Mitsubishi Outlander (2003+). Manual - part 38

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MFI)

13A-15

OPERATION

œ

Power is supplied to the air flow sensor (terminal 
No. 4) from the engine control relay (terminal No. 
1) and earthed to the engine-ECU (terminal No. 
40) from the air flow sensor (terminal No. 5).

œ

A power voltage of 5 V is applied to the air flow 
sensor output terminal (terminal No. 3) from the 
engine-ECU (terminal No. 90).

œ

An air flow sensor filter reset signal is inputted to 
the air flow sensor (terminal No. 7) from the 
engine-ECU (terminal No. 19).

FUNCTION

œ

Air flow sensor outputs a pulse signal propor-
tional to the intake air flow rate.

œ

The engine-ECU determines the basic injection 
timing of the injector using the pulse signal output 
from the air flow sensor and the engine speed 
signal.

œ

When the throttle position sensor output is low, 
the engine-ECU causes the power transistor in 
the unit to be ON to send an air flow sensor filter 
reset signal to the air flow sensor. In response to 
the reset signal, the air flow sensor resets the fil-
ter circuit to improve the ability of the air flow sen-
sor to measure the air flow rate in the area where 
the intake air flow rate is low.

TROUBLE JUDGMENT

Check Condition

œ

Engine speed is 500 r/min or more.

Judgment Criterion

œ

Sensor output frequency of 3.3 Hz or less for 2 
seconds.

PROBABLE CAUSE

œ

Failed air flow sensor

œ

Open/short circuit in air flow sensor circuit or 
loose connector contact

œ

Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. MUT-II data list

œ

Refer to Data list reference table 

3

13A



.

a. Item 12: Air flow sensor

Q: Is the check result normal?

YES : 

Intermittent malfunction (Refer to GROUP 

00 

-

 How to Use 

Troubleshooting/Inspection Service Points 

3

00



).

NO : 

Go to Step 2 .

STEP 2. Connector check: B-08 air flow sensor 
connector

Q: Is the check result normal?

YES : 

Go to Step 3 .

NO : 

Repair.

STEP 3. Measure voltage at B-08 air flow sensor 
connector.

œ

Disconnect connector, and measure at harness 
side.

œ

Ignition switch: ON

œ

Voltage between terminal No. 3 and earth.

OK: 4.9 

-

 5.1 V

Q: Is the check result normal?

YES : 

Go to Step 9 .

NO : 

Go to Step 4 .

AK300253

3

4

5

1

2

6

7

AB

Harness side connector

B-08 (B)

Connector: B-08

AK300253

3

4

5

1

2

6

7

AB

Harness side connector

B-08 (B)

Connector: B-08

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MFI)

13A-16

STEP 4. Measure voltage at C-137 engine-ECU 
connector.

œ

Measure engine-ECU terminal voltage.

œ

Ignition switch: ON

œ

Voltage between terminal No. 90 and earth.

OK: 4.9 

-

 5.1 V

Q: Is the check result normal?

YES : 

Go to Step 5 .

NO : 

Go to Step 6 .

STEP 5. Connector check: C-137 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Check and repair harness between B-08 

(terminal No. 3) air flow sensor connector 
and C-137 (terminal No. 90) engine-ECU 
connector.

œ

Check output line for open circuit.

NO : 

Repair.

AK300254

82

78

8180

89

90

91

92

79

87

71

74 73 72

76 75

77

85

88

83

84

86

AB

CONNECTOR: C-137

C-137

Harness side connector

AK300254

82

78

8180

89

90

91

92

79

87

71

74 73 72

76 75

77

85

88

83

84

86

AB

CONNECTOR: C-137

C-137

Harness side connector

AK300253

3

4

5

1

2

6

7

AB

Harness side connector

B-08 (B)

Connector: B-08

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MFI)

13A-17

STEP 6. Connector check: C-137 engine-ECU 
connector.

Q: Is the check result normal?

YES : 

Go to Step 7 .

NO : 

Repair.

STEP 7. Check harness between B-08 (terminal 
No. 3) air flow sensor connector and C-137 
(terminal No. 90) engine-ECU connector.

œ

Check output line for short circuit.

Q: Is the check result normal?

YES : 

Go to Step 8 .

NO : 

Repair.

STEP 8. MUT-II data list

œ

Refer to Data list reference table 

3

13A



.

a. Item 12: Air flow sensor

Q: Is the check result normal?

YES : 

Intermittent malfunction (Refer to GROUP 

00 

-

 How to Use 

Troubleshooting/Inspection Service Points 

3

00



).

NO : 

Replace engine-ECU.

AK300254

82

78

8180

89

90

91

92

79

87

71

74 73 72

76 75

77

85

88

83

84

86

AB

CONNECTOR: C-137

C-137

Harness side connector

AK300253

3

4

5

1

2

6

7

AB

Harness side connector

B-08 (B)

Connector: B-08

AK300254

82

78

8180

89

90

91

92

79

87

71

74 73 72

76 75

77

85

88

83

84

86

AB

CONNECTOR: C-137

C-137

Harness side connector

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MFI)

13A-18

STEP 9. Measure voltage at B-08 air flow sensor 
connector.

œ

Disconnect connector, and measure at harness 
side.

œ

Ignition switch: ON

œ

Voltage between terminal No. 4 and earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 11 .

NO : 

Go to Step 10 .

STEP 10. Connector check: B-17X engine control 
relay connector

Q: Is the check result normal?

YES : 

Check and repair harness between B-08 

(terminal No. 4) air flow sensor connector 
and B-17X (terminal No.1) engine control 
relay connector.

œ

Check power supply line for 
open/short circuit.

NO : 

Repair.

STEP 11. Check at B-08 air flow sensor 
connector.

œ

Disconnect and measure at harness side.

œ

Resistance between terminal No. 5 and earth.

OK: 2 

W

 or less

Q: Is the check result normal?

YES : 

Go to Step 14 .

NO : 

Go to Step 12 .

AK300253

3

4

5

1

2

6

7

AB

Harness side connector

B-08 (B)

Connector: B-08

AK300255

2

1

3

4

Relay box’s
triangle marks

AB

CONNECTOR: B-17X

B-17X

Harness side
connector

AK300253

3

4

5

1

2

6

7

AB

Harness side connector

B-08 (B)

Connector: B-08

AK300253

3

4

5

1

2

6

7

AB

Harness side connector

B-08 (B)

Connector: B-08