Mitsubishi Galant (2004+). Manual - part 1240

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-653

TECHNICAL DESCRIPTION

• The PCM monitors the Evaporative Emission 

(EVAP) System pressure.

• The PCM controls the evaporative emission ven-

tilation solenoid. It closes the evaporative emis-
sion ventilation solenoid to seal the evaporative 
emission canister side of the system.

• The evaporative emission purge solenoid is 

opened to allow manifold vacuum to create low 
pressure (vacuum) in the EVAP system.

• When the EVAP system develops a vacuum of 2 

kPa (0.29 psi), the evaporative emission purge 
solenoid is closed and the fuel system vacuum is 
maintained at 2 kPa. (0.29 psi).

• The PCM determines whether there is a leak in 

the EVAP system by monitoring the vacuum 
inside the fuel tank.

• The test is stopped when fuel vapor pressure 

exceeds predetermined limits.

.

DESCRIPTIONS OF MONITOR METHODS

• Measure reverting pressure after depressurizing 

by intake manifold negative pressure and detect 
malfunction if reverting pressure rises largely.

.

MONITOR EXECUTION

• Once per driving cycle.

.

MONITOR EXECUTION CONDITIONS (Other 
Monitor and Sensor)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• Evaporative emission purge solenoid monitor

• Evaporative emission purge system monitor

• Fuel tank differential pressure sensor monitor

• Evaporative emission ventilation solenoid monitor

• Fuel level sensor monitor

• Fuel temperature sensor monitor

 Sensor (The sensors below are determined to be 

normal)

• Mass airflow sensor

• Barometric pressure sensor

• Intake air temperature sensor

• Engine coolant temperature sensor

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-654

LOGIC FLOW CHARTS (Monitor Sequence)

.

DTC SET CONDITIONS
Remaining fuel amount is 15 

− 40 percent of capacity 

(fuel level sensor output signal voltage is 1.4 

− 2.4 

volts).

Check Conditions A: At Start up

• Intake air temperature is 36°C (97°F) or less 

when the engine is started.

• The engine coolant temperature is 36 °C (97 °F) 

or less when the engine is started.

AC306649

0.04in, 0.02in GROSS LEAK MONITOR

START

YES

YES

YES

YES

YES

NO

NO

NO

NO

NO

MONITORING
CONDITIONS?

DEPRESSURIZE FUEL TANK PRESSURE

GROSS LEAK

MONITORING CONDITIONS

SHUT PURGE LINE

MEASURE REVERTING
PRESSURE :    PFT

PFT > PT

SPECIFIED TIMES

MONITORED

MALFUNCTION

END

SPECIFIED TIMES

HAVE PASSED

MALFUNCTION

(GROSS LEAK)

GOOD

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-655

Check Conditions B: For Test to Run

• The fuel tank temperature is less than 36 °C (97 

°F), and less than 13 minutes have elapsed since 
the engine was started.

• Engine coolant temperature is greater than 60°C 

(140

°F).

• Power steering pressure switch: "OFF"

• Barometric pressure is greater than 76 kPa (11 

psi).

• Fuel tank differential pressure sensor output volt-

age is 1 to 4 volts.

• Vehicle speed is greater than or equal to 20 km/h 

(12.4 mph).

Check Conditions C: For Test to Stop

• Intake air temperature is greater than −10°C 

(14

°F).

• When the evaporative emission purge solenoid 

and evaporative emission ventilation solenoid are 
closed, the pressure in the fuel tank is less than 
451 Pa (0.065 psi).

• The pressure fluctuation is less than 647 Pa 

(0.094 psi).

• 10 seconds have elapsed since the start of the 

previous monitoring.

• Monitoring time: 75 − 125 seconds.

Judgment Criteria

• Internal pressure of the fuel tank has changed 

more than 977 Pa (0.142 psi) in 20 seconds after 
the tank and vapor line were closed.
NOTE: The monitoring time (75 

−

 125 seconds) 

depends on the fuel level and the temperature in 
the fuel tank.
The next monitoring occurs at least 10 seconds 
later.

