Mitsubishi Galant (2004+). Manual - part 924

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-513

STEP 6. Using scan tool MB991958, check data list item 14: 
Throttle Position Sensor (sub).

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) Turn the ignition switch to the "ON" position.
(3) Detach the intake air hose at the throttle body.
(4) Disconnect the connector of the throttle position sensor.
(5) Use test harness special tool (MB991658) to connect only 

terminals No. 3, No. 4, No. 5, and No. 6.

(6) Set scan tool MB991958 to the data reading mode for item 

14, Throttle Position Sensor (sub).

• Output voltage should be between 2.2 and 2.8 volts 

when the throttle valve is fully closed with your finger.

• Output voltage should be 4.0 volts or more when the 

throttle valve is fully open with your finger.

(7) 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 :  Replace the PCM. Then go to Step 8. 

STEP 7. Replace the throttle body assembly.

(1) Replace the throttle body assembly.
(2) Turn the ignition switch to the "ON" position.

(3) After the DTC has been deleted, read the DTC again.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC P0223 set?

YES : Replace the PCM. Then go to Step 8.
NO :  The inspection is complete.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

AK303818

1

6 5 4 3 2

AB

CONNECTOR: B-06

B-06 (B)

HARNESS 
CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-514

STEP 8. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).

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) Turn the ignition switch to the "ON" position.
(3) After the DTC has been deleted, read the DTC again.
(4) Turn the ignition switch to the "LOCK"(OFF) position.
Q: Is DTC P0223 set?

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

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-515

DTC P0300: Random/Multiple Cylinder Misfire Detected

CAUTION

If DTC P0300 has been set, TCL related DTC 
U1120 is also set. After P0300 has been diag-
nosed, don't forget to erase DTC U1120.

.

TECHNICAL DESCRIPTION

• If a misfire occurs while the engine is running, the 

engine speed changes for an instant.

• The PCM checks for such changes in engine 

speed.

.

DESCRIPTIONS OF MONITOR METHODS
Monitor angular acceleration of crankshaft and 

detect malfunction when negative variation of the 
angular acceleration is large.

.

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)

• Camshaft position sensor

• Mass airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

• Barometric pressure sensor

• Throttle position sensor

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-516

DTC SET CONDITIONS

Logic Flow Chart

Check Conditions

• Engine speed is between 500 and 6,500 r/min.

• Engine coolant temperature is higher than −10°C 

(14

°F).

• Barometric pressure is higher than 76 kPa (22.4 

in.Hg).

• Volumetric efficiency is between 30 and 55 per-

cent.

• Adaptive learning is complete for the vane which 

generates a crankshaft position signal.

• While the engine is running, excluding gear shift-

ing, deceleration, sudden acceleration/decelera-
tion and A/C compressor switching.

• The throttle deviation is −0.6 V/10 ms to +0.6 

V/10 ms.

START

MONITORING

CONDITIONS

CALCULATE CRANKSHAFT

ANGULAR ACCELERATION (A

N

)

A

N

 < TH

MF

 (Ne,   v)

MISFIRE

CALCULATE PERCENT MISFIRE (R

MF

)

END

NO

NO

NO

NO

NO

NO

YES

YES

YES

YES

YES

YES

GOOD

WITHIN 1000rev

R

MF

 > SPECIFIED VALUE

MALFUNCTION

(EXCEED STD  ×1.5)

GOOD

MALFUNCTION

(CATALYTIC CONVERTER

IS DAMAGED.) 

GOOD

R

MF

 > TH

CD

 (Ne,   v)

CALCULATE PERCENT MISFIRE (R

MF

)

WITHIN 200rev

Ne: ENGINE SPEED
   v: VOLUMETRIC EFFICIENCY

AK302033