Mitsubishi Montero (2004+). Manual - part 291

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-651

NOTE: Check harness after checking intermediate connectors
E-113, D-111 and F-07. If intermediate connectors are dam-
aged, repair or replace them. Refer to GROUP 00E, Harness
Connector Inspection

P.00E-2

. Then go to Step 6.

Q: Is the harness wire in good condition?

YES : Go to Step 5.
NO : Repair it. Then go to Step 6.

STEP 5. Retest the system.
(1) Carry out a test drive with the drive cycle pattern. Refer to

Diagnostic Function

− OBD-II Drive Cycle − Procedure 6 −

Other Monitor

P.13A-4

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0461 set?

YES : Replace the PCM. Then go to Step 6.
NO : It can be assumed that this malfunction is intermittent.

Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

P.00-6

STEP 6. Perform the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to

Diagnostic Function

− OBD-II Drive Cycle − Procedure 6 −

Other Monitor

P.13A-4

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0461 is set?

YES : Repeat the troubleshooting.
NO : The procedure is complete.

DTC P0506: Idle Control Sytem RPM Lower Than Expected

TECHNICAL DESCRIPTION

• The amount of air taken in during idling is regu-

lated by the opening and closing of the throttle
valve.

• The PCM checks the difference between the

actual engine speed and the target engine speed.

DESCRIPTIONS OF MONITOR METHODS
Difference between actual and target idle speed is

over the specified value.

MONITOR EXECUTION
Continuous

MONITOR EXECUTION CONDITIONS (Other
monitor and Sensor)

Other Monitor (There is no temporary DTC stored

in memory for the item monitored below)

• Misfire monitor

• Exhaust gas recirculation (EGR) system monitor

• Fuel system monitor

Sensor (The sensor below is determined to be

normal)

• Volume airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

• Barometric pressure sensor

• Throttle position sensor

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-652

DTC SET CONDITIONS

Logic Flow Chart

Check Conditions

• Under the closed loop idle speed control.

• The engine coolant temperature is more than

°C (171°F).

• Battery positive voltage is higher than 10 volts.

• Power steering pressure switch: "OFF".

• Volumetric efficiency is lower than 40 percent.

• Barometric pressure is higher than 76 kPa (22.4

in.Hg).

• Intake air temperature is higher than −10°C

(14

°F).

• 60 seconds have elapsed from the start of the

previous monitoring.

• Target throttle actuator control motor position is

more than 255 steps.

Judgment Criteria

• The actual idle speed is more than 100 r/min

lower than the target idle speed for 12 seconds.

OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function

− OBD-II Drive Cycle −

Procedure 6

− Other Monitor

P.13A-4

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

• Throttole valve area is dirty.

• PCM failed.

END

YES

MALFUNCTION

GOOD

START

CALCULATE

MONITORING

CONDITIONS

Ne = (ACTUAL-Ne) - (TARGET-Ne)

Ne: ENGINE SPEED

Ne < -100 r/min OR

> 200 r/min

HAVE 10secs PASSED?

AK302956

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-653

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) Set scan tool MB991958, read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the diagnostic trouble code other than P0506 set?

YES : Refer to Diagnostic Trouble Code Chart

P.13A-26

NO : Go to Step 2.

STEP 2. Check the throttle body. (throttle valve area)
Q: Is the throttle valve area dirty?

YES : Perform cleaning. Refer to throttle body (throttle valve

area) cleaning

P.13A-993

. Then go to Step 4.

NO : Go to Step 3.

STEP 3. Check the trouble symptoms.
(1) Carry out a test drive with the drive cycle pattern. Refer to

Diagnostic Function

− OBD-II Drive Cycle − Procedure 6 −

Other Monitor

P.13A-4

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0506 set?

YES : Replace the PCM. Then go to Step 4.
NO : It can be assumed that this malfunction is intermittent.

Refer to GROUP 00, How to Use
Troubleshooting/Inspectuin Service Points

P.00-6

AK302970

MB991911

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-654

STEP 4. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to

Diagnostic Function

− OBD-II Drive Cycle − Procedure 6 −

Other Monitor

P.13A-4

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0506 set?

YES : Retry the troubleshooting.
NO : The inspection is complete.

DTC P0507: Idle Control Sytem RPM Higher Than Expected

TECHNICAL DESCRIPTION

• The amount of air taken in during idling is regu-

lated by the opening and closing of the throttle
valve.

• The PCM checks the difference between the

actual engine speed and the target engine speed.

DESCRIPTIONS OF MONITOR METHODS
Difference between actual and target idle speed is

over the specified value.

MONITOR EXECUTION
Continuous

MONITOR EXECUTION CONDITIONS (Other
monitor and Sensor)

Other Monitor (There is no temporary DTC stored

in memory for the item monitored below)

• Misfire monitor

• Exhaust gas recirculation (EGR) system monitor

• Fuel system monitor

Sensor (The sensor below is determined to be

normal)

• Volume airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

• Barometric pressure sensor

• Throttle position sensor

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