Mitsubishi Eclipse / Eclipse Spyder (2000-2002). Service and repair manual — part 322

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-487

INSPECTION PROCEDURE 29: Power supply system and ignition switch-IG system.

AK000716

4

1 2

3

6

2 3

4 5 6

GREEN

1

1

3

2

4

1

4

8

7

2

6

3

5

5

BLA

CK-

WHITE

BLA

CK-

WHITE

BLA

CK-

WHITE

ORANGE-

BLA

CK

ORANGE-

BLA

CK

ORANGE-

BLA

CK

ORANGE-

BLA

CK

RED

RED

RED

WHITE-VIOLET

RED-

WHITE

RED-

WHITE

BLA

CK

BLA

CK

BLA

CK

BLA

CK

BLA

CK

R

IG2

ST

LOCK

ACC

IG1

C-87

C-87

C-101
MU801331

C-101

IGNITION
SWITCH

2

6

5

JUNCTION
BLOCK

99<M/T>*2
98<A/T>*4

C-07
MU801333

C-07

60<M/T>*1
66<A/T>*3

MFI
RELAY

A-21X

A-21X

3

4

1

2

57<M/T>*1
49<A/T>*3

BATTERY
BACK UP

47<M/T>*1
47<A/T>*3

59<M/T>*1
41<A/T>*3

POWER
SOURCE

58<M/T>*1
48<A/T>*3

46<M/T>*1
42<A/T>*3

ENGINE CONTROL MODULE(ECM)<M/T> OR
POWERTRAIN CONTROL MODULE(PCM)<A/T>

3

29

NOTE
*1:ECM connector C-58<M/T>
*2:ECM connector C-62<M/T>
*3:PCM connector C-55<A/T>
*4:PCM connector C-59<A/T>

65

43
50

42
49

41
48
60 61

64

46 47
58 59
67 68

45

56
66

52

51

44

53

62

54

63

57

55

C-58<M/T>
(MU803782)

C-55<A/T>
(MU803781)

42 43
48 49 50 51 52 53 54 55 56 57

46

45

44

58 59

60 61 62 63

64 65 66

47

41

98

78

71

88 89

76 77

72
79
91

73
80

74

75

81
92

82 83
93

84 85

94

86 87

95 96

90

80

87

81

94

85

82

84

93

86

98

99

74

92

73

83

88

91

95

97

96

100

89

78

71

90

76 77

75

72
79

97

C-62<M/T>
(MU803783)

C-59<A/T>
(MU803782)

15 16

26 27 28 29

32 33 34

17 18 19 20 21 22 23 24 25

30 31

36 37

35

38

10

11 12 13

1 2 3

4 5 6 7 8 9

14

C-89

C-89

C-28

C-78

7 8

5

3 4

35

34

10 11 12

2122 23 24

13 14 15

25 26 27

16

28

17

18 19 20

29

30 31

32 33

36 37

38

9

1 2

6

16

15

18

17

14

20

22

21

9

7

1 2

5

19

3

33

32

30 31

29

28

25

24

23

27

26

6

11

13

4

10

8

12

WHITE

WHITE

BATTERY

DEDICATED
FUSE

13

4

RED-

WHITE

RED-

WHITE

8

C-07

25

C-89

27

C-28

6

9

JOINT
CONNECTOR

C-78

JOINT
GROUND
POINT

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-488

CIRCUIT OPERATION

•

Battery positive voltage is applied to the MFI
relay (terminals 3, 4).

•

When the ignition switch is turned to the "ON"
position, The battery positive voltage is applied to
the ECM (terminal 99) <M/T> or PCM (terminal
98) <A/T>. When the battery positive voltage is
applied, the ECM <M/T> or PCM <A/T> turns the
power transistor in the ECM <M/T> or PCM <A/

T> "ON" and grounds the MFI relay coil. With
this, the MFI relay turns "ON" and the battery
positive voltage is supplied to the ECM (terminal
47, 59) <M/T> or PCM (terminal 41, 47) <A/T>
from the MFI relay (terminal 1).

•

Battery positive voltage is constantly supplied to
the ECM (terminal 60) <M/T> or PCM (terminal
66) <A/T> as the backup power.

AK000225

CONNECTORS : C-58, C-62<M/T>,
C-55, C-59<A/T>

C-55

C-58

PCM<A/T>

ECM<M/T>

AK

C-59

C-62

AK000345AE

CONNECTOR:C-89

AK000219

CONNECTOR:C-87

AC

AK000312AJ

CONNECTOR:C-07

AK000226

AK000226AB

CONNECTOR : A-21X

MFI RELAY

AK000733AC

CONNECTOR:C-28

AK000315

CONNECTOR:C-101

AC

AK000312AG

CONNECTOR:C-78

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-489

•

The ECM (terminal 46, 58) <M/T> or PCM
(terminals 42, 48) <A/T> is grounded to the
vehicle body.

TROUBLESHOOTING HINTS (The most likely
causes for this code to be set are:)

•

Malfunction of the ignition switch.

•

Malfunction of the MFI relay.

•

Improper connector contact, open circuit or short-
circuited harness wire.

•

Disconnected ECM <M/T> or PCM <A/T> ground
wire.

•

Malfunction of the ECM <M/T> or PCM <A/T>.

DIAGNOSIS

STEP 1. Check connector A-21X at MFI relay for damage.
Q: Is the connector in good condition?

YES : Go to Step 2.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection (

P.00E-2

). Then confirm that

the malfunction symptom is eliminated.

AK000226

AK000226AB

CONNECTOR : A-21X

MFI RELAY

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-490

STEP 2. Check the MFI relay
(1) Remove the MFI relay.
(2) Check for continuity between the MFI relay terminals 2 and

4.

•

There should be continuity (approximately 70

Ω

)

(3) Use jumper wires to connect MFI relay terminal 4 to the

positive battery terminal and terminal 2 to the negative
battery terminal.

(4) Check the continuity between the MFI relay terminals 1 and

3 while connecting and disconnecting the jumper wire at
the negative battery terminal.

•

Should be less than 2 ohm.(Negative battery terminal
connected)

•

Should be open loop.(Negative battery terminal
disconnected)

(5) Install the MFI relay.

Q: Is the voltage normal?

YES : Go to Step 3.
NO : Replace the MFI relay. Then confirm that the

malfunction symptom is eliminated.

STEP 3. Check the power supply voltage at MFI relay
harness side connector A-21X.
(1) Disconnect the connector A-21X and measure at the

harness side.

(2) Measure the voltage between terminal 3, 4 and ground.

•

Voltage should be battery positive voltage.

Q: Is the voltage normal?

YES : Go to Step 4.
NO : Check harness connector C-07 at intermediate

connector for damage, and repair or replace as
required. Refer to, GROUP 00E, Harness Connector
Inspection (

P.00E-2

). If intermediate connector is in

good condition, repair harness wire between fusible
link (13) and MFI relay connector A-21X terminal 3, 4
because of open circuit. Then confirm that the
malfunction symptom is eliminated.

AK000226

AK000226AB

CONNECTOR : A-21X

MFI RELAY

AK000369AB

MFI RELAY SIDE
CONNECTOR

1 2
3 4

AK000370AB

MFI RELAY SIDE
CONNECTOR

1 2
3 4

AK000371AB

1

2

3

4

A-21X HARNESS
SIDE CONNECTOR