Mitsubishi Lancer Evolution X. Manual - part 358

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-497

• Fuel tank differential pressure sensor output volt-

age is between 1.0 and 4.0 volts.

• At least 10 seconds have passed since the last 

monitor was complete.

• Monitoring time: 10 − 14 minutes

Judgement Criterion

• In case the amount of change in the pressure that 

is monitored for a given length of time inside the 
tank is beyond the specified value after sealing 
off the fuel tank and the vapor line.
NOTE: The specified value varies depending on 
the fuel temperature and fuel level.

.

FAIL-SAFE AND BACKUP FUNCTION

• None

.

OBD-ll DRIVE CYCLE PATTERN

Refer to Diagnostic Function − OBD-II Drive Cycle − 

Pattern 5 

P.13A-9

.

.

TROUBLESHOOTING HINTS (THE MOST 
LIKELY CAUSES FOR THIS CODE TO BE 
SET ARE:)

• Loose fuel cap.
• Fuel cap relief pressure is incorrect.
• Malfunction of the evaporative emission canister 

seal.

• Malfunction of the fuel tank, purge line or vapor 

line seal.

• Malfunction of the evaporative emission ventila-

tion solenoid.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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STEP 1. Using scan tool MB991958, check the 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 ECM will automatically increase 

the engine speed to 1,600 r/min or greater. Check that 
the transaxle 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 "Special Function"
(7) Select "Evap Leak Monitor"
(8) During this test, keep the accelerator pedal at the idle 

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-48

. 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.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-499

STEP 2. Test check valve.
(1) Check valve is a one-way check valve.

(2) Check valve should allow air to flow in only one direction.
Q: Does check valve allow air to pass in one direction 

only?
YES : Go to Step 3 .
NO :  Replace check valve. Then go to Step 14 .

STEP 3. Check for leaks in evaporative emission hoses A 
and B.
Use a hand vacuum pump to test each hose A and B.
Q: Do the hoses hold vacuum?

YES : Go to Step 4 .
NO :  Replace any damaged hose. Then go to Step 14 .

STEP 4. Check the evaporative emission purge solenoid 
for leaks.
Refer to GROUP 17, Emission Control − Evaporative Emission 

Control System − Evaporative Emission Purge Solenoid Check 

P.17-76

.

Q: Is the evaporative emission purge solenoid operating 

properly?
YES : Go to Step 5 .
NO :  Replace the evaporative emission purge solenoid. 

Then go to Step 14 .

AK704695

Check valve

AB

AK604287AB

Check valve

AK704688

Hose B

Hose A

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-500

STEP 5. Check for leaks in evaporative emission hoses C 
and D.
Use a hand vacuum pump to test each hose C and D.
Q: Do the hoses hold vacuum?

YES : Go to Step 6 .
NO :  Replace any damaged hose. Then go to Step 14 .

STEP 6. Using scan tool MB991958, check actuator test 
item 15: Evaporative emission ventilation solenoid.
(1) Remove the canister cover.
(2) Remove the evaporative emission ventilation solenoid. Do 

not disconnect the connector.

(3) Connect the hose of the hand vacuum pump to the canister 

side nipple of the evaporative emission ventilation solenoid.

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

• Item 15: Evaporative Emission Ventilation Solenoid.

• While the evaporative emission ventilation solenoid 

is energized, operate the hand vacuum pump and 
confirm that the solenoid holds vacuum.

(6) Turn the ignition switch to the "LOCK" (OFF) position.
(7) Disconnect the hand vacuum pump, and reinstall the 

evaporative emission ventilation solenoid.

(8) Reinstall the canister cover.
Q: Did the evaporative emission ventilation solenoid hold 

vacuum?
YES : Go to Step 7 .
NO :  Replace the evaporative emission ventilation 

solenoid. Then go to Step 14 .

AK704689

Hose C

AB

AK704690 AB

Hose D

AK704699 AB

Evaporative emission
ventilation solenoid

Canister
side nipple

Evaporative emission
ventilation solenoid