Mitsubishi Grandis. Manual — part 724

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-147

STEP 4. Connector check: B-15X engine control
relay connector and C-110 engine-ECU <M/T>
connector or engine-A/T-ECU <A/T> connector

Q: Is the check result normal?

YES :

Go to Step 5 .

NO :

Repair or replace.

STEP 5.Check harness between B-15X (terminal
No. 1) engine control relay connector and B-102
(terminal No. 1) No. 2 injector connector.

NOTE: Before checking harness, check intermediate
connector C-116, and repair if necessary.

• Check power supply line for damage.

Q: Is the check result normal?

YES :

Go to Step 6 .

NO :

Repair.

AK300967

2

1

3

4

AC

Harness side
connector

B-15X

Connector: B-15X

Relay box’s
triangle marks

AK305618AB

1

2

3

4

5

6

7

8

9

10

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12

13

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15

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18

19

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22

23

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25

26

27

Connector: C-110

<L.H. drive vehicles>

<R.H. drive vehicles>

C-110 (GR)

C-110 (GR)

Harness side connector

AK300967

2

1

3

4

AC

Harness side
connector

B-15X

Connector: B-15X

Relay box’s
triangle marks

AK300978

M

1

2

AK

B-102 (GR)

Harness side connector

Connector: B-102

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-148

STEP 6. Check harness between B-102 (terminal
No. 2) No. 2 injector connector and C-110
(terminal No. 5) engine-ECU <M/T> connector or
engine-A/T-ECU <A/T> connector

• Check output line for damage.

Q: Is the check result normal?

YES :

Go to Step 7 .

NO :

Repair.

STEP 7. Fuel pressure measurement.

• Fuel pressure measurement (Refer to Fuel

Pressure Test

P.13A-383

)

Q: Is the check result normal?

YES :

Go to Step 8 .

NO :

Repair.

STEP 8. Check the trouble symptoms.

Q: Does trouble symptom persist?

YES :

Replace engine-ECU <M/T> or

engine-A/T-ECU <A/T>.

NO :

Intermittent malfunction (Refer to GROUP
00

− How to Use

Troubleshooting/Inspection Service Points

P.00-5

).

Code No. P0303: No. 3 Cylinder Misfire Detected

OPERATION

• Refer to Code No. P0203 No. 3 Injector System

P.13A-125

.

FUNCTION

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

engine speed changes for an instant.

• The engine-ECU <M/T> or engine-A/T-ECU

<A/T> checks for such changes in engine speed.

TROUBLE JUDGMENT

Check Conditions

• Engine speed is 500 − 6,500 r/min.

• Engine coolant temperature is −10°C or higher.

• Barometric pressure is 76 kPa or higher.

• Volumetric efficiency is between 30% and 55 %.

• Adaptive learning is complete for the vane which

generates a crankshaft position signal.

AK300978

M

1

2

AK

B-102 (GR)

Harness side connector

Connector: B-102

AK305618AB

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

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19

20

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26

27

Connector: C-110

<L.H. drive vehicles>

<R.H. drive vehicles>

C-110 (GR)

C-110 (GR)

Harness side connector

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-149

• While the engine is running, excluding gear

shifting, deceleration, sudden
acceleration/deceleration and A/C compressor
switching.

• The throttle deviation is −0.06 V/10 ms to +0.06

V/10 ms.

Judgment Criteria (change in the angular

acceleration of the crankshaft is used for
misfire detection).

• Misfire has occurred more frequently than the

limit during the last 200 revolutions (when the
catalyst temperature has been 950

°C or higher).

or

• Misfire has occurred 15 times or more in the last

1,000 revolutions (that has been equivalent to
approximately 1.5 times the emission standard).

PROBABLE CAUSE

• Ignition system related part(s) failed

• Low compression pressure

• Failed engine-ECU <M/T>

• Failed engine-A/T-ECU <A/T>

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 26

P.13A-355

).

STEP 2. Connector check: B-104 No. 3 injector
connector

Q: Is the check result normal?

YES :

Go to Step 3 .

NO :

Repair or replace.

STEP 3. Check No. 3 injector itself.

• Check Injector itself (Refer to

P.13A-393

).

Q: Is the check result normal?

YES :

Go to Step 4 .

NO :

Replace No. 3 injector.

STEP 4. Connector check: B-15X engine control
relay connector and C-110 engine-ECU <M/T>
connector or engine-A/T-ECU <A/T> connector

Q: Is the check result normal?

YES :

Go to Step 5 .

NO :

Repair or replace.

AK300978

M

1

2

Connector: B-104

B-104 (GR)

AK300978AL

Harness side connector

AK300967

2

1

3

4

AC

Harness side
connector

B-15X

Connector: B-15X

Relay box’s
triangle marks

AK305618AB

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

Connector: C-110

<L.H. drive vehicles>

<R.H. drive vehicles>

C-110 (GR)

C-110 (GR)

Harness side connector

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-150

STEP 5.Check harness between B-15X (terminal
No. 1) engine control relay connector and B-104
(terminal No. 1) No. 3 injector connector.

NOTE: Before checking harness, check intermediate
connector C-116, and repair if necessary.

• Check power supply line for damage.

Q: Is the check result normal?

YES :

Go to Step 6 .

NO :

Repair.

STEP 6. Check harness between B-104 (terminal
No. 2) No. 3 injector connector and C-110
(terminal No. 14) engine-ECU <M/T> connector or
engine-A/T-ECU <A/T> connector

• Check output line for damage.

Q: Is the check result normal?

YES :

Go to Step 7 .

NO :

Repair.

STEP 7. Fuel pressure measurement.

• Fuel pressure measurement (Refer to Fuel

Pressure Test

P.13A-383

)

Q: Is the check result normal?

YES :

Go to Step 8 .

NO :

Repair.

STEP 8. Check the trouble symptoms.

Q: Does trouble symptom persist?

AK300967

2

1

3

4

AC

Harness side
connector

B-15X

Connector: B-15X

Relay box’s
triangle marks

AK300978

M

1

2

Connector: B-104

B-104 (GR)

AK300978AL

Harness side connector

AK300978

M

1

2

Connector: B-104

B-104 (GR)

AK300978AL

Harness side connector

AK305618AB

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

Connector: C-110

<L.H. drive vehicles>

<R.H. drive vehicles>

C-110 (GR)

C-110 (GR)

Harness side connector