Mitsubishi Montero Sport (2004+). Manual - part 302

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-621

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)

• Volume airflow sensor

• Barometric pressure sensor

• Intake air temperature sensor

• Engine coolant temperature sensor

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-622

LOGIC FLOW CHARTS (Monitor Sequence)

.

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-623

DTC SET CONDITIONS

Test Conditions:

• Fuel level sensor output voltage is 2.4 − 3.7 volts 

when the engine is started, and the amount of 
remaining fuel is 40 

− 85 percent of capacity.

• 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 greater than 20 °C 

(68 

°F).

• Intake air temperature is greater than −10 °C (14 

°F).

• Fuel temperature is less than 33 °C (91 °F).

• Barometric pressure is greater than 76 kPa (11 

psi).

• Fuel tank differential pressure sensor output volt-

age is 1 

− 4 volts.

• When the evaporative emission purge solenoid 

and evaporative emission ventilation solenoid are 
closed, the pressure rises in the fuel tank is less 
than 324 Pa (0.047 psi).

• 10 seconds have elapsed from the start of the 

previous monitoring.

• Monitoring time: 10 − 14 minutes.

Judgment Criteria:

• Internal pressure of the fuel tank has changed 

greater than 1,177 

− 1,373 Pa (0.177 − 0.199 psi) 

in 128 seconds after the 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.

• Evaporative emission canister seal is leaking.

• Fuel tank, purge line or vapor line seal is leaking.

• Evaporative emission ventilation solenoid dose 

not seal.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-624

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

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" and press the "YES" key.
(7) Select "Evap Leak Mon." and press the "YES" key.
(8) During this test, 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, adjust the Speed Adjusting Screw 
(Refer to 

P.13A-883

), 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".

(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 

P.13A-26

, and diagnose any other DTCs that are set. 

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 monitor test.

AK303629AB

MB991911

MB991827

MB991824 

16-PIN