Mitsubishi Montero (2004+). Manual - part 259

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-523

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991911: Main Harness B

STEP 1. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).

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 connector.
(2) Turn the ignition switch to the "ON" position.
(3) Read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC P0451 set?

YES : Refer to DTC P0451 - Evaporative Emission Control 

System Pressure Sensor Range/Performance 

P.13A-558

.

NO :  Go to Step 2. 

STEP 2. Using scan tool MB991958, check data list item 73: 
Fuel Tank Differential Pressure Sensor.
(1) Turn the ignition switch to the "ON" position.
(2) Remove the fuel cap.
(3) Set scan tool MB991958 to the data reading mode for item 

73, Fuel Tank Differential Pressure Sensor.

• The fuel tank differential pressures should be −3.3 to 3.3 

kPa (

−0.97 to 0.97 in.Hg).

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the fuel tank pressure 

−3.3 to 3.3 kPa (−0.97 to 0.97 

inHg)?
YES : Go to Step 3.
NO :  Refer to DTC P0451 - Evaporative Emission Control 

System Pressure Sensor Range/Performance 

P.13A-558

.

AK302970

AB

MB991911

MB991824

MB991827

AK302970

AB

MB991911

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-524

STEP 3. Using scan tool MB991958, check actuator test 
item 08: Evaporative Emission Purge Solenoid.
(1) Turn the ignition switch to the "ON" position.
(2) Set scan tool MB991958 to the actuator test mode for item 

08, Evaporative emission purge solenoid.

• An operation sound should be heard and vibration 

should be felt when the evaporative emission purge 
solenoid is operated.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the solenoid operating properly?

YES : Go to Step 4.
NO :  Replace the evaporative emission purge solenoid. 

Then go to Step 5.

STEP 4. Using scan tool MB991958, check actuator test 
item 29: Evaporative Emission Ventilation Solenoid.
(1) Turn the ignition switch to the "ON" position.
(2) Set scan tool MB991958 to the actuator test mode for item 

29, Evaporative emission ventilation solenoid.

• An operation sound should be heard and vibration 

should be felt when the evaporative emission ventilation 
solenoid is operated.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the solenoid operating properly?

YES : Repair or replace the vent hose and air filter. Then go 

to Step 5.

NO :  Replace the evaporative emission ventilation 

solenoid. Then go to Step 5.

STEP 5 Perform the OBD-II drive cycle. 
(1) Carry out a test drive with the drive cycle pattern. (Refer to 

Diagnostic Function 

− OBD-II Drive Cycle − Procedure 1 − 

Evaporative Emission System Leak Monitor 

P.13A-4

.)

(2) Check the diagnostic trouble code.
Q: Is DTC P0441 set?

YES : Go to Step 1.
NO :  The procedure is complete.

AK302970

AB

MB991911

MB991824

MB991827

AK302970

AB

MB991911

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-525

DTC P0442: Evaporative Emission System Leak Detected (Small Leak)

.

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.

AC203991

SYSTEM DIAGRAM

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

Q

S

R

P

FUEL TANK

CHECK VALVE B

CHECK VALVE A

EVAPORATIVE
EMISSION
PURGE
SOLENOID

EVAPORATIVE EMISSION
VENTILATION SOLENOID

EVAPORATIVE
EMISSION
CANISTER

VENT PIPE
ASSEMBLY

AD

ONBOARD REFUELING
VAPOR RECOVERY(ORVR)
VENT VALVE MODULE

AC101766

EVAPORATIVE EMISSION CANISTER

AB

AC203904

AC

EVAPORATIVE EMISSION
PURGE SOLENOID

INTAKE AIR DUCT

AC101763 AB

REAR COIL SPRING (RH)

EVAPORATIVE EMISSION VENTILATION 
SOLENOID

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-526

• 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

.