Mitsubishi Galant 9G. Manual — part 1129

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-816

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-34

. 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-817

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.

AC306390AB

HOSE B

AC306388

AC306389AB

HOSE C

HOSE B

HOSE A

AC306799

AB

HOSE D

THROTTLE BODY

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-818

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.

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.

AC306388

AC306389AC

CHAMBER

AC306710

HOSE E

AC

AC306401

HOSE G

HOSE F

AD

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-819

STEP 6. Using scan tool MB991958, check data list item 29:
Evaporative emission ventilation solenoid.

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) Remove the fuel tank filler tube protector (Refer to GROUP

13C, Fuel Tank

P.13C-10

).

(3) Disconnect the hose G and evaporative emission canister

connection, and connect the hand vacuum pump to the
hose G.

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

• Item 29: 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, and

disconnect scan tool MB991958.

(7) Disconnect the hand vacuum pump, and connect hose G to

the evaporative emission canister.

(8) Reinstall the fuel tank filler tube protector (Refer to GROUP

13C, Fuel Tank

P.13C-10

).

Q: Did the evaporative emission ventilation solenoid hold

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

(Refer to GROUP 17, Evaporative emission canister
and fuel tank pressure relief valve removal and
installation

P.17-95

). Then go to Step 15.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC306777

AC

HOSE G