Mitsubishi Colt Ralliart. Manual - part 23

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-46

STEP 8. Check harness between A-121 (terminal 
No. 1) engine coolant temperature sensor 
connector and A-114 (terminal No. 14) 
engine-ECU connector or engine-CVT-ECU 
connector.

• Check output line for short circuit.

Q: Is the check result normal?

YES : 

Go to Step 9 .

NO : 

Repair the damaged harness wire.

STEP 9. M.U.T.-III data list

• Item 21: Engine coolant temperature sensor

OK:

Engine cold state: At ambient temperature 

(atmospheric temperature) or equivalent.

Engine hot state: At 80 

− 120 °C

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 <M/T> or 
engine-CVT-ECU <CVT>.

STEP 10. Perform resistance measurement at 
A-121 engine coolant temperature sensor 
connector.

• Disconnect connector, and measure at harness 

side.

• Ignition switch: ON

• Voltage between terminal No. 2 and earth.

OK: Continuity (2 

Ω or less)

Q: Is the check result normal?

YES : 

Go to Step 13 .

NO : 

Go to Step 11 .

AK402011

1

2

Connector: A-121

A-121 (B)

AD

A-121 Harness side 
connector

AK402745

6

4

2

5

3

1

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L

AD

A-114

Connector: 

A-114

Harness side connector

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

Battery

AK402011

1

2

Connector: A-121

A-121 (B)

AD

A-121 Harness side 
connector

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-47

STEP 11. Connector check: A-114 engine-ECU 
connector or engine-CVT-ECU connector

Q: Is the check result normal? 

YES : 

Go to Step 12 .

NO : 

Repair or replace the connector.

STEP 12. Check harness between A-121 (terminal 
No. 2) engine coolant temperature sensor 
connector and A-114 (terminal No. 29) 
engine-ECU connector or engine-CVT-ECU 
connector.

• Check earthing line for open circuit and damage.

Q: Is the check result normal?

YES : 

Go to Step 9 .

NO : 

Repair the damaged harness wire.

AK402745

6

4

2

5

3

1

9

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L

AD

A-114

Connector: 

A-114

Harness side connector

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

Battery

AK402011

1

2

Connector: A-121

A-121 (B)

AD

A-121 Harness side 
connector

AK402745

6

4

2

5

3

1

9

7

8

10

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63

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65

66

L

AD

A-114

Connector: 

A-114

Harness side connector

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

Battery

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-48

STEP 13. Perform voltage measurement at A-121 
engine coolant temperature sensor connector.

• Use special tool test harness (MB991709) to con-

nect connector, and measure at pick-up harness.

• Ignition switch: ON

• Voltage between terminal No. 1 and earth.

OK:

Engine coolant temperature at 

−20°C: 3.9 − 4.5 

V

Engine coolant temperature at 0

°C: 3.2 − 3.8 V

Engine coolant temperature at 20

°C: 2.3 − 2.9 V

Engine coolant temperature at 40

°C: 1.3 − 1.9 V

Engine coolant temperature at 60

°C: 0.7 − 1.3 V

Engine coolant temperature at 80

°C: 0.3 − 0.9 V

Q: Is the check result normal?

YES : 

Go to Step 9 .

NO : 

Go to Step 14 .

STEP 14. Connector check: A-114 engine-ECU 
connector or engine-CVT-ECU connector

Q: Is the check result normal?

YES : 

Go to Step 15 .

NO : 

Repair or replace the connector.

AK402011

1

2

Connector: A-121

A-121 (B)

AD

A-121 Harness side 
connector

AK402745

6

4

2

5

3

1

9

7

8

10

11

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61

62

63

64

65

66

L

AD

A-114

Connector: 

A-114

Harness side connector

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

Battery

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-49

STEP 15. Check harness between A-121 (terminal 
No. 1) engine coolant temperature sensor 
connector and A-114 (terminal No. 14) 
engine-ECU connector or engine-CVT-ECU 
connector.

• Check output line for damage.

Q: Is the check result normal?

YES : 

Go to Step 16 .

NO : 

Repair the damaged harness wire.

STEP 16. Connector check: A-114 engine-ECU 
connector or engine-CVT-ECU connector

Q: Is the check result normal?

YES : 

Check and repair harness between A-121 

(terminal No. 2) engine coolant temperature 
sensor connector and A-114 (terminal No. 
29) engine-ECU connector or 
engine-CVT-ECU connector.

• Check earthing line for damage.

NO : 

Repair or replace the connector.

AK402011

1

2

Connector: A-121

A-121 (B)

AD

A-121 Harness side 
connector

AK402745

6

4

2

5

3

1

9

7

8

10

11

12

13

14

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61

62

63

64

65

66

L

AD

A-114

Connector: 

A-114

Harness side connector

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

Battery

AK402745

6

4

2

5

3

1

9

7

8

10

11

12

13

14

15

16

17

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59

60

61

62

63

64

65

66

L

AD

A-114

Connector: 

A-114

Harness side connector

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

Battery

AK402011

1

2

Connector: A-121

A-121 (B)

AD

A-121 Harness side 
connector

Main

Index

Group

TOC