Mitsubishi Galant (2004+). Manual - part 1270

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-773

Check Conditions B: For Test to Run

• Barometric pressure is greater than 76 kPa (11 

psi).

• The fuel tank temperature is 33°C (91°F) or less.

• Fuel tank differential pressure sensor output volt-

age is 1 to 4 volts.

Check Conditions C: For Test to Stop

• Engine coolant temperature is greater than 20 °C 

(68 

°F).

• 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 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 

more 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.13B-5

.

.

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.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-774

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A

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 PCM will automatically increase 

the engine speed to 1,600 r/min or greater. Check that 
the transaxle is set to the "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 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.13B-33

. 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 from Step 1.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-775

STEP 2. Check the evaporative emission purge solenoid 
for leaks.

(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 reconnect 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. 

Then go to Step 15.

STEP 3. Check for leaks in evaporative emission hoses A 
through D.

Use a hand vacuum pump to test each hose from hose A to 
hose D.

Q: Do the hoses hold vacuum?

YES : Go to Step 4.
NO :  Replace any damaged hose. Then go to Step 15.

STEP 4. Check for leaks in the chamber.

(1) Connect a hand vacuum pump to the nipple.
(2) Plug the other nipple.

(3) Apply vacuum with the hand vacuum pump, and confirm 

that the applied vacuum does not fluctuate.

Q: Is the chamber in good condition?

YES : Go to Step 5.
NO :  Replace the chamber. Then go to Step 15.

AC306390AB

HOSE B

AC306388

AC306389AB

HOSE C

HOSE B

HOSE A

AC306799

AB

HOSE D

THROTTLE BODY

AC306388

AC306389AC

CHAMBER

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-776

STEP 5. Check for leaks in evaporative emission hoses E 
through G.

Use a hand vacuum pump to test each hose from hose E to 
hose G.

Q: Do the hoses hold vacuum?

YES :  Go to Step 6.
NO :  Replace any damaged hose. Then go to Step 15.

AC306710

HOSE E

AC

AC306401

HOSE G

HOSE F

AD