Mitsubishi Montero (2004+). Manual - part 240

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-447

STEP 6. Using scan tool MB991958, check data list item 14:
Throttle Position Sensor (sub).

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) Detach the intake air hose at the throttle body.
(4) Disconnect the connector of the throttle position sensor.
(5) Use test harness special tool (MB991658) to connect only

terminals No. 1, No. 2, No. 3, and No. 4.

(6) Set scan tool MB991958 to the data reading mode for item

14, Throttle Position Sensor (sub).

• Output voltage should be between 2.2 and 2.8 volts

when the throttle valve is fully closed with your finger.

• Output voltage should be 4.0 volts or more when the

throttle valve is fully open with your finger.

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

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

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

P.00-6

NO : Replace the PCM. Then go to Step 8.

STEP 7. Replace the throttle body assembly.
(1) Replace the throttle body assembly.
(2) Turn the ignition switch to the "ON" position.
(3) After the DTC has been deleted, read the DTC again.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC P0223 set?

YES : Replace the PCM. Then go to Step 8.
NO : The procedure is complete.

AK302970

MB991911

MB991824

MB991827

AK201173

THROTTLE
POSITION
SENSOR

B-05(B)

CONNECTOR: B-05

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-448

STEP 8. 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) After the DTC has been deleted, read the DTC again.
(4) Turn the ignition switch to the "LOCK"(OFF) position.
Q: Is DTC P0223 set?

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

DTC P0300: Random/Multiple Cylinder Misfire Detected

Random Misfire Circuit

• Refer to DTC P0335 − Crankshaft Position Sen-

sor Circuit.

P.13A-467

• Refer to DTC P0201 − P0206, Injector Circuit.

P.13A-421

CIRCUIT OPERATION

• Refer to DTC P0335 − Crankshaft Position Sen-

sor Circuit.

P.13A-467

• Refer to DTC P0201 − P0206, Injector Circuit.

P.13A-421

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

AK302970

MB991911

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-449

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).

• Volumetric efficiency is between 30 and 60 per-

cent.

• 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.

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

V/10 ms.

START

MONITORING

CONDITIONS

CALCULATE CRANKSHAFT

ANGULAR ACCELERATION (An)

An < TH

(Ne, v)

MISFIRE

CALCULATE PERCENT MISFIRE (R

)

END

YES

GOOD

WITHIN 1000rev

> SPECIFIED VALUE

MALFUNCTION

(EXCEED STD ×1.5)

GOOD

MALFUNCTION

(DAMAGE THE CAT.)

GOOD

> TH

(Ne, v)

CALCULATE PERCENT MISFIRE (R

)

WITHIN 200rev

Ne: ENGINE SPEED
v: VOLUMETRIC EFFICIENCY

AK302943

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-450

Judgement Criteria (change in the angular accel-

eration of the crankshaft is used for misfire
detection).

• Misfire has occurred more frequently than

allowed during the last 200 revolutions [when the
catalyst temperature is higher than 950

°C

(1742

°F)].

• Misfire has occurred in 20 or more of the last

1,000 revolutions (corresponding to 1.5 times the
limit of emission standard).

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: )

• Ignition system related part(s) failed.

• Poor crankshaft position sensor.

• Incorrect air/fuel ratio.

• Low compression pressure.

• Skipping of timing belt teeth.

• EGR system and EGR valve failed.

• PCM failed.

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, check data list item 22:
Crankshaft Position Sensor.

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) Start the engine and run at idle.
(3) Set scan tool MB991958 to the data reading mode for item

22, Crankshaft Position Sensor.

(4) Check the waveform of the crankshaft position sensor while

keeping the engine speed constant.

• The pulse width should be constant.

Q: Is the sensor operating properly?

YES : Go to Step 2.
NO : Refer to DTC P0335

− Crankshaft Position Sensor

Circuit Malfunction.

P.13A-467

AK302970

MB991911

MB991824

MB991827

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