Mitsubishi Lancer Evolution X. Manual - part 325

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-365

STEP 9. Check for harness damage between turbocharger 
wastegate solenoid 2 connector A-08 (terminal No. 2) and 
ECM connector B-09 (terminal No. 53).
NOTE: Check harness after checking intermediate connector 
A-13. If intermediate connector is damaged, repair or replace it. 
Refer to GROUP 00E, Harness Connector Inspection 

P.00E-2

. 

Then go to Step 10.
Q: Is the harness wire in good condition?

YES : Replace the ECM. When the ECM is replaced, 

register the ID code. Refer to GROUP 42B, ID Code 
Registration Necessity Judgment Table <Vehicles 
with KOS> 

P.42B-11

 or GROUP 42C, ID Codes 

Registration Judgment Table <Vehicles with WCM> 

P.42C-9

. Then go to Step 10.

NO :  Repair it. 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 − Pattern 23 

P.13A-9

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0247 set?

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

DTC P0300: Random/Multiple Cylinder Misfire Detected

.

TECHNICAL DESCRIPTION

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

engine speed changes for an instant.

• The ECM 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
• Mass 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-366

DTC SET CONDITIONS

Logic Flow Chart

Check Conditions

• Engine speed is between 438 and 7,000 r/min.
• Engine coolant temperature is higher than −10° C 

(14° F).

• Barometric pressure is higher than 76 kPa (22.4 

in.Hg).

• The engine load is with in the positive torque 

load.

Calculate crankshaft

angular acceleration (An)

Misfire

Calculate percent misfire (R

MF

)

End

No

No

No

No

No

No

Yes

Good

Within 1000rev

Malfunction

(exceed std × 1.5)

Good

Malfunction (catalytic

converter is damaged.)

Good

Calculate percent misfire (R

MF

)

Within 200rev

Ne
Ec     : Charge efficiency
TH

MF

 : Threshold value for misfire

TH

CD

 : Threshold value for catalyst damage

AK800585

Start

Yes

Yes

Yes

Yes

Yes

Monitoring
conditions

An < TH

MF

 (Ne, Ec)

R

MF

 

>= specified value

R

MF

 >= TH

CD

 (Ne, Ec)

: Engine speed

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-367

• Adaptive learning is complete for the vane which 

generates a crankshaft position signal.

• While the engine is running, excluding rough road 

driving <M/T>, sudden acceleration/deceleration 
and fuel shut-off operation.

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 1,000° C 

(1,832° F)].

or

• Misfire has occurred in 2.0 percent or more of the 

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

.

FAIL-SAFE AND BACKUP FUNCTION

• The supply of fuel to the misfiring cylinder can 

possibly be cut.

.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function − OBD-II Drive Cycle − 

Pattern 14 

P.13A-9

.

.

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.
• ECM failed. 

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: V.C.I.
• MB991827: USB Cable
• MB991910: Main Harness A

STEP 1. Using scan tool MB991958, check data list item 2: 
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 

2, Crankshaft Position Sensor.

• The tachometer and engine speed indicated on the scan 

tool should match.

(4) 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 

P.13A-389

.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-368

STEP 2. Using scan tool MB991958, check data list item 26: 
Long-Term Fuel Trim.
(1) Start the engine and run at idle.
(2) Set scan tool MB991958 to the data reading mode for item 

26, Long-Term Fuel Trim.

• The fuel trim should be between −12.5 and +12.5 per-

cent when the engine is 2,500 r/min (during closed loop) 
after the engine is warmed.

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

YES : Go to Step 3.
NO :  Refer to DTC P0171 − System too Lean 

P.13A-267

, 

DTC P0172 − System too Rich 

P.13A-273

.

STEP 3. Using scan tool MB991958, check data list item 28: 
Short-Term Fuel Trim.
(1) Start the engine and run at idle.
(2) Set scan tool MB991958 to the data reading mode for item 

28, Short-Term Fuel Trim.

• The fuel trim should be between −25 and +25 percent 

when the engine is 2,500 r/min (during closed loop) after 
the engine is warmed.

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

YES : Go to Step 4.
NO :  Refer to DTC P0171 − System too Lean 

P.13A-267

, 

DTC P0172 − System too Rich 

P.13A-273

.

STEP 4. Visual check of ignition spark.
(1) Remove the spark plug and install it to the ignition coil.
(2) Connect the ignition coil connector.
(3) Remove all injector connector.
(4) At the engine start, check each spark plug produces a 

spark.

Q: Did it spark?

YES : Go to Step 6.
NO :  Go to Step 5.

STEP 5. Check the spark plugs.
Refer to GROUP 16, Ignition System − On-vehicle Service − 

Spark Plug Check And Cleaning.

P.16-38

Q: Is the spark plug normal?

YES : Refer to Symptom Procedures 26 − Ignition Circuit 

System 

P.13A-808

.

NO :  Replace the faulty spark plug. Then go to Step 8.

AK704268 AB

Spark plug