Mitsubishi L200. Manual — part 61

TROUBLESHOOTING

DIESEL FUEL

13A-40

FUNCTION

• The variable geometry control solenoid valve

controls the vacuum pressure introduced into the
variable geometry actuator, using the signal from
the engine-ECU. This allows the boost pressure
to be adequate for the driving conditions.

TROUBLE JUDGMENT

Check Conditions

• Battery positive voltage is 8 − 16 V.

• 2 seconds later after the engine has started up.

Judgment Criterion

• Variable geometry control solenoid valve output

voltage is 4.5 V or more (driving current is abnor-
mally high).

PROBABLE CAUSES

• Short circuit in variable geometry control solenoid

valve circuit or loose connector contact

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: A-56 variable
geometry control solenoid valve connector, C-
105 engine-ECU connector

Q: Are the check results normal?

YES :

Go to Step 2 .

NO :

Repair or replace the connector.

AK900982

2 1

AC

A-56 (BR)

Harness side
connector

Connector: A-56

AKA00089

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

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

43

44

45

46

47

48

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

C-105 (B)

C-105 (B)

<R.H. drive vehicles>

Harness side connector

<L.H. drive vehicles>

Connector: C-105

AB

TROUBLESHOOTING

DIESEL FUEL

13A-41

STEP 2. Check harness between A-56 (terminal
No. 1) variable geometry control solenoid valve
connector and C-105 (terminal No. 17) engine-
ECU connector.

• Check output line for short circuit.

Q: Is the check result normal?

YES :

Go to Step 3 .

NO :

Repair the damaged harness wire.

STEP 3. M.U.T.-III diagnosis code

• Reconfirmation of diagnosis code.

Q: Is diagnosis code set?

YES :

Replace the engine-ECU. When the engine-

ECU is replaced, write the chassis number
(Refer to GROUP 00

− Precautions Before

Service

− How to Perform Chassis Number

Writing ). After replacing the engine-ECU,
register the injector identification code and
learn fuel injection (Refer to GROUP 00

−

Precautions Before Service

− What The

Common Rail Engine Learns ). After
registering the injector identification code,
carry out the forcible DPF regeneration.
(Refer to GROUP 17

− Emission Control −

Diesel Particulate Filter (DPF) System

−

Forcible DPF Regeneration ).

NO :

Intermittent malfunction (Refer to GROUP
00

− How to Use Troubleshooting/

Inspection Service Points

− How to Cope

with Intermittent Malfunctions ).

AK900982

2 1

AC

A-56 (BR)

Harness side
connector

Connector: A-56

AKA00089

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

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

43

44

45

46

47

48

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

C-105 (B)

C-105 (B)

<R.H. drive vehicles>

Harness side connector

<L.H. drive vehicles>

Connector: C-105

AB

TROUBLESHOOTING

DIESEL FUEL

13A-42

Code No. P0072: Intake Air Temperature Sensor No. 1 Circuit Low Input <Euro5>

OPERATION

• A power voltage of 5 V is applied to the intake air

temperature sensor No. 1 output terminal (termi-
nal No. 2) from the engine-ECU (terminal No. 62).

• The power voltage is earthed to the engine-ECU

(terminal No. 86) from the intake air temperature
sensor No. 1 (terminal No. 1).

FUNCTION

• The intake air temperature sensor No. 1 converts

the intake air temperature into a voltage and
inputs the voltage signal to the engine-ECU.

• In response to the signal, the engine-ECU cor-

rects the fuel injection amount, etc.

• The intake air temperature sensor No. 1 is a kind

of resistor, which has characteristics to reduce its
resistance as the intake air temperature rises.
Therefore, the sensor output voltage varies with
the intake air temperature, and becomes lower as
the intake air temperature rises.

TROUBLE JUDGMENT

Check Conditions

• Battery positive voltage is 8 − 16 V

• 2 seconds later after the ignition switch has been

in "ON" position or the engine has started up.

Judgment Criterion

• The intake air temperature sensor No. 1 output

voltage is 0.09 V or less for 0.5 second.

PROBABLE CAUSES

• Failed intake air temperature sensor No. 1

• Short circuit or harness damage in intake air tem-

perature sensor No.1 circuit or loose connector
contact

• Failed engine-ECU

AKA00356

1

2

3

4

5 6 7 8 9

10 1112 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

49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72

43 44 45 46 47 48

73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96

5

4

3

2

1

86

62

Intake air temperature
sensor No. 1 (integrated in
air flow sensor)

Engine-ECU

1

2

Intake Air Temperature Sensor No. 1 Circuit

B-L

Y-L

A-135

C-105

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 SI: Silver

5 V

AB

TROUBLESHOOTING

DIESEL FUEL

13A-43

DIAGNOSIS PROCEDURE

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

• Item 43: Intake air temperature sensor No. 1

OK: At ambient temperature (atmospheric
temperature) or equivalent.

Q: Is the check result normal?

YES :

Intermittent malfunction (Refer to GROUP

00

− How to Use Troubleshooting/

Inspection Service Points

− How to Cope

with Intermittent Malfunctions ).

NO :

Go to Step 2 .

STEP 2. Connector check: A-135 air flow sensor
connector

Q: Is the check result normal?

YES :

Go to Step 3 .

NO :

Repair or replace the connector.

STEP 3. Check intake air temperature sensor No.
1 itself.

• Check intake air temperature sensor No. 1 itself

(Refer to

P.13A-595

).

Q: Is the check result normal?

YES :

Go to Step 4 .

NO :

Replace the air flow sensor.

STEP 4. Perform Voltage measurement at A-135
air flow sensor connector.

• Disconnect connector, and measure at harness

side.

• Ignition switch: ON

• Voltage between terminal No. 2 and earth.

OK: 4.5

− 4.9 V

Q: Is the check result normal?

YES :

Go to Step 8 .

NO :

Go to Step 5 .

STEP 5. Connector check: C-105 engine-ECU
connector

Q: Is the check result normal?

YES :

Go to Step 6 .

NO :

Repair or replace the connector.

AKA00399

AB

Harness side
connector

A-135 (B)

Connector: A-135

AKA00399

AB

Harness side
connector

A-135 (B)

Connector: A-135

AKA00089

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

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

43

44

45

46

47

48

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

C-105 (B)

C-105 (B)

<R.H. drive vehicles>

Harness side connector

<L.H. drive vehicles>

Connector: C-105

AB