Mitsubishi Lancer Evolution IX. Manual - part 657

TROUBLESHOOTING

ENGINE COOLING

14-13

STEP 5. Check the harness wire between 
engine-ECU connector C-121 and fan controller 
connector A-17.
NOTE: 

AC210877AC

Connector: A-13 <LHD>

A-13 (B)

AC310903AB

Connector: C-31 <RHD>

C-31

If intermediate connector A-13 <LHD> terminal 2 and 
intermediate connector C-31 <RHD> terminal 14 is 
damaged, repair or replace it. Refer to GROUP 00, 
How to Use Troubleshooting/Inspection Service 
Points 

P.00-5

.

AC505254 AC

Connector: C-121 <LHD>

C-121 (GR)

Engine-ECU

15
29

2221

23
3534

7

8

16

18

19

17

20

31

32

33

30

5

6

11 10

12

13

14

26

2827

25

3

4

2

9

24

1

JAE

Component side

AC505255 AC

Connector: C-121 <RHD>

C-121 (GR)

Engine-ECU

15
29

2221

23
3534

7

8

16

18

19

17

20

31

32

33

30

5

6

11 10

12

13

14

26

2827

25

3

4

2

9

24

1

JAE

Component side

AC210859

Connector: A-17

A-17 (GR)

AD

Fan controller

Component side

Q: Are the harness wires between engine-ECU 

connector C-121 terminal 18 and fan controller 
connector A-17 terminal 2 damaged?
YES : 

Repair or replace them, then go to Step 8.

NO : 

Go to Step 6.

TROUBLESHOOTING

ENGINE COOLING

14-14

STEP 6. Check the fan controller at engine-ECU 
connector C-121.

AC505254

16

25

10

24

1
9

2

4

27

13

26

11

3

12

2829

1415

3031

1718

33

32

6

20

5

19

21

35

34

8

23

7

22

JAE

AB

Connector: C-121 <LHD>

Harness side

C-121 (GR)

Engine-ECU

AC505255

16

25

10

24

1
9

2

4

27

13

26

11

3

12

2829

1415

3031

1718

33

32

6

20

5

19

21

35

34

8

23

7

22

JAE

AB

Connector: C-121 <RHD>

Harness side

C-121 (GR)

Engine-ECU

(1) Do not disconnect engine-ECU connector C-121.
(2) Pull out terminal No.18.
(3) Turn the ignition switch to the "ON" position.

Q: Does the cooling fan motor operate?

YES : 

Replace the engine-ECU. Then go to Step 

8.

NO : 

Go to Step 7.

STEP 7. Check the fan controller at engine-ECU 
connector C-121.

AC505254

16

25

10

24

1
9

2

4

27

13

26

11

3

12

2829

1415

3031

1718

33

32

6

20

5

19

21

35

34

8

23

7

22

JAE

AB

Connector: C-121 <LHD>

Harness side

C-121 (GR)

Engine-ECU

AC505255

16

25

10

24

1
9

2

4

27

13

26

11

3

12

2829

1415

3031

1718

33

32

6

20

5

19

21

35

34

8

23

7

22

JAE

AB

Connector: C-121 <RHD>

Harness side

C-121 (GR)

Engine-ECU

(1) Disconnect engine-ECU connector C-121.
(2) Pull out terminal No.18.
(3) Connect terminal No.18 to the body earth.
(4) Turn the ignition switch to the "ON" position.

Q: Does the cooling fan motor stop running?

YES : 

Replace the engine-ECU. Then go to Step 

8.

NO : 

Replace the fan controller. Then go to Step 
8.

STEP 8. Check the symptoms.

Q: Does the cooling fan operate correctly?

YES : 

The procedure is complete.

NO : 

Return to Step 1.

ON-VEHICLE SERVICE

ENGINE COOLING

14-15

ON-VEHICLE SERVICE

ENGINE COOLANT LEAK CHECK

M1141001000388

WARNING

When pressure testing the cooling system, 
slowly release cooling system pressure to 
avoid getting burned by hot coolant.

CAUTION

• Be sure to completely clean away any mois-

ture from the places checked.

• When the tester is taken out, be careful not to 

spill any coolant.

•

ACX01844 AB

Cap adapter

Adapter

Be careful when installing and removing the 
tester and when testing not to deform the 
filler neck of the radiator.

1. Check that the coolant level is up to the filler neck. 

Install a radiator tester and apply 160 kPa 
pressure, and then check for leakage from the 
radiator hose or connections.

