Mitsubishi Galant (2004+). Manual — part 1269

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-769

STEP 18. 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 automatically increases 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 the 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.

Disconnect scan tool MB991958.

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

Set" displayed on scan tool MB991958?
YES : Replace the PCM (Refer to

P.13B-1146

). Then go to

Step 19 .

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

emission system is working properly at this time. Go
to Step 19 .

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 18.

STEP 19. Perform the OBD-II drive cycle.
(1) Confirm the repair by performing the appropriate drive cycle

(Refer to Diagnostic Function

− OBD-ll Drive Cycle −

Procedure 1

− Evaporative Emission System Leak Monitor

P.13B-5

).

(2) Read the DTC.
Q: Is DTC P0455 set?

YES : Repeat the troubleshooting from Step 1.
NO : The procedure is complete.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-770

DTC P0456: Evaporative Emission System Leak Detected (Very Small Leak)

.

AC306278

A

B

C

D

E

F

G

O

P

Q

N

M

L

H

I

J

K

AB

INTAKE MANIFOLD PLENUM

FUEL TANK

EVAPORATIVE EMISSION
VENTILATION SOLENOID

CHECK VALVE

EVAPORATIVE EMISSION
PURGE SOLENOID

EVAPORATIVE
EMISSION CANISTER

ONBOARD REFUELING
VAPOR RECOVERY(ORVR)
VENT VALVE MODULE

SYSTEM DIAGRAM

CHAMBER

AC306400

AB

EVAPORATIVE EMISSION CANISTER

AC306388AB

EVAPORATIVE EMISSION
PURGE SOLENOID

AC305053AC

EVAPORATIVE EMISSION
VENTILATION SOLENOID

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-771

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-772

LOGIC FLOW CHARTS (Monitor Sequence)

.

DTC SET CONDITIONS

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.

• The fuel level sensor output voltage is 2.4 − 3.7

volts when the engine starts and the amount of
remaining fuel is 40

− 85 percent of capacity.

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