Mitsubishi Montero Sport (2004+). Manual - part 342

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-781

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

Reference Table 

P.13A-839

.

a. Item 39: Right Bank Heated Oxygen Sensor (front)
b. Item 11: Left Bank Heated Oxygen Sensor (front)

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

1.0 volt while idling 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 8.
NO :  Go to Step 7.

STEP 7. Check the fuel pressure.
Refer to On-vehicle Service 

− Fuel Pressure Test 

P.13A-884

.

Q: Is the fuel pressure normal?

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

defective items.

a. Vacuum leak.

• Broken intake manifold gasket.

• Broken air intake hose.

• Broken vacuum hose.

• Positive crankcase ventilation valve does 

not operate.

b. Injector clogged.

Then confirm that the malfunction symptom is 

eliminated.

NO :  Repair or replace. Then confirm that the malfunction 

symptom is eliminated.

AK303629AB

MB991911

MB991827

MB991824 

16-PIN

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-782

STEP 8. Check the fuel pressure.
Refer to On-vehicle Service 

− Fuel Pressure Test 

P.13A-884

.

Q: Is the fuel pressure normal?

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

defective items.

a. Check the ignition coil, spark plugs, spark plug 

cables.

b. Check compression pressure.

c. Check the fuel filter or fuel line for clogging.

d. Broken air intake hose.
e. Clogged air cleaner.

f. Clogged exhaust system.

Then confirm that the malfunction symptom is 

eliminated.

NO :  Repair or replace. Then confirm that the malfunction 

symptom is eliminated.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-783

INSPECTION PROCEDURE 19: Surge.

.

COMMENT

• Defective ignition system, abnormal air/fuel ratio, 

etc. are suspected.

.

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

• Malfunction of the ignition system.

• Malfunction of air/fuel ratio control system.

• Malfunction of the EGR vacuum regulator sole-

noid valve system.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (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 "ON" position.
Q: Is DTC set?

YES : Refer to Diagnostic Trouble Code Chart 

P.13A-26

.

NO :  Go to Step 2.

AK303629AB

MB991911

MB991827

MB991824 

16-PIN

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-784

STEP 2. Using scan tool MB991958, check actuator test 
items 01, 02, 03, 04, 05, 06: Injector.
(1) Turn the ignition switch to the "ON" position.
(2) Check following items in the actuator test. Refer to Actuator 

Test Reference Table 

P.13A-854

.

a. Items 01, 02, 03, 04, 05, 06: Injector.

(3) Turn the ignition switch to the "ON" position.
Q: Is the actuator operating properly?

YES : Go to Step 3.
NO :  Refer to DTC P0201, P0202, P0203, P0204, P0205, 

P0206 

− Injector Circuit 

P.13A-428

. 

STEP 3. Check the ignition timing.
Refer to GROUP 11A, On-vehicle Service 

− Ignition Timing 

Check 

P.11A-9

.

Q: Is the ignition timing normal?

YES : Go to Step 4.
NO :  Check that the crankshaft position sensor and timing 

belt cover are in the correct position. Then confirm 
that the malfunction symptom is eliminated. 

AK303629AB

MB991911

MB991827

MB991824 

16-PIN