.

DTC SET CONDITIONS
Remaining fuel amount is 40 

− 85 percent of capacity 

(fuel level sensor output voltage is 2.4 

− 3.7 volts).

Check Conditions A: At Start up

• Intake air temperature is less than 36 °C (97 °F) 

when the engine is started.

• The engine coolant temperature is less than 36 

°C (97 °F) when the engine is started.

Check Conditions B: For Test to Run

• The fuel tank temperature is less than 36 °C (97 

°F).

• Barometric pressure is greater than 76 kPa (11 

psi).

• Fuel tank differential pressure sensor output volt-

age is 1 to 4 volts.

Check Conditions C: For Test to Stop

• Intake air temperature is greater than −10 °C 

(14

°F).

• Engine coolant temperature is greater than 20 °C 

(68 

°F).

• When the evaporative emission purge solenoid 

and evaporative emission ventilation solenoid are 
closed, the pressure in the fuel tank is less than 
451 Pa (0.065 psi).

• 10 seconds have elapsed since the start of the 

previous monitoring.

• Monitoring time: 10 − 14 minutes.

Judgment Criteria

• Internal pressure of the fuel tank has changed 

more than 2 kPa (0.29 psi) in 128 seconds after 
the tank and vapor line were closed.
NOTE: The monitoring time (10 

−

 14 minutes) 

depends on the fuel level and the temperature in 
the fuel tank.
The next monitoring occurs at least 10 seconds 
later.

.

OBD-ll DRIVE CYCLE PATTERN
Refer to Diagnostic Function 

− OBD-ll Drive Cycle − 

Procedure 1 

− Evaporative Emission System Leak 

Monitor 

P.13B-5

.

.

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

• Loose fuel cap.

• Fuel cap relief pressure is incorrect.

• Evaporative emission canister seal is leaking.

• Fuel tank, purge line or vapor line seal is leaking.

• Evaporative emission ventilation solenoid does 

not seal.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-656

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A

STEP 1. Using scan tool MB991958, check the evaporative 
emission system monitor test.

CAUTION

• To prevent damage to scan tool MB991958, always turn 

the ignition switch to the "LOCK" (OFF) position before 
connecting or disconnecting scan tool MB991958.

• During this test, the PCM will automatically increase 

the engine speed to 1,600 r/min or greater. Check that 
the transaxle is set to the "P" position.

(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.

(3) Erase the DTCs using scan tool MB991958.
(4) Check that the fuel cap is securely closed (Tighten until 

three clicks are heard). 

(5) Start the engine.
(6) Select "System Test."
(7) Select "Evap Leak Mon."
(8) During this test, keep the accelerator pedal at the idle 

position.

(9) Keep the engine speed and engine load within the specified 

range. When the monitor test starts, the "In Progress" item 
on scan tool MB991958 will change from "NO" to "YES."

(10) Turn the ignition switch to the "LOCK" (OFF) position, and 

disconnect scan tool MB991958.

Q: Is "Evap Leak Mon. Completed. Test Failed and DTCs 

Set" displayed on scan tool MB991958?
YES : A malfunction has been detected during the monitor 

test. Refer to the Diagnostic Trouble Code Chart and 
diagnose any other DTCs that are set 

P.13B-33

. If no 

other DTC's have been set, go to Step 2.

NO <"Evap Leak Mon. Completed. Test Passed" is 
displayed on scan tool MB991958.> : The evaporative 

emission system is working properly at this time. 
Explain to the customer that an improperly tightened 
fuel cap can cause the MIL to illuminate. Return the 
vehicle to the customer.

NO <"Evap Leak Mon. Discontinued. Retest again from 
the first" is displayed on scan tool MB991958.> : The 

EVAP monitor has been interrupted during the test. 
Turn the ignition switch to the "LOCK" (OFF) position 
once, and repeat the monitoring from Step 1.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827