2. If there is leakage, repair or replace the 

appropriate part.

RADIATOR CAP PRESSURE CHECK

M1141001300453

NOTE: Be sure that the cap is clean before testing. 
Rust or other foreign material on the cap seal will 
cause an improper reading.

AC211643 AB

Cap adapter

1. Use a cap adapter to attach the cap to the tester.
2. Increase the pressure until the indicator of the 

gauge stops moving.

Minimum limit: 83 kPa
Standard value: 93 

− 123 kPa

3. Replace the radiator cap if the reading does not 

remain at or above the minimum limit.

ENGINE COOLANT REPLACEMENT

M1141001200553

1. Remove the under cover (Refer to GROUP 51, 

Front Bumper 

P.51-2

).

WARNING

When removing the radiator cap, use care to 
avoid contact with hot coolant or steam. 
Place a shop towel over the cap and turn the 
cap anti-clockwise a little to let the pressure 
escape through the vinyl tube. After relieving 
the steam pressure, remove the cap by 
slowly turning it anti-clockwise.

2. Drain the water from the radiator, heater core and 

engine after unplugging the radiator drain plug 
and removing the radiator cap.

AC210639AB

44 ± 5 N·m

Water inlet pipe

3. Drain the water in the water jacket by unplugging 

the drain plug of the cylinder block.

4. Remove the reserve tank and drain the coolant.
5. Drain the cooling water then clean the path of the 

cooling water by injecting water into the radiator 
from the radiator cap area.

ON-VEHICLE SERVICE

ENGINE COOLING

14-16

6. Apply the designated sealant to the screw area of 

the cylinder block drain plug, and then tighten to 
the standard torque.
Specified sealant: 3M Nut Locking Part 

No.4171 or equivalent

Tightening torque: 44 

± 5 N⋅m

7. Securely tighten the drain plug of the radiator.
8. Assemble the reserve tank.

CAUTION

Do not use alcohol or methanol anti-freeze or any 
engine coolants mixed with alcohol or methanol 
anti-freeze. The use of an improper anti-freeze 
can cause corrosion of the aluminium compo-
nents.

AC210658AB

MB991871

Air hose

9. By referring to the section on coolant, select an 

appropriate concentration for safe operating 
temperature within the range of 30 to 60 %. Use 
special tool LLC changer (MB991871) to refill the 
coolant. A convenient mixture is a 50 % water and 
50 % antifreeze solution (freezing point: 

−31°C).

Recommended antifreeze: DIA QUEEN SUPER 

LONG LIFE COOLANT or equivalent

Quantity: 6.0 L
NOTE: For how to use the special tool, refer to its 
manufacturer’s instructions.

10.Reinstall the radiator cap.
11.Start the engine and let it warm up until the 

thermostat opens.

12.Repeatedly revving the engine up to 3,000 r/min 

several times, then stop the engine.

13.Remove the radiator cap after the engine has 

become cold, and pour in coolant up to the brim. 
Reinstall the cap.

CAUTION

Do not overfill the reserve tank.
14.Add coolant to the reserve tank between the 

"FULL" and "LOW" mark if necessary.

15.Install the under cover (Refer to GROUP 51, 

Front Bumper 

P.51-2

).

CONCENTRATION MEASUREMENT

M1141001100448

Measure the temperature and specific gravity of the 
engine coolant to check the antifreeze concentration.

Standard value: 30 

− 60 % (allowable concen-

tration range)

Recommended antifreeze: DIA QUEEN SUPER 

LONG LIFE COOLANT or equivalent

CAUTION

If the concentration of the anti-freeze is below 30 
%, the anti-corrosion property will be adversely 
affected. In addition, if the concentration is 
above 60 %, both the anti-freezing and engine 
cooling properties will decrease, affecting the 
engine adversely. For these reasons, be sure to 
maintain the concentration level within the speci-
fied range.

FAN CONTROLLER CHECK

M1141006100238

1. Remove the centre under cover (Refer to GROUP 

51, Front Bumper 

P.51-2

).

AC210945AB

2

3

1

Fan controller
connector: 
Component 
side

Fan controller

2. Disconnect the fan controller connector.
3. Turn the ignition switch to the "ON" position, and 

measure the voltage between the harness-side 
connector terminals.

Standard value: Battery positive voltage

4. Turn the ignition switch to the "LOCK" (OFF) 

position, and connect the fan controller connector.