Mitsubishi Montero Sport (2004+). Manual - part 346

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-797

STEP 16. 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 eliminated?

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

malfunction symptom is eliminated.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-798

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: 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 "LOCK" (OFF) position.
Q: Is DTC set?

YES : Refer to Diagnostic Trouble Code Chart 

P.13A-26

.

NO :  Refer to GROUP 17, Emission Control System 

− 

Purge Control System Check (Purge Flow Check) 

P.17-108

.

AK303629AB

MB991911

MB991827

MB991824 

16-PIN

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-799

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.17-109

.

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.17-110

.

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.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-800

INSPECTION PROCEDURE 26: Incorrect Idle Speed When the A/C is Operating (A/C Switch 2 Signal)

.

CIRCUIT OPERATION

• The PCM increases the engine idle speed by 

driving the IAC motor when the automatic com-
pressor-ECU sends a "A/C on" signal to the mod-
ule.

• The automatic compressor-ECU detects how the 

air conditioning is applying load to the engine, 
and converts the information to a voltage signal 
(High voltage = low load, Low voltage = high 
load). This voltage signal is called "A/C switch 2 

signal." The PCM receives this A/C switch 2 sig-
nal from the automatic compressor-ECU through 
terminal No. 61, and determines the idle-up 
speed according to the high or low air condition-
ing load.

.

TROUBLESHOOTING HINTS (The most likely 
causes for this code to be set are: ) 

• Malfunction of the A/C control system.

• Open or shorted circuit, or improper connector 

contact.

• PCM failed. 

YELL

OW

-WHITE

YELL

OW

-WHITE

AK102611

3

61

AUTOMATIC COMPRESSOR-ECU

POWERTRAIN CONTROL
MODULE (PCM)

1

9

2 3

4

5 6

7 8

10 11 12 13 14 15 16 17 18 19

C-72
MU801559

47

41

42 43

48 49 50 51 52 53 54 55 56 57

46

45

44

58

59

60 61 62 63

64 65 66

C-90
(MU803781)

AK200043 AB

CONNECTOR: C-72

C-72(B)

DEDICATED
FUSES

AK103738AC

CONNECTOR: C-90

PCM

C-90(GR)