Mitsubishi Montero Sport (2004+). Manual - part 256

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-437

STEP 11. Using the oscilloscope, check the injector.
(1) Disconnect the injector intermediate connector A-04 and 

connect the test harness special tool (MD998474) in 
between.

(2) Connect the oscilloscope probe to each injector 

intermediate connector terminal to oscilloscope each 
cylinder:

• Terminal No. 3 (green clip of the special tool) when 

checking No. 1 cylinder.

• Terminal No. 2 (white clip of the special tool) when 

checking No. 2 cylinder.

• Terminal No. 1 (blue clip of the special tool) when check-

ing No. 3 cylinder.

• Terminal No. 7 (yellow clip of the special tool) when 

checking No. 4 cylinder.

• Terminal No. 6 (red clip of the special tool) when check-

ing No. 5 cylinder.

• Terminal No. 5 (black clip of the special tool) when 

checking No. 6 cylinder.

NOTE: When measuring with the PCM side connector, con-
nect an oscilloscope probe to the each of the following ter-
minals.

.

•

PCM terminal No. 1 when checking No. 1 cylinder injec-
tor

•

PCM terminal No. 9 when checking No. 2 cylinder injec-
tor

•

PCM terminal No. 24 when checking No. 3 cylinder 
injector

•

PCM terminal No. 2 when checking No. 4 cylinder injec-
tor

•

PCM terminal No. 10 when checking No. 5 cylinder 
injector

•

PCM terminal No. 25 when checking No. 6 cylinder 
injector

(3) Start the engine and run at idle.
(4) Measure the waveform.

• The waveform should show a normal pattern similar to 

the illustration.

(5) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the waveform normal?

YES : It can be assumed that this malfunction is intermittent. 

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

P.00-7

.

NO :  Replace the PCM. Then go to Step 12.

AK102982 AB

OSCILLOSCOPE

INJECTOR
INTERMEDIATE
CONNECTOR

MD998474

1 2 3 4

5 6 7 8

AKX01557 AB

A

NORMAL  WAVEFORM

A:INJECTOR DRIVE TIME

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-438

STEP 12. 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: Are DTC P0201, P0202, P0203, P0204, P0205 and P0206 

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

Continue

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-439

13A

DTC P0300: Random/Multiple Cylinder Misfire Detected

.

Random Misfire Circuit

• Refer to DTC P0335 − Crankshaft Position Sen-

sor Circuit. 

P.13A-452

 

• Refer to DTC P0201 − P0206, Injector Circuit. 

P.13A-428

 

.

CIRCUIT OPERATION

• Refer to DTC P0335 − Crankshaft Position Sen-

sor Circuit. 

P.13A-452

 

• Refer to DTC P0201 − P0206, Injector Circuit. 

P.13A-428

 

.

TECHNICAL DESCRIPTION

• If a misfire occurs while the engine is running, the 

engine speed changes for an instant.

• The PCM checks for such changes in engine 

speed.

.

DESCRIPTIONS OF MONITOR METHODS
Monitor angular acceleration of crankshaft and 

detect malfunction when negative variation of the 
angular acceleration is large.

.

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)

• Not applicable

Sensor (The sensor below is determined to be 

normal)

• Camshaft position sensor

• 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-440

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• Engine speed is between 440 and 6,000 r/min.

• Engine coolant temperature is higher than −10°C 

(14

°F).

• Barometric pressure is higher than 76 kPa (22.4 

in.Hg).

• Adaptive learning is complete for the vane which 

generates a crankshaft position signal.

• While the engine is running, excluding gear shift-

ing, deceleration, sudden acceleration/decelera-
tion and A/C compressor switching and fuel 
shut-off operation. 

• The throttle deviation is −0.06 volt/10 ms to +0.06 

volt/10 ms.

START

MONITORING

CONDITIONS

CALCULATE CRANKSHAFT

ANGULAR ACCELERATION (An)

An < TH

MF

 (Ne,   v)

MISFIRE

CALCULATE PERCENT MISFIRE (R

MF

)

END

NO

NO

NO

NO

NO

NO

YES

YES

YES

YES

YES

YES

GOOD

WITHIN 1000rev

R

MF

 > SPECIFIED VALUE

MALFUNCTION

(EXCEED STD  ×1.5)

GOOD

MALFUNCTION

(DAMAGE THE CAT.)

GOOD

R

MF

 > TH

CD

 (Ne,   v)

CALCULATE PERCENT MISFIRE (R

MF

)

WITHIN 200rev

Ne: ENGINE SPEED
   v: VOLUMETRIC EFFICIENCY

AK204053