Mitsubishi Colt Ralliart. Manual — part 700

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-125

Code No. P0300: Random/Multiple Cylinder Misfire Detected

OPERATION

• Refer to Code No. P0201: No. 1 injector system

P.13B-92

.

• Refer to Code No. P0202: No. 2 injector system

P.13B-97

.

• Refer to Code No. P0203: No. 3 injector system

P.13B-102

.

• Refer to Code No. P0204: No. 4 injector system

P.13B-107

.

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

• Engine speed is more than 500 r/min and is less

than 4,500 r/min.

• Engine coolant temperature is more than -10°C.

• Volume efficiency is more than 35%

• Adaptive learning is completed for the vane

which generates a crankshaft position signal.

• While the engine is running, excluding gear shift-

ing, deceleration, sudden acceleration/decelera-
tion and switching A/C compressor.

• When the variation in the throttle valve opening

angle is small.

Judgement Criterion

• Misfire occurred more frequently than the limit

during the last 200 revolutions

Or

• Misfire occurred more than the limit during the

last 1,000 revolutions

PROBABLE CAUSES

• Ignition system related part(s) failed

• Failed crank angle sensor

• Incorrect air-fuel ratio

• Low compression pressure

• Failed fuel system

• Failed engine coolant temperature sensor

• Skipping of timing belt teeth.

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1.M.U.T.-III data list

• Item No. 22: Crank angle sensor

OK: Keep the engine speed constant to make
the pulse width of output waveform con-
stant.

Q: Is the check result normal?

YES :

Go to Step 2 .

NO :

Check crank angle sensor system (Refer to
Code No. P0

P.13B-142

).

STEP 2. M.U.T.-III data list

• Refer to Data List Reference Table

P.13B-335

.

a. Item No. 21: Engine coolant temperature sensor
b. Item No. 81: Long-term fuel compensation

c. Item No. 82: Short-term fuel compensation

Q: Are the check results normal?

YES :

Go to Step 3 .

NO :

Perform the diagnosis code classified check
procedure for the sensor that has shown an
abnormal data valve (Refer to Inspection
Chart for Diagnosis Code

P.13B-18

).

STEP 3. Check ignition coil spark.

Q: Is the check result normal?

YES :

Go to Step 4 .

NO :

Check ignition circuit system (Refer to
Inspection Procedure 24

P.13B-327

).

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-126

STEP 4. Connector check: Injector connectors

a. A-102 (No. 1 injector connector)
b. A-103 (No. 2 injector connector)

c. A-104 (No. 3 injector connector)

d. A-105 (No. 4 injector connector)

Q: Are the check results normal?

YES :

Go to Step 5 .

NO :

Repair or replace the connector.

STEP 5. Check injector itself.

• Check Injector itself (Refer to

P.13B-367

).

Q: Is the check result normal?

YES :

Go to Step 6 .

NO :

Replace the injector.

STEP 6. Fuel pressure measurement.

• Fuel pressure measurement (Refer to Fuel Pres-

sure Test

P.13B-358

).

Q: Is the check result normal?

YES :

Go to Step 7 .

NO :

Repair the fuel pressure.

STEP 7. Check for intake of air from gaps in
gasket, seals, etc.

Q: Is the check result normal?

YES :

Go to Step 8 .

NO :

Repair for intake of air from gaps in gasket,
seals, etc.

STEP 8. Check for skipped timing belt teeth.

Q: Is the check result normal?

YES :

Go to Step 9 .

NO :

Repair for skipped timing chain teeth.

STEP 9. M.U.T.-III diagnosis code.

• Reconfirmation of diagnosis code.

Q: Is the diagnosis code set?

YES :

Replace engine-ECU.

NO :

Intermittent malfunction (Refer to GROUP
00

− How to Use Troubleshooting/Inspection

Service Points

− How to Cope with

Intermittent Malfunctions

P.00-13

).

Code No. P0301: No. 1 Cylinder Misfire Detected

OPERATION

• Refer to Code No. P0201: No. 1 Injector System

P.13B-92

.

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

• Engine speed is more than 500 r/min and is less

than 4,500 r/min.

• Engine coolant temperature is more than -10°C.

• Volume efficiency is more than 35%

• Adaptive learning is completed for the vane

which generates a crankshaft position signal.

• While the engine is running, excluding gear shift-

ing, deceleration, sudden acceleration/decelera-
tion and switching A/C compressor.

• When the variation in the throttle valve opening

angle is small.

Judgement Criterion

• Misfire occurred more frequently than the limit

during the last 200 revolutions

Or

• Misfire occurred more than the limit during the

last 1,000 revolutions

PROBABLE CAUSES

• Ignition system related part(s) failed

• Low compression pressure

• Failed fuel system

• Failed engine-ECU

AK600602

M

1

2

AB

A-102 (G)

A-103 (G)

A-105 (G)

A-104 (G)

Connector: A-102, A-103, A-104, A-105

Harness side
connector

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-127

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.13B-327

).

STEP 2. Connector check: A-102 No. 1 injector
connector

Q: Is the check result normal?

YES :

Go to Step 3 .

NO :

Repair or replace the connector.

STEP 3. Check No. 1 injector itself.

• Check Injector itself (Refer to

P.13B-367

).

Q: Is the check result normal?

YES :

Go to Step 4 .

NO :

Replace the No. 1 injector.

STEP 4. Connector check: B-106 engine control
relay connector and A-114 engine-ECU
connector

Q: Is the check result normal?

YES :

Go to Step 5 .

NO :

Repair or replace the connector.

AK402088

M

1

2

AC

A-102(G)

Connector: A-102

Harness side
connector

3

2

1

4

AK402084

J/B side
connector

B-106

Connector: B-106
J/B (front side)

AC

AK402745

6

4

2

5

3

1

9

7

8

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

L

AF

A-114

Connector:

A-114

Harness side connector

Engine-ECU

Battery

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-128

STEP 5. Check harness between B-106 (terminal
No. 4) engine control relay connector and A-102
(terminal No. 1) No. 1 injector connector.

NOTE: Before checking harness, check intermediate
connector A-17 and B-112, and repair if necessary.

• Check power supply line for damage.

Q: Is the check result normal?

YES :

Go to Step 6 .

NO :

Repair the damaged harness wire.

STEP 6. Check harness between A-102 (terminal
No. 2) No. 1 injector connector and A-114
(terminal No. 8) engine-ECU connector

• Check earthing line for damage.

Q: Is the check result normal?

YES :

Go to Step 7 .

NO :

Repair the damaged harness wire.

STEP 7. Fuel pressure measurement.

• Fuel pressure measurement (Refer to Fuel Pres-

sure Test

P.13B-358

).

Q: Is the check result normal?

YES :

Go to Step 8

NO :

Repair the fuel pressure.

3

2

1

4

AK402084

J/B side
connector

B-106

Connector: B-106
J/B (front side)

AC

AK402088

M

1

2

AC

A-102(G)

Connector: A-102

Harness side
connector

AK402088

M

1

2

AC

A-102(G)

Connector: A-102

Harness side
connector

AK402745

6

4

2

5

3

1

9

7

8

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

L

AF

A-114

Connector:

A-114

Harness side connector

Engine-ECU

Battery

Main

Index

Group

TOC