Mitsubishi Colt Ralliart. Manual — part 695

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-105

STEP 7. Check harness between B-106 (terminal
No. 4) engine control relay connector and A-104
(terminal No. 1) injector connector.

NOTE: Before checking harness, check intermediate
connectors A-17 and B-112, and repair if necessary.

• Check power supply line for damage.

Q: Is the check result normal?

YES :

Go to Step 8 .

NO :

Repair.

STEP 8. Connector check: A-114 engine-ECU
connector

Q: Is the check result normal?

YES :

Go to Step 9 .

NO :

Repair or replace.

3

2

1

4

AK402084

J/B side
connector

B-106

Connector: B-106
J/B (front side)

AC

AK402090

M

1

2

A-104(G)

AC

Connector: A-104

Harness side
connector

AK402745

6

4

2

5

3

1

9

7

8

10

11

12

13

14

15

16

17

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49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

L

AF

A-114

Connector:

A-114

Harness side connector

Engine-ECU

Battery

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-106

STEP 9. Check harness between A-104 (terminal
No. 2) injector connector and A-114 (terminal No.
23) engine-ECU connector.

• Check output line for open/short circuit and dam-

age.

Q: Is the check result normal?

YES :

Go to Step 10 .

NO :

Repair.

STEP 10. Perform signal wave pattern
measurement at A-114 engine-ECU connector
(using an oscilloscope).

• Disconnect engine-ECU connector, and connect

special tool power plant ECU check harness
(MB991987) and measure the voltage on the
check connector.

• Engine: Idling

• Transmission: Neutral

• Voltage between terminal No. 23 and earth.

OK: Waveform as shown in Inspection Pro-
cedure with Oscilloscope (Refer to

P.13B-352

) should be displayed.

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.

AK402090

M

1

2

A-104(G)

AC

Connector: A-104

Harness side
connector

AK402745

6

4

2

5

3

1

9

7

8

10

11

12

13

14

15

16

17

18

19

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46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

L

AF

A-114

Connector:

A-114

Harness side connector

Engine-ECU

Battery

AK402745

6

4

2

5

3

1

9

7

8

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

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30

31

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47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

L

AF

A-114

Connector:

A-114

Harness side connector

Engine-ECU

Battery

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-107

Code No. P0204: No. 4 Injector System

OPERATION

• Power is supplied to the injector (terminal No. 1)

through the engine control relay (terminal No. 4).

• The engine-ECU (terminal No. 24) turns on the

power transistor in the unit to activate the injector
(terminal No. 2).

AK402684

2

1

3

1

2

4

19

21

20

18

17

16

15

14

1213

11

8 9

L

10

37
52 53 54 555657585960616263646566

38 39 404142434445464748495051

22 23 24 252627282930313233343536

7

5

3

1

6

4

2

A-114

AQ

B-106

A-17

B-112

B-108

Engine
control
relay

Injector
No. 4

A-105

(MU802062)

4

6

4

1

2

2

24

No. 4 Injector Circuit

R

R

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

L

3

1

1

1

R

Fusible link

16

20A

J/B

To engine-ECU

Engine-ECU

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-108

FUNCTION

• The engine-ECU controls the injector activation

time.

• The fuel injection amount from the injector

depends on the injector activation time.

TROUBLE JUDGEMENT

Check Conditions

• Engine speed is more than 50 r/min and is less

than 1,000 r/min.

• Throttle position sensor (main) output voltage is

less than 1.0 V.

• Not during fuel cut or forced injector-driving (actu-

ator test)

Judgement Criterion

• Injector coil surge voltage (battery voltage plus 2

V) is not detected for 4 seconds.

PROBABLE CAUSES

• Failed No. 4 injector

• Open/short circuit or damage in No. 4 injector cir-

cuit, or loose connector contact

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III actuator test

• Item 04: No. 4 injector

Idling state varies.

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-105 injector
connector

Q: Is the check result normal?

YES :

Go to Step 3 .

NO :

Repair or replace.

STEP 3. Perform resistance measurement at
A-105 injector connector.

• Disconnect connector, and measure at injector

side.

• Resistance between terminals No. 1 and No. 2.

OK: 10.5

− 13.5 Ω (at 20°C)

Q: Is the check result normal?

YES :

Go to Step 4 .

NO :

Replace No. 4 injector.

STEP 4. Perform voltage measurement at A-105
injector connector.

• Disconnect connector and measure at harness

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 .

AK402091

M

1

2

A-105(G)

AC

Connector: A-105

Harness side
connector

AK402091

M

1

2

A-105(G)

AC

Connector: A-105

Harness side
connector

AK402091

M

1

2

A-105(G)

AC

Connector: A-105

Harness side
connector

Main

Index

Group

TOC