Mitsubishi Galant (2004+). Manual - part 1217

 

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Mitsubishi Galant (2004+). Manual - part 1217

 

 

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-561

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 

(1,742

°F)].

or

• Misfire has occurred in 17 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.13B-5

.

.

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

• Ignition system related part(s) failed.

• Low compression pressure.

• PCM failed.

DIAGNOSIS

STEP 1. Check the No.2 cylinder ignition coil spark.
(1) Remove the No.2 cylinder ignition coil.

(2) Remove the No.2 cylinder spark plug and connect to the 

ignition coil.

(3) Ground the No.2 cylinder spark plug side electrode 

securely.

• When the engine is cranked, the spark plug should 

spark.

Q: Did it spark?

YES : Go to Step 3.
NO :  Go to Step 2.

STEP 2. Check the No.2 cylinder spark plugs.

CAUTION

Do not attempt to adjust the gap of the iridium plug. Clean-
ing of the iridium plug may result in damage to the iridium 
and platinum tips. Therefore, if carbon deposits must be 
removed, use a plug cleaner and complete cleaning within 
20 seconds to protect the electrode. Do not use a wire 
brush.
Check the plug gap and replace if the limit is exceeded.

Standard value: 0.7 

 0.8 mm (0.028  0.031 inch)

Limit: 1.0 mm (0.039 inch)

Q: Is the plug gap at the standard value?

YES : Refer to, INSPECTION PROCEDURE 31 

− Ignition 

Circuit System 

P.13B-1079

.

NO :  Replace the No.2 cylinder spark plug. Then go to Step 

5.

STEP 3. Check the compression.

Refer to GROUP 11A, On-Vehicle Service 

− Compression 

Pressure Check 

P.11A-16

.

Q: Are there any abnormalities?

YES : Repair or replace it. Then go to Step 5.
NO :  Go to Step 4.

AKX00432

SPARK PLUG

AB

AKX01327AB

IRIDIUM
TIP

PLATINUM
TIP

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-562

STEP 4. 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.13B-5

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0302 set?

YES : Replace the PCM. Then go to Step 5.
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 5. 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.13B-5

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0302 set?

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

DTC P0303: Cylinder 3 Misfire Detected

CAUTION

If DTC P0303 has been set, TCL related DTC 
U1120 is also set. After P0303 has been diag-
nosed, don't forget to erase DTC U1120.

.

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

• 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) <3.8L ENGINE>

13B-563

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• Engine speed is between 440 and 6,200 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 at between 30 and 60 

percent.

• 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

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

(CATALYTIC CONVERTER

IS DAMAGED.)

GOOD

R

MF

 > TH

CD

 (Ne,   v)

CALCULATE PERCENT MISFIRE (R

MF

)

WITHIN 200rev

Ne: ENGINE SPEED
   v: VOLUMETRIC EFFICIENCY

AK204053

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-564

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 

(1,742

°F)].

or

• 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.13B-5

.

.

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

• Ignition system related part(s) failed.

• Low compression pressure.

• PCM failed.

DIAGNOSIS

STEP 1. Check the No.3 cylinder ignition coil spark.
(1) Remove the No.3 cylinder intake manifold.
(2) Remove the No.3 cylinder ignition coil.

(3) Remove the spark plug and connect to the No.3 cylinder 

ignition coil.

(4) Ground the spark plug side electrode securely.

• When the engine is cranked, the spark plug should 

spark.

Q: Did it spark?

YES : Go to Step 3.
NO :  Go to Step 2.

STEP 2. Check the No.3 cylinder spark plugs.

CAUTION

Do not attempt to adjust the gap of the iridium plug. Clean-
ing of the iridium plug may result in damage to the iridium 
and platinum tips. Therefore, if carbon deposits must be 
removed, use a plug cleaner and complete cleaning within 
20 seconds to protect the electrode. Do not use a wire 
brush.
(1) Remove the intake manifold.
(2) Check the plug gap and replace if the limit is exceeded.

Standard value: 0.7 

 0.8 mm (0.028  0.031 inch)

Limit: 1.0 mm (0.039 inch)

Q: Is the plug gap at the standard value?

YES : Refer to, INSPECTION PROCEDURE 31 

− Ignition 

Circuit System 

P.13B-1079

.

NO :  Replace the No.3 cylinder spark plug. Then go to Step 

5.

AKX00432

SPARK PLUG

AB

AKX01327AB

IRIDIUM
TIP

PLATINUM
TIP

 

 

 

 

 

 

 

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