Mitsubishi Galant. Manual — part 169

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-357

STEP 3. Using scan tool MB991502, check data list.

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.13A-405

).

a. Item 14: Throttle Position Sensor.

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

Q: Is the sensor operating properly?

YES : Refer to, Clean the throttle valve area(

P.13A-436

).

NO : Repair or replace. Then confirm that the malfunction

symptom is eliminated.

INSPECTION PROCEDURE 18: Poor acceleration.

COMMENT

•

Defective ignition system, abnormal air/fuel ratio,
poor compression pressure, etc. are suspected.

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

•

Malfunction of the ignition system.

•

Malfunction of air/fuel ratio control system.

•

Malfunction of the fuel supply system.

•

Poor compression pressure.

•

Clogged exhaust 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.13A-20

).

NO : Go to Step 2.

AC003081 AB

16 PIN

MB991502

AC003081 AB

16 PIN

MB991502

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-358

STEP 2. Using scan tool MB991502, check actuator test
items 01, 02, 03, 04: Injector.
(1) Turn the ignition switch to the "ON" position.
(2) Check following items in the actuator test. Refer to, Actuator

Test Reference Table(

P.13A-416

).

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

(3) 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, P0202, P0203, P0204

−

Injector Circuit Malfunction(

P.13A-154

).

STEP 3. Check the ignition timing.
Refer to GROUP 11A, On-vehicle Service

−

Ignition Timing

Check (

P.11A-6

).

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.

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.13A-405

).

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 59: Heated Oxygen Sensor (rear)

f. Item 11: 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) <2.4L>

13A-359

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.13A-416

).

a. Item 10: EGR Solenoid.

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

Q: Are they 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.13A-405

).

a. Item 11: Heated Oxygen Sensor (front)

•

Voltage should fluctuate between 0

−

0.4 volts and 0.6 -

1.0 volts while idling after the engine has been warmed.

(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.13A-439

).

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) <2.4L>

13A-360

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

P.13A-439

).

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 compression pressure.

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

d. Broken air intake hose.
e. Clogged air cleaner.

f. Clogged exhaust system.

Then confirm that the malfunction symptom is

eliminated.

NO : Repair or replace. Then confirm that the malfunction

symptom is eliminated.

INSPECTION PROCEDURE 19: Surge.

COMMENT

•

Defective ignition system, abnormal air/fuel ratio,
etc. are suspected.

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

•

Malfunction of the ignition system.

•

Malfunction of air/fuel ratio control system.

•

Malfunction of the EGR solenoid 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 "ON" position.

Q: Is the DTC is output?

YES : Refer to, Diagnostic Trouble Code Chart(

P.13A-20

).

NO : Go to Step 2.

AC003081 AB

16 PIN

MB991502