Mitsubishi Galant (2004+). Manual — part 973

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-709

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TECHNICAL DESCRIPTION

• The fuel tank may be under a slight pressure or

vacuum depending on the state of the Evapora-
tive Emission (EVAP) System. The PCM monitors
and responds to these pressure/vacuum
changes. If the pressure/vacuum varies from the
specified range, the PCM will set DTC P0455.

• The PCM energizes the evaporative emission

ventilation solenoid to shut off the evaporative
emission canister outlet port.

• The evaporative emission purge solenoid is acti-

vated to apply engine manifold vacuum to the
EVAP system.

• When the fuel system develops a vacuum of 2

kPa (0.29 psi), the evaporative emission purge
solenoid is turned "off" and the fuel system vac-
uum is maintained at 2 kPa (0.29 psi).

• The PCM determines whether there is a leak or

clog in the fuel system by measuring the change
in vacuum inside the fuel tank.

• The test is stopped when fuel vapor pressure is

determined to be too high.

.

DESCRIPTIONS OF MONITOR METHODS

• Depressurizing EVAP system by intake manifold

negative pressure is impossible within specified
period.

.

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

.

AC305053AC

EVAPORATIVE EMISSION
VENTILATION SOLENOID

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-710

LOGIC FLOW CHARTS (Monitor Sequence)

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DTC SET CONDITIONS

Check Conditions A: At Start up

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

upon engine start up.

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

less upon engine start up.

Check Conditions B: For Test to Run

• The engine coolant temperature is 60°C (140°F)

or greater and the fuel tank is 15

− 40 percent full.

• The engine coolant temperature is 20°C (68°F) or

greater and the fuel tank is 40

− 85 percent full.

• The engine speed is greater than or equal to

1,600 r/min.

• Barometric pressure is greater than 76 kPa (11

psi).

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

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-711

• Volumetric efficiency is between 20 and 70 per-

cent.

• The fuel tank temperature is 36°C (97°F) or less.

• The fuel tank differential pressure sensor output

voltage is 1

− 4 volts.

Check Conditions C: For Test to Stop

• The intake air temperature is greater than 5°C

(41

°F).

• When the evaporative emission purge solenoid

and evaporative emission ventilation solenoid are
closed, the pressure in the fuel tank rises to 451
Pa (0.065 psi) or less and the amount of remain-
ing fuel is 15

− 40 percent of capacity upon

engine start-up.

• When the evaporative emission purge solenoid

and evaporative emission ventilation solenoid are
closed, the pressure in the fuel tank rises to 324
Pa (0.047 psi) or less and the amount of remain-
ing fuel is 40

− 85 percent of capacity upon

engine start-up.

• 10 seconds have elapsed from the start of the

previous monitoring.

• Monitoring time: 150 seconds.

Judgment Criteria

• The fuel tank internal pressure is 2 kPa (0.29 psi)

or more after the evaporative emission purge
solenoid valve has been driven when the fuel
tank and vapor line were closed.

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OBD-ll DRIVE CYCLE PATTERN
Refer to Diagnostic Function

− OBD-ll Drive Cycle −

Procedure 1

− Evaporative Emission System Leak

Monitor

P.13A-5

.

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

• Loose fuel cap.

• Fuel cap relief pressure is incorrect.

• Fuel overflow limiter valve failed.

• Purge line or vapor line is clogged.

• Fuel tank, purge line or vapor line seal failed.

• Evaporative emission purge solenoid valve failed.

• Evaporative emission ventilation solenoid valve

failed.

• Fuel tank differential pressure sensor failed.

• Evaporative emission canister seal is faulty.

• Evaporative emission canister is clogged.

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

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-712

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.13A-34

. 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