Mitsubishi Eclipse. Manual - part 270

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-573

LOGIC FLOW CHARTS (Monitor Sequence)

.

DTC SET CONDITIONS

Test Conditions A: At Start up

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

when the engine is started.

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

less when the engine is started.

Test Conditions B: For Test to Run

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

more <i.e. the amount of remaining fuel is 15 

− 40 

percent>.

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

more <i.e. the amount of remaining fuel is 40 

− 85 

percent>.

• Engine speed is 1,600 r/min or more.

• Barometric pressure is above 76 kPa (11 psi).

START

END

MONITORING 
CONDITIONS?

GROSS LEAK

MONITORING CONDITIONS

SPECIFIED TIMES 

MONITORED

SPECIFIED TIMES 

HAVE PASSED

YES

NO

DEPRESSURIZE FUEL TANK PRESSURE

NO

YES

YES

YES

SHUT PURGE LINE

MALFUNCTION

MALFUNCTION

(GROSS LEAK)

GOOD

YES

NO

NO

NO

AC210304

0.04in, 0.02in GROSS LEAK MONITOR

MEASURE REVERTING
PRESSURE :    

PFT

PFT > PT

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-574

• Volumetric efficiency is between 20 and 80 per-

cent.

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

• Fuel tank differential pressure sensor output volt-

age 1 

− 4 volts.

Test Conditions C: For Test to Stop

• Intake air temperature is less than 5°C (41°F).

• When the evaporative emission purge solenoid 

and evaporative emission ventilation solenoid are 
closed, the pressure rises higher 451 Pa (0.065 
psi) <i.e. the amount of remaining fuel is 15 

− 40 

percent>.

• When the evaporative emission purge solenoid 

and evaporative emission ventilation solenoid are 
closed, the pressure rises higher 324 Pa (0.047 
psi) <i.e. the amount of remaining fuel is 40 

− 85 

percent>.

• 10 seconds have elapsed from the start of the 

previous monitoring.

Judgment Criteria

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

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

NOTE: The monitoring time (150 seconds) depends 
on the fuel level and the temperature in the fuel tank.

.

OBD-ll DRIVE CYCLE PATTERN
Refer to Diagnostic Function 

− OBD-ll Drive Cycle − 

Procedure 1 

− Evaporative Emission System 

Leak Monitor 

P.13A-5

.

.

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 failed.

• Evaporative emission ventilation solenoid failed.

• Fuel tank differential pressure sensor failed.

• Evaporative emission canister seal is faulty.

• Evaporative emission canister is clogged.

.

OVERVIEW OF TROUBLESHOOTING

• To determine the cause of DTC P0455, a perfor-

mance test is needed. The performance test uses 
a mechanical vacuum gauge and scan tool 
MB991958 or MB991958 set on the fuel tank dif-
ferential pressure sensor (TANK PRES SNER 
73.) The mechanical gauge reading is used to 
verify scan tool MB991958 or MB991958 reading. 
A comparison of the mechanical gauge reading 
to scan tool MB991958 or MB991958 reading 
determines the reading problem in the system.

• Prior to doing the performance test, several sim-

ple inspections are needed to exclude some pos-
sibilities of the symptom.

DIAGNOSIS

Required Special Tool:

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

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-575

STEP 1. Using scan tool MB991958, check 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.

• With this monitor, the ECM <M/T> or PCM <A/T> auto-

matically increases the engine speed to 1,600 r/min or 
more. Check that the transaxle is set to "neutral" <M/T> 
or "P" <A/T> 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 the 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," and press the "YES" key.
(7) Select "Evap Leak Mon," and press the "YES" key.
(8) During the monitor, keep the accelerator pedal at the idling 

position.
NOTE: If the engine speed does not reach 2,000 r/min dur-
ing the monitor test, adjustment of the Speed Adjusting 
Screw may be needed. Refer to 

P.13A-928

. And adjust to 

the standard value.

(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."

Q: What is displayed on scan tool MB991958?

"Evap Leak Mon. Completed. Test Passed" : The 

evaporative emission system is working properly at 
this time. Explain to customer that improperly 
tightened fuel cap can cause MIL to turn on, and 
return the vehicle.

"Evap Leak Mon. Completed. Test Failed and DTCs Set" 
: 

A malfunction has been detected during the monitor 
test. Go to Step 2.

"Evap Lead Mon. discontinued. Retest again from the 
first" : The monitor was discontinued for a certain reason 

(vehicle speed input from computer, engine speed 
and engine load deviating from specified range). Turn 
the ignition switch to the "LOCK" (OFF) position once, 
and repeat the monitoring from the Step 1.

AC303127

AB

MB991911

16-PIN

MB991827

MB991824 

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-576

STEP 2. Using scan tool MB991958, check solenoid for 
clogging of the purge control.
(1) Disconnect hoses A and B from the evaporative emission 

purge solenoid side, and connect the hand vacuum pump to 
the evaporative emission purge solenoid instead of hose B.

(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991958 to actuator test mode for item 08: 

Evaporative Emission Purge Solenoid. When the 
evaporative emission purge solenoid is operated, apply a 
pressure on the hand vacuum pump and confirm that air is 
blown from the other side nipple.

(4) Turn the ignition switch to the "LOCK" (OFF) position. Then 

disconnect scan tool MB991958.

(5) Disconnect the hand vacuum pump, and connect hoses A 

and B to the evaporative emission purge solenoid.

Q: Is the solenoid in good condition?

YES : Go to Step 3.
NO :  Replace the evaporative emission purge solenoid. 

Then go to Step 27.

STEP 3. Check for leaks and clogging in the evaporator 
line hose A to hose C.
Q: Are the hoses in good condition?

YES : Go to Step 4.
NO :  Replace the inferior hose. Then go to Step 27.

STEP 4. Check for leaks and clogging in the chamber.
(1) When you blow the chamber, it should pass less air.
(2) When you blow the chamber, on air should leak from the 

chamber body.

Q: Is the chamber in good condition?

YES : Go to Step 5.
NO :  Replace the chamber. Then go to Step 27.

AC000223

THROTTLE 
BODY

HOSE B

HOSE A

AG

AC000182

EVAPORATIVE EMISSION
PURGE SOLENOID

AB

AC000223

THROTTLE 
BODY

HOSE B

HOSE A

HOSE C

AE

AC000223

THROTTLE 
BODY

CHAMBER

AF