Mitsubishi Galant. Manual — part 303

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-437

STEP 2. Using scan tool MB991502, check actuator test
items 01, 02, 03, 04, 05, 06: Injector.
(1) Check following items in the actuator test. Refer to, Actuator

Test Reference Table(

P.13B-499

).

a. Item 01, 02, 03, 04, 05, 06: Injector.

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

Q: Is the actuator operating properly?

YES : Go to Step 3.
NO : Refer to, DTC P0201,P0203,P0205

−

Injector Circuit

Malfunction(

P.13B-212

),DTC P0202,P0204,P0206

−

Injector Circuit Malfunction(

P.13B-220

)

STEP 3. Check the ignition timing.
(1) Refer to GROUP 11C, On-vehicle Service

−

Ignition Timing

Check (

P.11C-5

).

Q: Is the ignition timing normal?

YES : Go to Step 4.
NO : Check that the crankshaft position sensor and timing

belt cover are in the correct position. Then confirm
that the malfunction symptom is eliminated.

STEP 4. Using scan tool MB991502, check data list and
actuator test.

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch 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) Check the following items in the data list. Refer to, Data List

Reference Table(

P.13B-487

).

a. Item 13: Intake Air Temperature Sensor.
b. Item 25: Barometric pressure Sensor.

c. Item 21: Engine Coolant Temperature Sensor.

d. Item 14: Throttle Position Sensor.
e. Item 69: Right Bank Heated Oxygen Sensor (rear)

f. Item 39: Right Bank Heated Oxygen Sensor (front)

g. Item 59: Left Bank Heated Oxygen Sensor (rear)
h. Item 11: Left Bank Heated Oxygen Sensor (front)

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

Q: Are they operating properly?

YES : Go to Step 5.
NO : Repair or replace. Then confirm that the malfunction

symptom is eliminated.

AC003081 AB

16 PIN

MB991502

AC003081 AB

16 PIN

MB991502

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-438

STEP 5. Using scan tool MB991502, check actuator test.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following items in the actuator test. Refer to,

Actuator Test Reference Table(

P.13B-499

).

a. Item 10: EGR Solenoid.

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

Q: Is the actuator operating properly?

YES : Go to Step 6.
NO : Repair or replace. Then confirm that the malfunction

symptom is eliminated.

STEP 6. Using scan tool MB991502, check data list.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following items of data list. Refer to, Data List

Reference Table(

P.13B-487

).

a. Item 39: Right Bank Heated Oxygen Sensor (front)
b. Item 11: Left Bank Heated Oxygen Sensor (front)

•

Voltage should fluctuate between 0

−

0.4 volts and 0.6 -

1.0 volts while idling after the engine has warmed-up.

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

Q: Is the sensor operating properly?

YES : Go to Step 8.
NO : Go to Step 7.

STEP 7. Check the fuel pressure.
Refer to, Fuel Pressure Test(

P.13B-522

).

Q: Is the fuel pressure normal?

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

defective items.

a. Vacuum leak.

•

Broken intake manifold gasket.

•

Broken air intake hose.

•

Broken vacuum hose.

•

Positive crankcase ventilation valve does
not operate.

b. Injector clogged.

Then confirm that the malfunction symptom is

eliminated.

NO : Repair or replace. Then confirm that the malfunction

symptom is eliminated.

AC003081 AB

16 PIN

MB991502

AC003081 AB

16 PIN

MB991502

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-439

STEP 8. Check the fuel pressure.
Refer to, Fuel Pressure Test(

P.13B-522

).

Q: Is the fuel pressure normal?

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

defective items.

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

cables.

b. Check the EGR system.

c. Check compression pressure.

d. Check the fuel filter or fuel line for clogging.

Then confirm that the malfunction symptom is

eliminated.

NO : Repair or replace. Then confirm that the malfunction

symptom is eliminated.

INSPECTION PROCEDURE 16: Acceleration shock.

COMMENT

•

There may be an ignition leak accompanying the
increase in the spark plug demand voltage during
acceleration.

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

•

Malfunction of the ignition system.

DIAGNOSIS

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

STEP 1. Using scan tool MB991502, read the diagnostic
trouble code (DTC).

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch 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 : Check the following items, and repair or replace the

defective items.

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

cables.

b. Check for occurrence of ignition leak.

Then confirm that the malfunction symptom is

eliminated.

AC003081 AB

16 PIN

MB991502

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-440

INSPECTION PROCEDURE 17: Deceleration Shock

COMMENT

•

There may be a sudden change in air flow
through the IAC, causing the vehicle to
decelerate rapidly for an instant.

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

•

Malfunction of the IAC system.

DIAGNOSIS

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

STEP 1. Using scan tool MB991502, read the diagnostic
trouble code (DTC).

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch 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 2.

STEP 2. Check the idle air control (IAC) motor operation
sound.
(1) Check that the engine coolant temperature is 20

°

C (68

°

F)

or below.

NOTE: If necessary, you can disconnect the engine coolant
temperature sensor connector and connect the harness
side of the connector to another engine coolant temperature
sensor that is at 20

°

C (68

°

F) or below.

(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 should heard.

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

Q: Did you hear the operation sound?

YES : Go to Step 3.
NO : Refer to, DTC P0506

−

Idle Control System RPM

Lower Than Expected(

P.13B-338

), DTC P0507

−

Idle

Control System RPM Higher Than Expected (

P.13B-

347

).

AC003081 AB

16 PIN

MB991502

ACX02523AG

IDLE AIR
CONTROL
MOTOR