Mitsubishi Galant (2004+). Manual - part 1272

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-781

(2) Connect the evaporative emission system pressure pump  

(Miller number 6872A) to the fuel filler hose.

(3) Plug the hose and the nipple shown in the illustration.

NOTE: If these items are not securely plugged now, the fuel 
could leak in the next step.

(4) Pressurize the fuel tank with the evaporative emission 

system pressure pump.

(5) In the pressurized state, check for leaks by applying a 

soapy water solution to each section and look for bubbles.

Q: Are any leaks found?

YES <When there is a leak from the attachment points of 
the fuel pump module, fuel tank differential pressure 
sensor, fuel level sensor (sub) or leveling valve.> : 

Reassemble the leaked parts and check again that 
there are no leaks. Then reinstall the fuel tank (Refer 
to GROUP 13C, Fuel Tank 

P.13C-10

). Then go to 

Step 15   .

YES <When there is a leak from the fuel tank.> : Replace 

the fuel tank (Refer to GROUP 13C, Fuel Tank 

P.13C-10

). Go to Step 15.

NO :  When there is no leak, reinstall the fuel tank (Refer to 

GROUP 13C, Fuel Tank 

P.13C-10

). Then go to Step 

14.

STEP 13. Check the evaporative emission canister for 
vacuum leaks.
(1) Remove the evaporative emission canister (Refer to 

GROUP 17, Evaporative Emission Canister and Fuel Tank 

Pressure Relief Valve 

P.17-97

).

(2) Connect a hand vacuum pump to the evaporative emission 

canister and plug the other nipples.

(3) Apply a pressure on the hand vacuum pump, and confirm 

that air is maintained.

(4) Disconnect the hand vacuum pump and remove the plugs, 

and then install the evaporative emission canister (Refer to 
GROUP 17, Evaporative Emission Canister and Fuel Tank 
Pressure Relief Valve 

P.17-97

).

Q: Is the evaporative emission canister in good condition?

YES : Go to Step 14.
NO :  Replace the evaporative emission canister (Refer to 

GROUP 17, Evaporative Emission Canister and Fuel 
Tank Pressure Relief Valve 

P.17-97

). Then go to Step 

15   .

AC305684

FUEL FILLER HOSE

AB

AC305684AC

AC305682

AB

PLUGS

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-782

STEP 14. 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 automatically increases 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 the 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. 

Disconnect scan tool MB991958.

Q: Is "Evap Leak Mon. Completed. Test Failed and DTCs 

Set" displayed on scan tool MB991958?
YES : Replace the PCM (Refer to 

P.13B-1146

). Then go to 

Step 15  .

NO <"Evap Leak Mon. Completed. Test Passed" is 
displayed on scan tool MB991958.> : The evaporative 

emission system is working properly at this time. Go 
to Step 15                .

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 14.

STEP 15. Perform the OBD-II drive cycle.
(1) Confirm the repair by performing the appropriate drive cycle  

(Refer to Diagnostic Function 

− OBD-ll Drive Cycle − 

Procedure 1 

− Evaporative Emission System Leak Monitor 

P.13B-5

). 

(2) Read the DTC.
Q: Is DTC P0456 set?

YES : Repeat the troubleshooting from Step 1.
NO :  The procedure is complete.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-783

DTC P0461: Fuel Level Sensor (main) Circuit Range/Performance 

Fuel Level Sensor Circuit

AK302865

FUEL LEVEL
SENSOR (SUB)

FUEL LEVEL SENSOR (MAIN)
(INTEGRATED IN FUEL PUMP MODULE)

13

2

1

2

1

11

PINK-

BLA

CK

BLA

CK

PINK-
BLACK

PINK-

BLA

CK

PINK-

BLA

CK

24

GRA

Y

GRA

Y

POWERTRAIN 
CONTROL
MODULE (PCM) 

C-28

      D-18
(MU802058)

      D-17
(MU802004)

CONBINATION METER

1

2 3

4

5

     B-20

22

21

23 24 25

26 27 28 29

30 31 32 33 34

35 36 37 38

39 40 41 42 43

C-25

1

2

AK303156

CONNECTOR: D-17

AB

SERVICE
HOLE

FUEL LEVEL
SENSOR (SUB)

D-17

AK303157

SERVICE
HOLE

AB

FUEL PUMP MODULE
(INCORPORATING FUEL
LEVEL SENSOR (MAIN)
AND FUEL TANK
TEMPERATURE SENSOR)

CONNECTOR: D-18

D-18 (GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-784

.

CIRCUIT OPERATION

• The fuel level sensor (main) drive signal is input 

in PCM (terminal No. 24).

.

TECHNICAL DESCRIPTION

• Branch the drive signal from the fuel level sensor 

circuit, and input it into PCM.

• The PCM detects the amount of fuel left in the 

fuel tank with this signal, and also controls the 
fuel level warning light.

.

DESCRIPTIONS OF MONITOR METHODS
Detect malfunction if change of fuel level sensor out-

put voltage is small when sum of fuel injection is 
large.

.

MONITOR EXECUTION
Continuous

.

MONITOR EXECUTION CONDITIONS (Other 
monitor and Sensor)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• Not applicable

Sensor (The sensor below is determined to be 

normal)

• Not applicable

.

AK303085

CONNECTOR: B-20

PCM

AB

AIR CLEANER

B-20

AK303188

CONNECTOR: C-28

C-28

AB

AK303086

CONNECTOR: C-25

C-25

AB