Mitsubishi Galant. Manual - part 251

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-229

STEP 5. Check the spark plugs.

CAUTION

Do not attempt to adjust the gap of the platinum plug.
Cleaning of the platinum plug may result in damage to the
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) Check the plug gap and replace if the limit is exceeded.

Standard value: 1.0

−−−−

1.1 mm (0.039

−−−−

0.043 inch)

Limit: 1.3 mm (0.051 inch)

Q: Is the plug gap at the standard value?

YES : Go to Step 6.
NO : Replace the faulty spark plug. Then go to Step 13.

STEP 6. Check the spark plug cable.
(1) Check the cap and coating for cracks.
(2) Measure the resistance.

Limit: maximum 22 k

Ω

Q: Is the resistance normal?

YES : Refer to, INSPECTION PROCEDURE 32

−

Ignition

Circuit System(

P.13B-481

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

13.

STEP 7. Check the injector.
(1) Disconnect the injector connector.
(2) Measure the resistance between each injector side

connector terminal 1 and 2.

Standard value: 13

−−−−

16 ohm [at 20

°°°°

C (68

°°°°

F)]

Q: Is the resistance standard value?

YES : Go to Step 8.
NO : Replace the faulty injector. Then go to Step 13.

AKX00383

Platinum
tips

AKX00382

AK000618

AK000618 AE

CONNECTORS:B-17,B-19,B-21,B-22,B-25,B-30

B-25

B-19

B-22

B-30

B-17

B-21

AK000559

INJECTOR SIDE
CONNECTOR

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-230

STEP 8. Check connector B-17, B-19, B-21, B-22, B-25, B-
30 at injector and connector B-26 at injector intermediate
connector for damage.
Q: Is the connector in good condition?

YES : Go to Step 9.
NO : Repair or replace the faulty injector. Refer to GROUP

00E, Harness Connector Inspection (

P.00E-2

). Then

go to Step 13.

STEP 9. Check connector C-39 at PCM for damage.
Q: Is the connector in good condition?

YES : Go to Step 10.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection (

P.00E-2

). Then go to Step 13.

AK000618

AK000618 AE

CONNECTORS:B-17,B-19,B-21,B-22,B-25,B-30

B-25

B-19

B-22

B-30

B-17

B-21

AK000618

CONNECTOR:B-26

AK000280

CONNECTOR : C-39

PCM

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-231

STEP 10. Check for harness damage between injector
connector and PCM connector.

a. Check the harness wire between injector connector B-22

terminal 2 and PCM connector C-39 terminal 1 when
checking No.1 cylinder.

b. Check the harness wire between injector connector B-21

terminal 2 and PCM connector C-39 terminal 9 when
checking No.2 cylinder.

c. Check the harness wire between injector connector B-19

terminal 2 and PCM connector C-39 terminal 24 when
checking No.3 cylinder.

d. Check the harness wire between injector connector B-17

terminal 2 and PCM connector C-39 terminal 2 when
checking No.4 cylinder.

e. Check the harness wire between injector connector B-25

terminal 2 and PCM connector C-39 terminal 10 when
checking No.5 cylinder.

f. Check the harness wire between injector connector B-30

terminal 2 and PCM connector C-39 terminal 25 when
checking No.6 cylinder.

Q: Is the harness wire in good condition?

YES : Go to Step 11.
NO : Repair it. Then go to Step 13.

STEP 11. Check the following items.
(1) Check the following items, and repair or replace the

defective component.

a. Check for skipped timing belt teeth.
b. Check compression.

c. EGR valve failed.

Q: Are there any abnormalities?

YES : Go to Step 12.
NO : Repair or replace it. Then go to Step 13.

STEP 12. Replace the injector.
(1) Replace the injector.
(2) Carry out a test drive with the drive cycle pattern. Refer to,

Procedure 6

−

Other Monitor(

P.13B-4

(3) Check the diagnostic trouble code (DTC).

Q: Is the DTC P0300 is output?

YES : Replace the PCM. Then go to Step 13.
NO : The inspection is complete.

AK000618 AD

CONNECTORS:B-17,B-21,B-30

B-30

B-17

B-21

AK000280

CONNECTOR : C-39

PCM

AK000618 AD

CONNECTORS:B-17,B-21,B-30

B-30

B-17

B-21

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-232

STEP 13. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to,

Procedure 6

−

Other Monitor(

P.13B-4

(2) Check the diagnostic trouble code (DTC).

Q: Is the DTC P0300 is output?

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

DTC P0301: Cylinder 1 Misfire Detected, DTC P0302: Cylinder 2 Misfire Detected, DTC P0303: Cylinder
3 Misfire Detected, DTC P0304: Cylinder 4 Misfire Detected, DTC P0305: Cylinder 5 Misfire Detected,
DTC P0306 Cylinder 6 Misfire Detected

Misfire Detected Circuit

•

Refer to, DTC P0201,P0203,P0205

−

Injector

Circuit (

P.13B-212

•

Refer to, DTC P0202,P0204,P0206

−

Injector

Circuit (

P.13B-220

CIRCUIT OPERATION

•

Refer to, DTC P0201,P0203,P0205

−

Injector

Circuit (

P.13B-212

•

Refer to, DTC P0202,P0204,P0206

−

Injector

Circuit (

P.13B-220

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.

DTC SET CONDITIONS

Check Conditions

•

Five seconds or more have passed after the
engine was started.

•

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

•

Engine coolant temperature is higher than -10

(14

F).

•

Intake air temperature is higher than -10

C (14

F).

•

Barometric pressure is at between 77kPa (11psi)
and 106kPa (15psi).

•

Adaptive learning is complete for the vane which
generates a crankshaft position signal.

•

While the engine is running, excluding gear
shifting, deceleration, sudden acceleration/
deceleration and A/C compressor switching.

•

Vehicle speed is 2.5km/h (1.6mph) or more.

•

The throttle deviation is -0.059v/10ms to +0.059v/
10ms.

Judgement Criteria (change in the angular

acceleration of the crankshaft is used for
misfire detection).

•

Misfire has occurred in 4 or more of the last 200
revolutions [when the catalyst temperature is
higher than 950

C (1,742

F)].

•

Misfire has occurred in 20 or more of the last
1,000 revolutions (corresponding to 1.5 times the
limit of emission standard).

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

•

Ignition system related part(s) failed.

•

Low compression pressure.

•

Injector failed.

•

PCM failed.

DIAGNOSIS

Required Special Tools
MB991502: Scan Tool (MUT-II)

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