Mitsubishi Galant (2004+). Manual - part 808

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-49

STEP 7. Check for harness damage between mass airflow 
sensor connector B-10 (terminal No. 3) and PCM connector 
B-22 (terminal No. 108).
Q: Is the harness wire in good condition?

YES : Go to Step 8.
NO :  Repair it. Then go to Step 9.

STEP 8. Replace the mass airflow sensor.
(1) Replace the mass airflow sensor.
(2) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− OBD-II Drive Cycle − Procedure 6 − 

Other Monitor 

P.13A-5

.

(3) Check the diagnostic trouble code (DTC).
Q: Is DTC P0101 set?

YES : Replace the PCM. Then go to Step 9.
NO :  The inspection is complete.

AK303805

2

1

3

4

AB

CONNECTOR: B-10

B-10 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE

AK303016

104

96

94

95

93 92 91

99 98 97

103 102 101 100

108 107 106 105

113 112 111 110 109

CONNECTOR: B-22

B-22 (B)

PCM

AB

HARNESS CONNECTOR: 
COMPONENT SIDE

AIR CLEANER

AK303805

2

1

3

4

AB

CONNECTOR: B-10

B-10 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-50

STEP 9. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− OBD-II Drive Cycle − Procedure 6 − 

Other Monitor 

P.13A-5

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0101 set?

YES : Retry the troubleshooting.
NO :  The inspection is complete.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-51

DTC P0102: Mass Airflow Circuit Low Input

CAUTION

If DTC P0102 has been set, TCL related DTC 
U1120 is also set. After P0102 has been diag-
nosed, don't forget to erase DTC U1120.

1

2

3

4

1

2

3 4

52

51

53 54 55 56

57

58 59 60 61 62

63

64 65 66 67 68 69

70

71 72 73 74 75

76

77 78 79 80 81 82

83

100

99

92

91

93 94 95

96 97 98

101 102 103 104

105 106 107 108

109 110 111 112 113

AK303801

RED

WHITE-GREEN

BLA

CK

RED-
WHITE

RED-

WHITE

B-10

B-17X

MFI 
RELAY

BATTERY

MASS AIRFLOW 
SENSOR

HET 
SENSITIZING
RESISTANCE

POWERTRAIN CONTROL 
MODULE (PCM)

108

3

69

2

1

2

4

4

3

Mass Airflow Sensor Circuit

B-21

B-22

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-52

.

CIRCUIT OPERATION

• The mass airflow sensor power is supplied from 

the MFI relay (terminal No. 4), and the ground is 
provided on the PCM (terminal No. 69).

• A voltage that is according to the mass airflow 

rate is sent to the PCM (terminal No. 108) from 
the mass airflow sensor output terminal (terminal 
No. 3).

.

TECHNICAL DESCRIPTION

• While the engine is running, the mass airflow 

sensor outputs voltage which corresponds to the 
mass airflow rate.

• The PCM checks whether the voltage output by 

the mass airflow sensor while the engine is run-
ning is within a specified range.

.

DESCRIPTIONS OF MONITOR METHODS
Mass airflow sensor output voltage is out of specified 

range.

.

MONITOR EXECUTION
Continuous

.

MONITOR EXECUTION CONDITIONS (Other 
monitor and Sensor)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• Not applicable

Sensor (The sensor below is determined to be 

normal)

• Not applicable

.

AK303802AB

CONNECTOR: B-10

MASS AIRFLOW SENSOR
(WITH BUILT-IN INTAKE AIR 
TEMPERATURE SENSOR)

B-10 (GR)

AK303013

CONNECTORS: B-21, B-22

PCM

AB

AIR CLEANER

B-22 (B)

B-21 (B)

AK303803AB

CONNECTOR: B-17X

MFI RELAY

B-17X