Mitsubishi Galant 9G. Manual - part 657

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-70

STEP 5. Check for open circuit between mass airflow
sensor connector B-10 (terminal No. 4) and PCM connector
B-21 (terminal No. 69).
Q: Is the harness wire in good condition?

YES : Go to Step 6.
NO : Repair it. Then go to Step 8.

AK303805

CONNECTOR: B-10

B-10 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE

AK303018

54 53 52 51

62 61 60 59 58

69 68 67 66 65 64

75 74 73 72 71

82 81 80 79 78 77

CONNECTOR: B-21

PCM

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER

B-21 (B)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-71

STEP 6. Using scan tool MB991958, check data list item 12:
Mass 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, Mass Airflow Sensor.

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

°C

to 95

°C (176°F to 203°F).

• The standard value during idling should be between 2.0

and 6.0 g/sec.

• When the engine is revved, the mass airflow rate 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

− How to

Cope with Intermittent Malfunctions

P.00-14

NO : Replace the PCM. Then go to Step 8.

STEP 7. Check harness connector B-21 at PCM for
damage.
Q: Is the harness connector in good condition?

YES : Replace the mass airflow sensor. Then go to Step 8.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 8.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

AK303018

54 53 52 51

62 61 60 59 58

69 68 67 66 65 64

75 74 73 72 71

82 81 80 79 78 77

CONNECTOR: B-21

PCM

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER

B-21 (B)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-72

STEP 8. 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 P0103 set?

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

DTC P0106: Manifold Absolute Pressure Circuit Range/Performance Problem

53 54 55 56

58 59 60 61 62

64 65 66 67 68 69

71 72 73 74 75

77 78 79 80 81 82

100

93 94 95

96 97 98

101 102 103 104

105 106 107 108

109 110 111 112 113

AK400877

GREEN-YELLO

BLUE-RED

BLA

POWERTRAIN CONTROL
MODULE (PCM)

MANIFOLD ABSOLUTE
PRESSURE SENSOR

Manifold Absolute Pressure Sensor Circuit

102

B-21

B-22

B-02

(MU802723)

5 V

AK303808AB

CONNECTOR: B-02

MANIFOLD
ABSOLUTE
PRESSURE
SENSOR

B-02 (B)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-73

CIRCUIT OPERATION

• A 5-volt voltage is supplied to the manifold abso-

lute pressure sensor power terminal (terminal No.
3) from the PCM (terminal No. 68). The ground
terminal (terminal No. 2) is grounded with PCM
(terminal No. 69).

• A voltage that is proportional to the intake mani-

fold pressure is sent to the PCM (terminal No.
102) from the manifold absolute pressure sensor
output terminal (terminal No. 1).

TECHNICAL DESCRIPTION

• The manifold absolute pressure sensor outputs a

voltage which corresponds to the intake manifold
pressure.

• The PCM checks whether this voltage is within a

specified range.

DESCRIPTIONS OF MONITOR METHODS

Compare load value with manifold absolute pressure

sensor output voltage.

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)

• Engine coolant temperature sensor

• Throttle position sensor

• Mass airflow sensor

• Intake air temperature sensor

• Barometric pressure sensor

AK303013

CONNECTORS: B-21, B-22

PCM

AIR CLEANER

B-22 (B)

B-21 (B)

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