Mitsubishi Galant 9G. Manual — part 653

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-54

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-6

.

(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.

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-6

.

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

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

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-55

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

AK400876

RED

WHITE-GREEN

BLA

C

K

RED-

WHITE

RED-

WHITE

B-10

B-17X

MFI RELAY

BATTERY

MASS AIRFLOW
SENSOR

HEAT
SENSITIZING
RESISTANCE

POWERTRAIN CONTROL
MODULE (PCM)

108

3

69

2

1

2

4

4

3

Mass Airflow Sensor Circuit

B-21

B-22

TO PCM

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-56

.

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

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-57

DTC SET CONDITIONS

Logic Flow Chart

Check Conditions

• 3 seconds or more have passed since the ignition

switch was turned to "ON" position.

Judgement Criteria

• Mass airflow sensor output voltage has continued

to be lower than 0.2 volt for 2 seconds.

.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function

− OBD-II Drive Cycle −

Procedure 6

− Other Monitor

P.13A-6

.

.

TROUBLESHOOTING HINTS (The most
likely causes for this code to be set are:)

• Mass airflow sensor failed.

• Open or shorted mass airflow sensor circuit, or

connector damage.

• PCM failed.

END

MALFUNCTION

YES

YES

YES

NO

NO

NO

CONTINUOUS

FAILURE FOR 2secs

OUTPUT VOLTAGE

< 0.2V

OUTPUT VOLTAGE

> 4.9V

MONITORING

CONDITIONS

GOOD

START

AK302008

YES

NO