Mitsubishi Montero (2004+). Manual - part 260

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-527

LOGIC FLOW CHARTS (Monitor Sequence)

.

DTC SET CONDITIONS
Remaining fuel amount is 15 

− 40 percent of capacity 

(fuel level sensor output signal voltage is 1.4 

− 2.4 

volts).

Check Conditions A: At Start up

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

when the engine is started.

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

or less when the engine is started.

Check Conditions B: For Test to Run

• Fuel temperature is less than 36 °C (97 °F), and 

less than 13 minutes have elapsed since the 
engine was started.

• Engine coolant temperature is greater than 57°C 

(135

°F).

• Power steering pressure switch: "OFF"

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-528

• Barometric pressure is greater than 76 kPa (11 

psi).

• Fuel tank differential pressure sensor output volt-

age is 1 to 4 volts.

• Vehicle speed is greater than or equal to 20 km/h 

(12.4 mph).

Check Conditions C: For Test to Stop

• Intake air temperature is greater than −10°C 

(14

°F).

• When the evaporative emission purge solenoid 

and evaporative emission ventilation solenoid are 
closed, the pressure in the fuel tank is less than 
451 Pa (0.065 psi).

• The pressure fluctuation is less than 647 Pa 

(0.094 psi).

• 10 seconds have elapsed since the start of the 

previous monitoring.

• Monitoring time: 75 − 125 seconds.

Judgment Criteria

• Internal pressure of the fuel tank has changed 

more than 785 Pa (0.114 psi) in 20 seconds after 
the tank and vapor line were closed.
NOTE: The monitoring time (75 

−

 125 seconds) 

depends on the fuel level and the temperature in 
the fuel tank.
The next monitoring occurs at least 10 seconds 
later.

.

DTC SET CONDITIONS
Remaining fuel amount is 40 

− 85 percent of capacity 

(fuel level sensor output voltage is 2.4 

− 3.7 volts).

Check Conditions A: At Start up

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

when the engine is started.

• The engine coolant temperature is less than 36 

°C (97 °F) when the engine is started.

Check Conditions B: For Test to Run

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

• Barometric pressure is greater than 76 kPa (11 

psi).

• Fuel tank differential pressure sensor output volt-

age is 1 to 4 volts.

Check Conditions C: For Test to Stop

• Intake air temperature is greater than −10 °C 

(14

°F).

• Engine coolant temperature is greater than 20 °C 

(68 

°F).

• When the evaporative emission purge solenoid 

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

• 10 seconds have elapsed since the start of the 

previous monitoring.

• Monitoring time: 10 − 14 minutes.

Judgment Criteria

• Internal pressure of the fuel tank has changed 

more than 2 kPa (0.29 psi) in 128 seconds after 
the tank and vapor line were closed.
NOTE: The monitoring time (10 

−

 14 minutes) 

depends on the fuel level and the temperature in 
the fuel tank.
The next monitoring occurs at least 10 seconds 
later.

.

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 does 

not seal.

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

• MB991658: Test Harness Set

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-529

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, then 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-530

STEP 2. Check for leaks in the evaporative emission purge 
solenoid.
(1) Disconnect hose B from the evaporative emission purge 

solenoid and connect a hand vacuum pump to the nipple of 
the evaporative emission purge solenoid.

(2) Use the hand vacuum pump to confirm that the evaporative 

emission purge solenoid holds vacuum.

(3) Disconnect the hand vacuum pump and connect hose B to 

the evaporative emission purge solenoid.

Q: Does the evaporative emission purge solenoid hold 

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

to Step 18.

STEP 3. Check for leaks in the evaporative emission 
system hose A and hose B.

Perform a leakage test with a hand vacuum pump on each 
hose A and B.

Q: Does the hoses hold vacuum?

YES : Go to Step 4.
NO :  Replace any damaged hose. Go to Step 18.

AC203994 AB

HOSE A

HOSE B

EVAPORATIVE EMISSION

PURGE SOLENOID

AC203996

AB

EVAPORATIVE EMISSION

PURGE SOLENOID

AC203994 AB

HOSE A

HOSE B

EVAPORATIVE EMISSION

PURGE SOLENOID