Mitsubishi Montero (2004+). Manual - part 281

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-611

LOGIC FLOW CHARTS (Monitor Sequence)

.

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 57°C (135°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

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-612

• Volumetric efficiency is between 20 and 70 per-

cent.

• The fuel 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.

.

OBD-ll DRIVE CYCLE PATTERN
Refer to Diagnostic Function 

− OBD-ll Drive Cycle − 

Procedure 1 

− Evaporative Emission System Leak 

Monitor 

P.13A-4

.

.

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

• MB991911: MUT-III main harness B

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-613

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.

• During this test, the PCM automatically increases the 

engine speed to 1,600 r/min or greater. Check that the 
transmission is set to "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 idling 

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-26

. 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.

AC306409AF

MB991911

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-614

STEP 2. Check for leaks in the evaporative emission purge 
solenoid.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link 

connectMB991958or.

(2) Disconnect hoses A and B from the evaporative emission 

purge solenoid.

(3) Connect the hand vacuum pump to the evaporative 

emission purge solenoid instead of hose A.

(4) Turn the ignition switch to the "ON" position.
(5) Set scan tool MB991958 to actuator test mode.

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.

(6) Turn the ignition switch to the "LOCK" (OFF) position.
(7) Disconnect the hand vacuum pump and connect hoses A 

and B to the evaporative emission purge solenoid.

Q: Does the evaporative emission purge solenoid nipple 

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

to Step 26.

AC306409AF

MB991911

MB991824

MB991827

AC203994 AB

HOSE A

HOSE B

EVAPORATIVE EMISSION

PURGE SOLENOID

AC203995 AB

EVAPORATIVE EMISSION

PURGE SOLENOID