Mitsubishi Galant. Manual - part 298

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-417

STEP 9. Check connector B-19 or B-22 or B-25 at right
bank injector for damage.
(1) Check the injector connector, which deviated from the

standard value listed in Step 7.

Q: Is the connector in good condition?

YES : Repair harness wire between injector intermediate

connector and right bank injector connector because
of harness damage.Then confirm that the malfunction
symptom is eliminated.

NO : Repair or replace it.Refer to GROUP 00E, Harness

Connector Inspection(

P.00E-2

).Then confirm that the

malfunction symptom is eliminated.

STEP 10. Check connector B-26 at the injector
intermediate connector for damage.
Q: Is the connector in good condition?

YES : Go to Step 11.
NO : Repair or replace it.Refer to GROUP 00E, Harness

Connector Inspection(

P.00E-2

).Then confirm that the

malfunction symptom is eliminated.

STEP 11. Check connector B-17, B-21, B-30 at the left bank
injector for damage.
Q: Is the connector in good condition?

YES : Go to Step 12.
NO : Repair or replace it.Refer to GROUP 00E, Harness

Connector Inspection(

P.00E-2

).Then confirm that the

malfunction symptom is eliminated.

AK000618AC

CONNECTORS:B-19,B-22,B-25

B-25

B-19

B-22

AK000618

CONNECTOR:B-26

AK000618 AD

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

B-30

B-17

B-21

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-418

STEP 12. Check the connector C-39 at the PCM for
damage.
Q: Is the connector in good condition?

YES : Go to Step 13.
NO : Repair or replace it.Refer to GROUP 00E, Harness

Connector Inspection(

P.00E-2

).Then confirm that the

malfunction symptom is eliminated.

STEP 13. 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 injector.

b. Check the harness wire between injector connector B-

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

c. Check the harness wire between injector connector B-

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

d. Check the harness wire between injector connector B-

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

e. Check the harness wire between injector connector B-

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

f. Check the harness wire between injector connector B-

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

Q: Is the harness wire in good condition?

YES : Check the following items, and repair or replace the

defective items.

a. Check the ignition coil, spark plugs, spark plug

cables.

b. Check if the injectors are clogged.

c. Check the compression pressure.

d. Check if the foreign materials (water,

kerosene, etc.) got into fuel.

Then confirm that the malfunction symptom is

eliminated.

NO : Repair it.Then confirm that the malfunction symptom

is eliminated.

AK000280

CONNECTOR : C-39

PCM

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

AK000280

CONNECTOR : C-39

PCM

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-419

INSPECTION PROCEDURE 8: Unstable Idle (Rough Idle, Hunting).

COMMENT

•

In cases such as the above, the cause is
probably the air/fuel mixture or idle air control
motor. Other systems affecting idle quality
include the ignition system and compression.

TROUBLESHOOTING HINTS (The most likely
causes for this case:)

•

Malfunction of the ignition system.

•

Malfunction of air/fuel ratio control system.

•

Malfunction of the IAC system.

•

Malfunction of the evaporative emission purge
solenoid system.

•

Poor compression pressure.

•

Vacuum leak.

•

Malfunction of the EGR solenoid system.

DIAGNOSIS

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

STEP 1. Check if the battery terminal is disconnected

Q: Has the battery terminal been disconnected lately?

YES : Start the engine and let it run at idle for approximate

10 minutes after engine warm up.Then, if a
malfunction occurs, go to Step 2.

NO : Go to Step 2.

STEP 2. Using scan tool MB991502, read the diagnostic
trouble code (DTC).

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch is to the "LOCK" (OFF) position before
connecting or disconnecting scan tool MB991502.
(1) Connect scan tool MB991502 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC is output?

YES : Refer to, Diagnostic Trouble Code Chart(

P.13B-19

NO : Go to Step 3.

STEP 3. Check the engine idling state.

Q: Is it hunting remarkably?

YES : Go to Step 4.
NO : Go to Step 5.

AC003081 AB

16 PIN

MB991502

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-420

STEP 4. Check the following items.
(1) Carry out the following cleaning.

a. Clean the throttle valve area (refer to

P.13B-520

(2) After cleaning, confirm that the malfunction symptom is

eliminated.

Q: Is the malfunction symptom resolved?

YES : The check is completed.
NO : Check the following items, and repair or replace the

defective items.

a. Broken intake manifold gasket.
b. Broken air intake hose.

c. Broken vacuum hose.

d. Positive crankcase ventilation valve does not

operate.

Then confirm that the malfunction symptom is

eliminated.

STEP 5. Check the idle air control (IAC) motor operation
sound.
(1) Check that the engine coolant temperature is 20

C (68

or below.

NOTE: Disconnecting the engine coolant temperature
sensor connector and connecting the harness side of the
connector to another engine coolant temperature sensor
that is at 20

C (68

F) or below is also okay.

(2) Check the operation sound of the IAC motor can be heard

after the ignition is switched to the "ON" position (but
without starting the engine).

•

An operation sound is heard.

(3) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Did you hear the operation sound?

YES : Go to Step 6.
NO : Refer to, DTC P0506

−

Idle Control System RPM

Lower Than Expected(