Mitsubishi Galant 9G. Manual - part 1092

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-668

STEP 5. 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 3 − 

Catalytic Converter Monitor 

P.13B-6

.

(2) Read the diagnostic trouble code.
Q: Is DTC P0431 set?

YES : Replace the left bank side catalytic converter. Then 

go to Step 6.

NO :  The inspection is complete.

STEP 6. 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 3 − 

Catalytic Converter Monitor 

P.13B-6

.

(2) Read the diagnostic trouble code.
Q: Is DTC P0431 set?

YES : Replace the PCM. Then go to Step 7.
NO :  The inspection is complete.

STEP 7. 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 3 − 

Catalytic Converter Monitor 

P.13B-6

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0431 set?

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

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-669

DTC P0441: Evaporative Emission Control System Incorrect Purge Flow

.

TECHNICAL DESCRIPTION

• PCM detects stuck open condition of evaporative 

emission purge solenoid valve and stuck closed 
condition of evaporative emission ventilation 
solenoid valve by pressure change in fuel tank.

• Stuck open evaporative emission purge solenoid 

valve is judged through monitoring leak of evapo-
rative emission system.

• Stuck closed evaporative emission ventilation 

solenoid valve is judged after 20 seconds from 
end of monitoring leak of evaporative emission 
system, or of usual operation of evaporative 
emission purge solenoid from ON to OFF.

.

DESCRIPTIONS OF MONITOR METHODS

Fuel tank pressure decreases largely during 

purge-cut.

.

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)

• Fuel tank pressure sensor monitor

Sensor (The sensor below is determined to be 

normal)

• Not applicable

.

AK303026

EVAPORATIVE
EMISSION PURGE
SOLENOID

CONNECTOR: B-05

B-05 (B)

AB

AK303146

CONNECTOR: F-08

AB

EVAPORATIVE
EMISSION
VENTILATION
SOLENOID

EVAPORATIVE
EMISSION
CANISTER

F-08 (B)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-670

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• ON duty cycle of the evaporative emission purge 

solenoid is 0 percent.

• Engine is running.

• 20 seconds have elapsed since the duty cycle of 

the evaporative emission purge solenoid has 
turned to 0 percent.

Judgment Criteria

• The pressure in the fuel tank is −2 kPa (−0.59 

in.Hg) or less for 0.1 second.

.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function 

− OBD-II Drive Cycle − 

Procedure 1 

− Evaporative Emission System 

Leak Monitor 

P.13B-6

.

.

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

• Evaporative emission purge solenoid failed.

• Evaporative emission ventilation solenoid failed.

• Fuel tank differential pressure sensor circuit 

related part(s) failed.

START

END

NO

NO

NO

NO

YES

YES

YES

NO

MALFUNCTION

GOOD

CONTINUOUS

FAILURE FOR 100msecs

MONITORING CONDITIONS FOR

MALFUNCTION DETECTION

AK302406

FUEL-TANK PRESSURE

< -2kPa (-0.59 in.Hg)

MONITORING CONDITIONS FOR

PASS JUDGEMENT?

REVERTING PRESSURE

 DETECTED DURING

EVAP MONITOR?

YES

YES

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-671

DIAGNOSIS

Required Special Tools:

• MB991958: Scan tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

STEP 1. 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) Read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC P0451 set?

YES : Refer to DTC P0451 - Evaporative Emission Control 

System Pressure Sensor Range/Performance 

P.13B-733

.

NO :  Go to Step 2. 

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827