Mitsubishi Eclipse. Manual - part 223

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-385

STEP 9. Using the oscilloscope, check the injector.
(1) Disconnect the injector connector B-01 <No.1 cylinder> or

B-02 <No.2 cylinder> or B-05 <No.3 cylinder> or B-06
<No.4 cylinder> and connect the test harness special tool
(MB991348) in between. (All terminals should be
connected.)

(2) Connect the oscilloscope probe to the injector side

connector terminal No. 2.
NOTE: When measuring with the ECM or PCM side con-
nector, connect an oscilloscope probe to the each of the fol-
lowing terminals.

•

ECM terminal No. 1 or PCM terminal No. 1 when check-
ing No. 1 cylinder.

•

ECM terminal No. 14 or PCM terminal No. 9 when
checking No. 2 cylinder.

•

ECM terminal No. 2 or PCM terminal No. 24 when
checking No. 3 cylinder.

•

ECM terminal No. 15 or PCM terminal No. 2 when
checking No. 4 cylinder.

(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.00-6

NO : Replace the ECM or PCM. Then go to Step 10.

STEP 10. 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-5

(2) Check the diagnostic trouble code (DTC).
Q: Are DTC P0201, P0202, P0203 and P0204 set?

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

AK102980

1 2

INJECTOR
CONNECTOR

MB991348

OSCILLOSCOPE

AKX01557 AB

NORMAL WAVEFORM

A:INJECTOR DRIVE TIME

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-386

DTC P0300: Random/Multiple Cylinder Misfire Detected

Random Misfire Circuit

• Refer to, DTC P0201 − P0204 Injector Circuit

Malfunction

P.13A-377

CIRCUIT OPERATION

• Refer to, DTC P0201 − P0204 Injector Circuit

Malfunction

P.13A-377

TECHNICAL DESCRIPTION

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

engine speed changes for an instant.

• The ECM <M/T> or PCM <A/T> 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) <2.4L>

13A-387

DTC SET CONDITIONS

Logic Flow Chart

Check Conditions

• Engine speed is between 500 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.

• 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

(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

AK204053

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-388

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-ll DRIVE CYCLE PATTERN
Refer to Diagnostic Function

− OBD-ll Drive Cycle −

Procedure 6

− Other Monitor

P.13A-5

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

• Ignition system related part(s) failed.

• Low compression pressure.

• Skipping of timing belt teeth.

• Harness damage in injector circuit, or connector

damage.

• Injector failed.

• ECM failed. <M/T>

• PCM failed. <A/T>

DIAGNOSIS

Required Special Tools:

• MB991958 (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.

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

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

− Crankshaft Position Sensor

Circuit Malfunction

P.13A-409

AK300810

MB991911

16-PIN

MB991827

MB991824

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