Mitsubishi Lancer Evolution X. Manual - part 357

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-493

STEP 12. Check the evaporative emission canister for 
vacuum leaks.
(1) Connect a hand vacuum pump to the evaporative emission 

canister and plug the other nipples.

(2) Apply a pressure on the hand vacuum pump, and confirm 

that air is maintained.

(3) Disconnect the hand vacuum pump and remove the plugs.
Q: Is the evaporative emission canister in good condition?

YES : Go to Step 13 .
NO :  Replace the evaporative emission canister. Then go 

to Step 14 .

STEP 13. Using scan tool MB991958, check the 
evaporative emission system monitor test.

CAUTION

• During this test, the ECM automatically increases the 

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

(1) Turn the ignition switch to the "ON" position.
(2) Erase the DTCs using scan tool MB991958.
(3) Check that the fuel cap is securely closed (Tighten until 

three clicks are heard).

(4) Start the engine.
(5) Select "Special Function"
(6) Select "Evap Leak Monitor"
(7) During the test, keep the accelerator pedal at the idle 

position.

(8) 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".

(9) Turn the ignition switch to the "LOCK" (OFF) position. 
Q: Is "Evap Leak Mon. Completed. Test Failed and DTCs 

Set" displayed on scan tool MB991958?
YES : Replace the ECM. When the ECM is replaced, 

register the ID code. Refer to GROUP 42B, ID Code 
Registration Judgment Table <Vehicles with KOS> 

P.42B-11

 or GROUP 42C, ID Code Registration 

Judgment Table <Vehicles with WCM> 

P.42C-9

. Then 

go to Step 14 .

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 14        .

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.

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Plugs

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MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-494

STEP 14. 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 − Pattern 4 

P.13A-9

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0455 set?

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

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

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A

B

C

D

E

F

H

G

I

J

K

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Intake manifold

Fuel tank

Check valve

Evaporative emission
purge solenoid

Evaporative emission
ventilation solenoid

Evaporative emission
canister

Fuel tank differential 
pressure sensor

System diagram

Air filter

Vent pipe

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Evaporative emission canister

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Evaporative emission purge solenoid

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-495

.

TECHNICAL DESCRIPTION

• The ECM monitors the Evaporative Emission 

(EVAP) System pressure.

• The ECM 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 ECM 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 mal-
function 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 tank 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

.

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Evaporative emission
ventilation solenoid

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MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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DTC SET CONDITIONS

Logic Flow Chart (Monitor Sequence)

.

Check Conditions

• Engine coolant temperature is less than 36° C 

(97° F) when the engine is started.

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

when the engine is started.

• Engine coolant temperature is more than 20° C 

(68° F).

• When the evaporative emission purge solenoid 

and evaporative emission ventilation solenoid are 
closed, the change of the pressure in the fuel 
tank is less than 324 Pa (0.09 in.Hg).

• Amount of remaining fuel is 40 − 85 percent of 

capacity when the engine is started.

• Barometric pressure is more than 76 kPa (22.4 

in.Hg).

• Intake air temperature is more than −10° C (14° F).
• Fuel temperature is less than 33° C (91° F).

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Start

Yes

No

Monitoring 
conditions?

Depressurize fuel tank pressure

Yes

Yes

No

No

Gross leak 

monitoring conditions

Shut purge line

Specified times

have passed

Malfunction

(Gross leak)

Measure reverting
pressure:     PFT  

Yes

Yes

No

No

PFT > PT

Specified times

monitored

Malfunction

End

Good