Mitsubishi Eclipse. Manual — part 138

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-45

STEP 1. Using scan tool MB991958, check data list item 12:
Volume Airflow Sensor.

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Start the engine and run at idle.
(3) Set scan tool MB991958 to the data reading mode for item

12, Volume Airflow Sensor.

(4) Warm-up the engine to normal operating temperature: 80

°C

to 96

°C (176°F to 205°F).

• The standard value during idling should be 10 Hz or

more.

• When the engine is revved, the frequency should

increase according to the increase in engine speed.

(5) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : It can be assumed that this malfunction is intermittent.

Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

P.00-6

.

NO : Go to Step 2.

STEP 2. Measure the power supply voltage at volume
airflow sensor connector B-14 by backprobing.
(1) Do not disconnect the connector B-14.
(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 4 and ground by

backprobing.

• Voltage should be battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is battery positive voltage (approximately 12 volts)

present?
YES : Go to Step 5.
NO : Go to Step 3.

AK300810

AB

MB991911

16-PIN

MB991827

MB991824

AK300078

3

4

5

1

2

6

7

CONNECTOR: B-14

AB

B-14 (B)

HARNESS
CONNECTOR:
COMPONENT SIDE

AKX01514 AH

1 2 3 4 5 6 7

B-14 HARNESS
CONNECTOR:
HARNESS SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-46

STEP 3. Measure the power supply voltage at volume
airflow sensor harness side connector B-14.
(1) Disconnect the connector B-14 and measure at the harness

side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 4 and ground.

• Voltage should be battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is battery positive voltage (approximately 12 volts)

present?
YES : Go to Step 4.
NO : Repair harness wire between MFI relay connector

A-18X (terminal No. 4) and volume airflow sensor
connector B-14 (terminal No. 4) because of open
circuit or short circuit to ground. Then go to Step 13.

STEP 4. Check connector B-14 at the volume airflow
sensor for damage.
Q: Is the connector in good condition?

YES : Repair harness wire between MFI relay connector

A-18X (terminal No. 4) and volume airflow sensor
connector B-14 (terminal No. 4) because of harness
damage. Then go to Step 13.

NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 13.

STEP 5. Check connector B-14 at volume airflow sensor
for damage.
Q: Is the connector in good condition?

YES : Go to Step 6.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 13.

AK300078

3

4

5

1

2

6

7

CONNECTOR: B-14

AB

B-14 (B)

HARNESS
CONNECTOR:
COMPONENT SIDE

AKX01405

B-14 HARNESS CONNECTOR:
COMPONENT SIDE

7 6 5 4 3 2 1

AL

AK300078

3

4

5

1

2

6

7

CONNECTOR: B-14

AB

B-14 (B)

HARNESS
CONNECTOR:
COMPONENT SIDE

AK300078

3

4

5

1

2

6

7

CONNECTOR: B-14

AB

B-14 (B)

HARNESS
CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-47

STEP 6. Measure the sensor supply voltage at volume
airflow sensor harness side connector B-14.
(1) Disconnect the connector B-14 and measure at the harness

side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 3 and ground.

• Voltage should be between 4.8 and 5.2 volts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.8 and 5.2 volts?

YES : Go to Step 9.
NO : Go to Step 7.

AK300078

3

4

5

1

2

6

7

CONNECTOR: B-14

AB

B-14 (B)

HARNESS
CONNECTOR:
COMPONENT SIDE

AKX01406 AG

7 6 5 4 3 2 1

B-14 HARNESS
CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-48

STEP 7. Check connector C-60 at ECM <M/T> or connector
C-54 at PCM <A/T> for damage.
Q: Is the harness connector in good condition?

YES : Go to Step 8.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 13.

AK300415

82

78

8180

89

90

91

92

79

87

71

74 73 72

76 75

77

85

88

83

84

86

CONNECTOR: C-60 <M/T>

AB

C-60 (G)

HARNESS CONNECTOR:
COMPONENT SIDE

AK300412

42

43

48

49

50

51

52

53

54

55

56

57

46 45 44

58

59

60

61

62

63

64

65

66

47

41

C-54 (GR)

CONNECTOR: C-54 <A/T>

AB

HARNESS CONNECTOR:
COMPONENT SIDE