Mitsubishi Montero (2004+). Manual - part 346

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-871

• 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 the DTC set?

YES : Refer to Diagnostic Trouble Code Chart 

P.13A-26

.

NO :  Go to Step 2.

STEP 2. 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-950

.

a. Item 21: Engine Coolant Temperature Sensor.

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

YES : Refer to On-vehicle Service 

− Clean the throttle valve 

area 

P.13A-993

.

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

symptom is eliminated.

INSPECTION PROCEDURE 11: When the engine is cold, it stalls at idle (die out).

.

COMMENT

• In such cases as the above, the air/fuel mixture 

may be inappropriate when the engine is cold.

.

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

• Malfunction of the electronic control throttle valve 

system.

• Malfunction of the throttle body.

• Malfunction of the injector system.

• Malfunction of the ignition system.

AK302970

AB

MB991911

MB991824

MB991827

AK302970

AB

MB991911

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-872

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991911: Main Harness B

STEP 1. Check if the battery terminal is disconnected.
Q: Has the battery terminal been disconnected lately?

YES : Start the engine and let it run at idle for approximate 

10 minutes after engine warm up. Then, if a 
malfunction occurs, go to Step 2.

NO :  Go to Step 2.

STEP 2. 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 the DTC set?

YES : Refer to Diagnostic Trouble Code Chart 

P.13A-26

.

NO :  Go to Step 3.

STEP 3. Checking by operating the accelerator pedal.
Q: Does the engine stall right after the accelerator pedal is 

released?
YES : Refer to On-vehicle Service 

− Clean the throttle valve 

area 

P.13A-993

.

NO :  Go to Step 4.

STEP 4. Check the engine idling.
Q: Is the idling good enough after warm up?

YES : Go to Step 5.
NO :  Refer to INSPECTION PROCEDURE 8 

− Unstable 

Idle (Rough Idle, Hunting) 

P.13A-865

.

AK302970

AB

MB991911

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-873

STEP 5. Using scan tool MB991958, check actuator test 
items 01, 02, 03, 04, 05, 06: Injector.

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) Check following items in the actuator test. Refer to Actuator 

Test Reference Table 

P.13A-966

. 

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

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

YES : Go to Step 6.
NO :  Refer to DTC P0201, P0202, P0203, P0204, P0205, 

P0206 

− Injector Circuit 

P.13A-421

.

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-950

.

a. Item 21: Engine Coolant Temperature Sensor.

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

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

symptom is eliminated.

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

− Fuel Pressure Test 

P.13A-995

.

Q: Is the fuel pressure normal?

YES : Go to Step 8.
NO :  Repair or replace it. Then confirm that the malfunction 

symptom is eliminated.

AK302970

AB

MB991911

MB991824

MB991827

AK302970

AB

MB991911

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-874

STEP 8. Check the ignition timing.
Refer to GROUP 11A, On-vehicle Service 

− Ignition Timing 

Check 

P.11A-7

.

Q: Is the ignition timing 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 engine oil viscosity.
d.Check the EGR valve.

Then confirm that the malfunction symptom is 

eliminated. 

NO :  Check that the crankshaft position sensor and timing 

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

INSPECTION PROCEDURE 12: When the Engine Is Hot, It Stalls at Idle (Die Out).

.

COMMENT

• In cases such as the above, the ignition system, 

air/fuel mixture, electronic control throttle valve 
system or compression pressure may be faulty. In 
addition, if the engine suddenly stalls, the cause 
may also be a loose connector.

.

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

• Malfunction of the ignition system.

• Malfunction of air/fuel ratio control system.

• Malfunction of the electronic control throttle valve 

system.

• Malfunction of the EGR valve. 

• Vacuum leak.

• Improper connector contact.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991911: Main Harness B

STEP 1. Check if the battery terminal is disconnected.
Q: Has the battery terminal been disconnected lately?

YES : Start the engine and let it run at idle for approximate 

10 minutes after engine warm up. Then, if a 
malfunction occurs, go to Step 2.

NO :  Go to Step 2.