Mitsubishi Lancer Evolution X. Manual - part 422

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-753

STEP 6. Using scan tool MB991958, check data list.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following items in the data list. Refer to Data List 

Reference Table 

P.13A-818

.

a. Item 5: Intake Air Temperature Sensor.
b. Item 6: Engine Coolant Temperature Sensor.

c. Item AC: Heated Oxygen Sensor (front)

d. Item BB: Barometric Pressure Sensor

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Are they operating properly?

YES : Go to Step 7.
NO :  Repair or replace it. Then confirm that the malfunction 

symptom is eliminated.

STEP 7. Using scan tool MB991958, check data list item 
AD: Heated oxygen sensor (rear).
(1) Start the engine and run at idle.
(2) Set scan tool MB991958 to the data reading mode for item 

AD, Heated Oxygen Sensor (rear).

a. Transaxle: 2nd
b. Drive with wide open throttle

c. Engine: 3,500 r/min

• The output voltages should be between 0.6 and 1.0 

volt.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES  : Go to Step 8.
NO :  Refer to, P0137 − Heated Oxygen Sensor (rear) 

Circuit Low Voltage 

P.13A-246

, DTC P0138 − Heated 

Oxygen Sensor (rear) Circuit High Voltage 

P.13A-254

, DTC P0139 − Heated Oxygen Sensor 

(rear) Circuit Slow Response 

P.13A-258

, DTC P0140 

− Heated Oxygen Sensor (rear) Circuit No Activity 

Detected 

P.13A-263

.

STEP 8. Check the fuel pressure.
Refer to Fuel Pressure Test 

P.13A-865

.

Q: Is the fuel pressure normal?

YES : Go to Step 9.
NO :  Repair or replace it. Then confirm that the malfunction 

symptom is eliminated.

STEP 9. Check the spark plugs.
Refer to GROUP 16, Ignition System − On-vehicle Service − 

Spark Plug Check And Cleaning 

P.16-39

.

Q: Are there any abnormalities?

YES : Replace the spark plug. Then confirm that the 

malfunction symptom is eliminated.

NO :  Go to Step 10.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-754

STEP 10. Check the ignition coil.
Refer to GROUP 16, Ignition System − On-vehicle Service − 

Ignition Coil Check 

P.16-37

.

Q: Are there any abnormalities?

YES : Replace the ignition coil. Then confirm that the 

malfunction symptom is eliminated.

NO :  Go to Step 11.

STEP 11. Check the compression pressure.
Refer to GROUP 11A, On-vehicle Service − Compression Pres-

sure Check 

P.11A-15

.

Q: Is the compression pressure normal?

YES : Go to Step 12.
NO :  Repair it. Then confirm that the malfunction symptom 

is eliminated.

STEP 12. Check the positive crankcase ventilation system.
Refer to GROUP 17, Emission Control − Positive Crankcase 

Ventilation System − Positive Crankcase Ventilation System 

Check 

P.17-72

.

Q: Is the positive crankcase ventilation system,?

YES : Go to Step 13.
NO :  Repair it. Then confirm that the malfunction symptom 

is eliminated.

STEP 13. Check the evaporative emission control system.
Refer to GROUP 17, Emission Control − Evaporative Emission 

Control System −Purge Control System Check (Purge Flow 

Check) 

P.17-75

.

Q: Is the purge control system normal?

YES : Go to Step 14.
NO :  Repair it. Then confirm that the malfunction symptom 

is eliminated.

STEP 14. Check the following items.
(1) Check the following items.

a. Check the injectors for fuel leakage.
b. Check if the injectors are clogged.

Q: Are there any abnormalities?

YES : Replace it. Then confirm that the malfunction 

symptom is eliminated.

Then confirm that the malfunction symptom is 

eliminated.

NO :  Replace the catalytic converter. Then confirm that the 

malfunction symptom is eliminated.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-755

Inspection procedure 19: Purge flow test of the evaporative emission canister failure

.

COMMENT

• The test fails when the purge line or purge port is 

clogged or if the evaporative emission purge 
solenoid fails.

.

TROUBLESHOOTING HINTS (The most 
likely causes for this case:)

• Purge line or purge port is clogged.
• Malfunction of the evaporative emission purge 

solenoid.

• Evaporative emission canister is clogged.

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.
• MB991827: USB Cable
• MB991910: Main Harness A

STEP 1. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).

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) Turn the ignition switch to the "ON" position.
(3) Read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is any DTC set?

YES : Refer to Diagnostic Trouble Code Chart 

P.13A-48

.

NO :  Refer to GROUP 17, Emission Control − Evaporative 

Emission Control System −Purge Control System 

Check (Purge Flow Check) 

P.17-75

.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-756

Inspection procedure 20: Pressure test of the evaporative system failure

.

COMMENT

• The test fails if there is a leak from the fuel tank or 

vapor line.

.

TROUBLESHOOTING HINTS (The most 
likely causes for this case:)

• Loose fuel tank filler tube cap.
• Broken seal in fuel tank, vapor line evaporative 

emission canister.

DIAGNOSIS

STEP 1. Check the evaporative emission purge solenoid.
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 normal?

YES : Go to Step 2.
NO :  Repair or replace it. Then confirm that the malfunction 

symptom is eliminated.

STEP 2. Check the evaporative emission ventilation 
solenoid.
Refer to GROUP 17, Emission Control − Evaporative Emission 

Canister And Fuel Tank Pressure Relief Valve − Inspection 

P.17-79

.

Q: Is the evaporative emission ventilation solenoid 

normal?
YES : Check the following items, and repair or replace the 

defective items.

a. Check for leaks from the vapor line or 

evaporative emission canister.

b. Check for leaks from the fuel tank.

Then confirm that the malfunction symptom is 

eliminated.

NO :  Repair or replace it. Then confirm that the malfunction 

symptom is eliminated.