Mitsubishi Lancer Evolution X. Manual - part 347

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-453

(6) Connect the evaporative emission system pressure pump 

(Miller number 6872A) to the fuel tank filler tube by using 
fuel tank adapter (MLR-8382) and pressurize the fuel tank.

• The fuel tank pressure reading should increase.

(7) Turn the ignition switch to the "LOCK" (OFF) position. Then 

disconnect scan tool MB991958.

(8) Remove the evaporative emission system pressure pump 

(Miller number 6872A) and the fuel tank adapter 
(MLR-8382), and reinstall the fuel cap.

(9) Connect hose E to the evaporative emission canister.
Q: Is the sensor operating properly?

YES : It can be assumed that this malfunction is intermittent. 

Refer to GROUP 00, How to Use Troubleshooting / 
Inspection Service Points − How to Cope with 

Intermittent Malfunctions 

P.00-15

.

NO :  Go to Step 2 .

STEP 2. Check harness connector D-21 at fuel tank 
differential pressure sensor for damage.
Q: Is the harness connector in good condition?

YES : Go to Step 3 .
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 12 .

STEP 3. Measure the sensor supply voltage at fuel tank 
differential pressure sensor connector D-21 by 
backprobing.
(1) Do not disconnect the connector D-21.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal No. 3 and ground by 

backprobing.

• Voltage should be between 4.9 and 5.1 volts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.9 and 5.1 volts?

YES : Go to Step 6 .
NO :  Go to Step 4 .

STEP 4. Check harness connector B-10 at ECM for 
damage.
Q: Is the harness connector in good condition?

YES : Go to step 5 .
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 12 .

AK704700

3

2

1

AK704395

D-21 harness 
connector: 
harness side

AC

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-454

STEP 5. Check for harness damage between fuel tank 
differential pressure sensor connector D-21 (terminal No. 
3) and ECM connector B-10 (terminal No. 114).
NOTE: Check harness after checking intermediate connector 
C-47. If intermediate connector is damaged, repair or replace it. 
Refer to GROUP 00E, Harness Connector Inspection 

P.00E-2

. 

Then go to Step 12 .
Q: Is the harness wire in good condition?

YES : Go to Step 11 .
NO :  Repair it. Then go to Step 12 .

STEP 6. Measure the ground voltage at fuel tank 
differential pressure sensor connector D-21 by 
backprobing.
(1) Do not disconnect the connector D-21.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal No. 2 and ground by 

backprobing.

• Voltage should be 0.5 volt or less.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage 0.5 volt or less?

YES : Go to Step 9 .
NO :  Go to Step 7 .

STEP 7. Check harness connector B-10 at ECM for 
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 8 .
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 12 .

STEP 8. Check for harness damage between fuel tank 
differential pressure sensor connector D-21 (terminal No. 
2) and ECM connector B-10 (terminal No. 113).
NOTE: Check harness after checking intermediate connector 
C-47. If intermediate connector is damaged, repair or replace it. 
Refer to GROUP 00E, Harness Connector Inspection 

P.00E-2

. 

Then go to Step 12 .
Q: Is the harness wire in good condition?

YES : Go to Step 11 .
NO :  Repair it. Then go to Step 12 .

3

2

1

AK704396

D-21 harness 
connector: 
harness side

AC

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-455

STEP 9. Check harness connector B-10 at ECM for 
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 10 .
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 12 .

STEP 10. Check for harness damage between fuel tank 
differential pressure sensor connector D-21 (terminal No. 
1) and ECM connector B-10 (terminal No. 112).
NOTE: Check harness after checking intermediate connector 
C-47. If intermediate connector is damaged, repair or replace it. 
Refer to GROUP 00E, Harness Connector Inspection 

P.00E-2

. 

Then go to Step 12 .
Q: Is the harness wire in good condition?

YES : Go to Step 11 .
NO :  Repair it. Then go to Step 12 .

STEP 11. Replace the fuel tank differential pressure 
sensor.
(1) Replace the fuel tank differential pressure sensor.
(2) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function − OBD-II Drive Cycle −  Pattern 4 

P.13A-9

.

(3) Check the diagnostic trouble code (DTC).
Q: Is DTC P0450 set?

YES : Replace the ECM. When the ECM is replaced, 

register the ID code. Refer to GROUP 42B, Diagnosis 
− ID Code Registration Judgment Table <Vehicles with 

KOS> 

P.42B-11

 or GROUP 42C, Diagnosis − ID Code 

Registration Judgment Table <Vehicles with WCM> 

P.42C-9

. Then go to Step 12 .

NO :  The inspection is complete.

STEP 12. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function − OBD-II Drive Cycle − Pattern 4 

P.13A-9

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0450 set?

YES : Repeat the troubleshooting.
NO :  The inspection is complete.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-456

DTC P0451: Evaporative Emission Control System Pressure Sensor Range/Performance

AK704684

L

A

B

C

D

E

F

H

G

I

J

K

AB

Intake manifold

Fuel tank

Check valve

Evaporative emission
purge solenoid

Evaporative emission
ventilation solenoid

Evaporative emission
canister

Fuel tank differential 
pressure sensor

System diagram

Air filter

Vent pipe