Mitsubishi Eclipse. Manual - part 331

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-817

STEP 8. Using scan tool MB991958, check data list item 11: 
Heated oxygen sensor (front).
(1) Start the engine and run at idle.
(2) Set scan tool MB991958 to the data reading mode for item 

11, Heated Oxygen Sensor (front).

• Voltage should fluctuate between 0 − 0.4 volt and 0.6 − 

1.0 volt while after the engine has been warmed.

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

YES : Go to Step 9.
NO :  Go to Step 11.

STEP 9. Check the EGR system.
Refer to GROUP 17, Emission Control System 

− EGR System 

Check 

P.17-112

.

Q: Is the EGR system normal?

YES : Go to Step 10.
NO :  Repair or replace. Then confirm that the malfunction 

symptom is eliminated.

AK300810

AB

MB991911

16-PIN

MB991827

MB991824 

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-818

STEP 10. Using scan tool MB991958, check data list item 
59: Heated oxygen sensor (rear).

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) Start the engine and run at idle.
(3) Set scan tool MB991958 to the data reading mode for item 

59, Heated Oxygen Sensor (rear).

• Average voltage should be 0.6 volt or less, when idling.

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

YES : Go to Step 12.
NO :  Replace the heated oxygen sensor (front). Then 

confirm that the malfunction symptom is eliminated.

STEP 11. Check the fuel pressure.
Refer to, Fuel Pressure Test 

P.13A-929

.

Q: Is the fuel pressure normal?

YES : Go to Step 12.
NO :  Repair or replace. Then confirm that the malfunction 

symptom is eliminated.

STEP 12. Check the following items.
(1) Check the following items, and repair or replace the 

defective items.

a. Check the injectors for fuel leakage.
b. Check the ignition coil, spark plugs, spark plug cables.

c. Check compression pressure.

d. Check the positive crankcase ventilation system.
e. Check the evaporative emission system.

(2) Then check the malfunction symptom.
Q: Is the malfunction symptom is eliminated?

YES : The check is completed.
NO :  Replace the catalytic converter. Then confirm that the 

malfunction symptom is eliminated.

AK300810

AB

MB991911

16-PIN

MB991827

MB991824 

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-819

INSPECTION PROCEDURE 24: 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 (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991911: Main Harness B

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 DTC set?

YES : Refer to, Diagnostic Trouble Code Chart 

P.13A-24

.

NO :  Refer to GROUP 17, Emission Control System 

− 

Purge Control System Check (Purge Flow Check) 

P.17-106

.

AK300810

AB

MB991911

16-PIN

MB991827

MB991824 

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-820

INSPECTION PROCEDURE 25: 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 System 

− Evaporative 

Emission Purge Solenoid Check 

P.17-107

.

Q: Is the evaporative emission purge solenoid normal?

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

symptom is eliminated.

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

− Evaporative 

Emission Ventilation Solenoid Check 

P.17-109

.

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. Then confirm that the malfunction 

symptom is eliminated.