Mitsubishi Lancer Evolution IX. Manual - part 416

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-139

STEP 11. Fuel pressure measurement.

• Fuel pressure measurement (Refer to fuel pres-

sure test 

P.13A-396

).

Q: Is the check result normal?

YES : 

Go to Step 12 .

NO : 

Repair.

STEP 12. Check for intake of air from intake hose 
and inlet manifold.

Q: Is the check result normal?

YES : 

Go to Step 13 .

NO : 

Repair.

STEP 13. Check for skipped timing belt teeth.

Q: Is the check result normal?

YES : 

Go to Step 14 .

NO : 

Repair.

STEP 14. Exhaust gas recirculation system 
check.

• Exhaust gas recirculation system check (Refer to 

GROUP 17 

− Exhaust gas recirculation (EGR) 

system 

P.17-14

).

Q: Is the check result normal?

YES : 

Replace the engine-ECU

NO : 

Repair.

Code No. P0301: No. 1 Cylinder Misfire Detection System

OPERATION

• Refer to P0201 injector circuit 

P.13A-105

.

FUNCTION

• If a misfire occurs while the engine is running, the 

engine speed changes for an instant.

• The engine-ECU checks for such changes in 

engine speed.

TROUBLE JUDGMENT

Check Conditions

• The engine speed is 500 − 6,500 r/min.

• The engine coolant temperature is −10°C or 

higher.

• The barometric pressure is 76 kPa or more.

• The volumetric efficiency is 30 − 55%.

• The adaptive learning has been completed with 

the vane that generates the crankshaft position 
signals.

• During the engine operation except the shift 

change or low speed driving and rapid accelera-
tion and deceleration, also intermittent operation 
of air compressor (A/C: within the 3 seconds after 
changing to ON from OFF or to OFF from ON).

• The throttle deviation is within the range of −0.06 

V/10ms to 0.06 V/10ms.

Judgment Criteria

• Misfire has occurred more frequently than 

allowed during the last 200 revolutions (When the 
catalyst temperature is higher than 950

°C).

or

• Misfire has occurred in 15 or more of the last 

1,000 revolutions (corresponding to 1.5 times the 
limit of emission standard).

PROBABLE CAUSES

• Ignition system related part(s) failed

• Low compression pressure

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check ignition coil spark. 

Q: Is the check result normal?

YES : 

Go to Step 2 .

NO : 

Check ignition Circuit System (Refer to 
Inspection procedure 30 <L.H. drive 
vehicles>

P.13A-356

 or Inspection 

procedure 31 <R.H. drive 
vehicles>

P.13A-363

).

STEP 2. Connector check: B-22 No. 1 injector 
connector

Q: Is the check result normal?

YES : 

Go to Step 3 .

NO : 

Repair or replace the connector.

AK305012

1

2

Connector : B-22

Harness side connector

B-22(B)

AC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-140

STEP 3. Check No. 1 injector itself.

• Check Injector itself (Refer to 

P.13A-406

).

Q: Is the check result normal?

YES : 

Go to Step 4 .

NO : 

Replace the No. 1 injector.

STEP 4. Connector check: C-121 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Go to Step 5 .

NO : 

Repair or replace the connector.

STEP 5. Check harness between B-22 (terminal 
No. 2) No. 1 injector connector and C-121 
(terminal No. 1) engine-ECU connector

• Check output line for damage.

Q: Is the check result normal?

YES : 

Go to Step 6 .

NO : 

Repair the damaged harness wire.

STEP 6. Check injector resistor itself.

• Check injector resistor itself (Refer to 

P.13A-407

).

Q: Is the check result normal?

YES : 

Go to Step 7 .

NO : 

Replace the injector resistor.

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-22

Harness side connector

B-22(B)

AC

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-141

STEP 7. Connector check: B-119 injector resistor 
connector and C-121 engine-ECU connector

Q: Is the check result normal?

YES : 

Go to Step 8 .

NO : 

Repair or replace the connector.

STEP 8. Check harness between B-119 (terminal 
No. 1) injector resistor connector and B-22 
(terminal No. 1) No.1 injector connector.

Q: Is the check result normal?

YES : 

Go to Step 9 .

NO : 

Repair the damaged harness wire.

STEP 9. Fuel pressure measurement.

• Fuel pressure measurement (Refer to fuel pres-

sure test 

P.13A-396

).

Q: Is the check result normal?

YES : 

Replace the engine-ECU.

NO : 

Repair.

AK305016

1

2

3

4

5

6

AB

Harness side 
connector

B-119(B)

B-119(B)

Connector : B-119

<L.H.drive vehicles>

<R.H.drive vehicles>

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>

AK305016

1

2

3

4

5

6

AB

Harness side 
connector

B-119(B)

B-119(B)

Connector : B-119

<L.H.drive vehicles>

<R.H.drive vehicles>

AK305012

1

2

Connector : B-22

Harness side connector

B-22(B)

AC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-142

Code No. P0302: No. 2 Cylinder Misfire Detection System

OPERATION

• Refer to P0202 injector circuit 

P.13A-111

.

FUNCTION

• If a misfire occurs while the engine is running, the 

engine speed changes for an instant.

• The engine-ECU checks for such changes in 

engine speed.

TROUBLE JUDGMENT

Check Conditions

• The engine speed is 500 − 6,500 r/min.

• The engine coolant temperature is −10°C or 

higher.

• The barometric pressure is 76 kPa or more.

• The volumetric efficiency is 30 − 55%.

• The adaptive learning has been completed with 

the vane that generates the crankshaft position 
signals.

• During the engine operation except the shift 

change or low speed driving and rapid accelera-
tion and deceleration, also intermittent operation 
of air compressor (A/C: within the 3 seconds after 
changing to ON from OFF or to OFF from ON).

• The throttle deviation is within the range of −0.06 

V/10ms to 0.06 V/10ms.

Judgment Criteria

• Misfire has occurred more frequently than 

allowed during the last 200 revolutions (When the 
catalyst temperature is higher than 950

°C).

or

• Misfire has occurred in 15 or more of the last 

1,000 revolutions (corresponding to 1.5 times the 
limit of emission standard).

PROBABLE CAUSES

• Ignition system related part(s) failed

• Low compression pressure

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check ignition coil spark. 

Q: Is the check result normal?

YES : 

Go to Step 2 .

NO : 

Check ignition circuit system (Refer to 
Inspection procedure 30 <L.H. drive 
vehicles>

P.13A-356

 or Inspection 

procedure 31 <R.H. drive 
vehicles>

P.13A-363

).

STEP 2. Connector check: B-20 No. 2 injector 
connector

Q: Is the check result normal?

YES : 

Go to Step 3 .

NO : 

Repair or replace the connector.

STEP 3. Check No. 2 injector itself.

• Check Injector itself (Refer to 

P.13A-406

).

Q: Is the check result normal?

YES : 

Go to Step 4 .

NO : 

Replace the No. 2 injector.

AK305012

1

2

Connector : B-20

Harness side connector

B-20(B)

AD