or loose connector contact

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-103 fuel pump relay
(2) connector and B-117 fuel pump relay (1)
connector

Q: Is the check result normal?

YES :

Go to Step 2 .

NO :

Repair or replace.

STEP 2. Check fuel pump relay.

• Fuel pump relay, continuity check (Refer to

P.13B-363

).

Q: Is the check result normal?

YES :

Go to Step 3 .

NO :

Replace fuel pump relay.

AK402109

3

2

1

4

AC

J/B side
connector

Connector: B-103, B-117
J/B (front side)

B-117

B-103

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-292

STEP 3. Perform resistance measurement at
B-117 fuel pump relay (1) connector.

• Remove relay, and measure at connector side.

• Resistance between terminal No. 2 and earth.

OK: Continuity (2

Ω or less)

Q: Is the check result normal?

YES :

Go to Step 4 .

NO :

Check intermediate connector B-130, and

repair if necessary. If intermediate
connector is normal, check and repair
harness between B-117 (terminal No. 2) fuel
pump relay (1) connector and body earth.

• Check earthing line for open circuit

and damage.

STEP 4. Perform voltage measurement at B-117
fuel pump relay (1) connector.

• Remove relay, and measure at connector side.

• Ignition switch: ON

• Voltage between terminal No. 1 and earth.

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 6 .

NO :

Go to Step 5 .

AK402110

3

2

1

4

AC

J/B side
connector

Connector: B-117
J/B (front side)

B-117

AK402110

3

2

1

4

AC

J/B side
connector

Connector: B-117
J/B (front side)

B-117

Main

Index

Group

TOC