Mitsubishi Montero (2004+). Manual - part 280

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-607

STEP 13. Check the harness wires between PCM 
connector D-134 terminal 82 and fuel tank differential 
pressure sensor connector G-05 terminal 1 for damage. 
Q: Are the harness wires in good condition?

YES : It can be assumed that this malfunction is intermittent. 

(Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

− How to 

Cope with Intermittent Malfunction 

P.00-6

). Go to 

Step 15.

NO :  Repair the damaged harness wires. Go to Step 15.

AC203997

CONNECTOR: D-134

AC

D-134 (GR)

PCM

D-134 HARNESS CONNECTOR:
HARNESS SIDE

64

63

65 66 67 68

62

61

69 70 71 72 73

74 75 76 77 78 79 80 81 82
83 84

85 86 87

88 89

ACX00218

CONNECTOR : G-05

AR

G-05 (B)

SECOND SEAT UNDER
SERVICE HOLE

G-05 HARNESS
CONNECTOR:
COMPONENT SIDE

1

2

3

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-608

STEP 14. Using scan tool MB991958, check data list item 
73: Fuel Tank Differential Pressure Sensor.

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) Disconnect hose F from the evaporative emission canister 

side, and plug the hose.

(3) Turn the ignition switch to the "ON" position.
(4) Remove the fuel cap.
(5) Set scan tool MB991958 to the data reading mode.

Item 73, Fuel Tank Differential Pressure Sensor.

• The fuel tank pressures reading on the scan tool 

should be 

−1.5 to 1.5 kPa (−0.443 to 0.443 inHg).

(6) Connect an evaporative emission system pressure pump to 

the fuel tank filler tube and pressurize the fuel tank.

• The fuel tank pressure reading should increase.

(7) Disconnect an evaporative emission system pressure pump 

and connect hose F.

(8) Turn the ignition switch to the "LOCK" (OFF) position and 

disconnect scan tool MB991958.

Q: Is the fuel tank pressure between 

−1.5 and 1.5 kPa 

(

−0.443 and 0.443 inHg)?

YES : It can be assumed that this malfunction is intermittent. 

(Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

− How to 

Cope with Intermittent Malfunction 

P.00-6

). Go to 

Step 15.

NO :  Replace the PCM (Refer to 

P.13A-1014

). Go to Step 

15      .

AC306409AF

MB991911

MB991824

MB991827

AC102602 AC

HOSE F

ACX01358

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-609

STEP 15. Perform the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern (Refer to 

Diagnostic Function 

− OBD-ll Drive Cycle − Procedure 1 − 

Evaporative Emission System Leak Monitor 

P.13A-4

).

(2) Read the diagnostic trouble code (DTC).
Q: Is DTC P0453 set?

YES : Repeat the troubleshooting from Step 2.
NO :  The procedure is complete.

DTC P0455: Evaporative Emission System Leak Detected (Gross Leak)

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

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-610

.

TECHNICAL DESCRIPTION

• The fuel tank may be under a slight positive and 

negative pressure depending on the state of the 
evaporative emission system. The PCM monitors 
and responds to these pressure changes. If the 
pressure varies from the specified range, the 
PCM will set DTC P0455.

• The PCM energizes the evaporative emission 

ventilation solenoid to shut off the evaporative 
emission canister outlet port.

• The evaporative emission purge solenoid is to 

apply engine manifold vacuum to the evaporative 
emission system.

• When the fuel system develops a vacuum of 2 

kPa (0.29 psi), the evaporative emission purge 
solenoid is turned "OFF" and the fuel system vac-
uum is maintained at 2 kPa (0.29 psi).

• The PCM determines if there is a leak or clog in 

the fuel system by measuring the change of vac-
uum inside the fuel tank.

• The test is stopped when fuel vapor pressure is 

determined to be too high.

.

DESCRIPTIONS OF MONITOR METHODS

• Depressurizing EVAP system by intake manifold 

negative pressure is impossible within specified 
period.

.

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

.

AC101763 AB

REAR COIL SPRING (RH)

EVAPORATIVE EMISSION VENTILATION 
SOLENOID