Mitsubishi Lancer Evolution IX. Manual - part 413

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-127

STEP 10. Connector check: C-121 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Go to Step 11 .

NO : 

Repair or replace the connector.

STEP 11. Check harness between B-17 (terminal 
No. 2) No. 4 injector connector and C-121 
(terminal No. 2) engine-ECU connector.

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

age.

Q: Is the check result normal? 

YES : 

Go to Step 12 .

NO : 

Repair the damaged harness wire.

AK501995

2

3

4

5

6

7

8

9

11

12

13

14

15

16

17

18

19

20

30

21

22

23

24

25

26

27

28

29

31

32

33

34

35

1

10

AB

Connector: C-121

C-121 (GR)

C-121 (GR)

Harness side connector

<L. H. drive vehicles>

<R. H. drive vehicles>

AK305012

1

2

Connector : B-17

Harness side connector

B-17(B)

AF

AK501995

2

3

4

5

6

7

8

9

11

12

13

14

15

16

17

18

19

20

30

21

22

23

24

25

26

27

28

29

31

32

33

34

35

1

10

AB

Connector: C-121

C-121 (GR)

C-121 (GR)

Harness side connector

<L. H. drive vehicles>

<R. H. drive vehicles>

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-128

STEP 12. Perform signal wave pattern 
measurement at C-121 engine-ECU connector 
(Using an oscilloscope).

• Engine: Idling

• Transmission: Neutral

• Voltage between terminal No. 2 and earth.

OK: Waveform should be display on Inspec-
tion procedure using an oscilloscope (Refer 
to 

P.13A-385

).

Q: Is the check result normal? 

YES : 

Intermittent malfunction (Refer to GROUP 

00 

− How to Use 

Troubleshooting/Inspection Service Points 

P.00-5

).

NO : 

Replace the engine-ECU.

AK501995

2

3

4

5

6

7

8

9

11

12

13

14

15

16

17

18

19

20

30

21

22

23

24

25

26

27

28

29

31

32

33

34

35

1

10

AB

Connector: C-121

C-121 (GR)

C-121 (GR)

Harness side connector

<L. H. drive vehicles>

<R. H. drive vehicles>

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-129

Code No. P0234: Turbocharger Wastegate System Malfunction

FUNCTION

• The engine-ECU checks that the engine is not 

overcharged by always monitoring intake air vol-
ume.

• The engine-ECU protects the engine by shutting 

off fuel when an overcharged condition is 
detected.

TROUBLE JUDGMENT

Check Condition

• Waste gate solenoid valve is normal.

Judgment Criterion

• The volumetric efficiency continues to be the sta-

tus having more than the specified valve for the 
stipulated period.

PROBABLE CAUSES

• Failed turbocharger wastages actuator

• Failed supercharging pressure control system

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check turbocharger supercharging 
pressure.

• Check turbocharger supercharging pressure 

(Refer to GROUP 15 

− On-vehicle Service − Tur-

bocharger Supercharging Pressure 

P.15-2

).

Q: Is the check result normal?

YES : 

Go to Step 2 .

NO : 

Repair or replace.

STEP 2. Check supercharging pressure control 
system.

• Check supercharging pressure control system 

(Refer to GROUP 15 

− On-vehicle Service − 

Supercharging Pressure Control System 

P.15-3

).

Q: Is the check result normal?

YES : 

Go to Step 3 .

NO : 

Repair or replace.

STEP 3. M.U.T.-II/III diagnosis code.

• Reconfirmation of diagnosis code.

Q: Is the diagnosis code?

YES : 

Replace the engine-ECU.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use 

Troubleshooting/Inspection Service Points 

P.00-5

).

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-130

Code No. P0243: Waste Gate Solenoid Valve System

OPERATION

• Power is supplied from the engine control relay 

(terminal No. 4) to the waste gate solenoid valve 
(terminal No. 1).

• The engine-ECU (terminal No. 41) causes the 

power transistor in the unit to be ON to supply 
power to the waste gate solenoid valve (terminal 
No. 2).

FUNCTION

• In response to a signal from the engine-ECU, the 

waste gate solenoid valve controls the turbo 
charge pressure to be introduced into the waste 
gate actuator of the turbo charger.

TROUBLE JUDGMENT

Check Condition

• Battery voltage is 10 V or more.

AK501810

2

1

1

2

3

4

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

Battery

B-26

Waste gate solenoid valve

4

1

2

3

1

2

41

Engine-ECU

Waste gate solenoid valve circuit

B-12X

C-119

(MU801824)

B-Y

B-Y

B-Y

R-Y

LG

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  PU: Purple

AB

NOTE

*1: L.H. drive vehicles
*2: R.H. drive vehicles

6 <A-13> (*1) or
13 <C-31> (*2)

Engine control relay

To engine-ECU