Mitsubishi Galant. Manual — part 301

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-429

STEP 9. Check the ignition timing.
Refer to GROUP 11C, On-vehicle Service

−

Ignition Timing

Check (

P.11C-5

).

Q: Is the ignition timing 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 engine oil viscosity.

Then confirm that the malfunction symptom is

eliminated.

NO : Check that the crankshaft position sensor and timing

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

INSPECTION PROCEDURE 12: When the Engine Is Hot, It Stalls at Idle (Die Out).

COMMENT

•

In cases such as the above, the ignition system,
air/fuel mixture, idle air control motor or
compression pressure may be faulty. In addition,
if the engine suddenly stalls, the cause may also
be a loose connector.

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.

•

Vacuum leak.

•

Improper connector contact.

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.

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.0L>

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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 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 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 that 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 be heard.

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

Q: Did you hear the operation sound?

YES : Go to Step 4.
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

).

STEP 4. Using scan tool MB991502, check actuator test
items 01, 02, 03, 04, 05, 06: Injector.

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 following items in the actuator test. Refer to, Actuator

Test Reference Table(

P.13B-499

).

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

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

Q: Is the actuator operating properly?

YES : Go to Step 5.
NO : Refer to, DTC P0201,P0203,P0205

−

Injector Circuit

Malfunction(

P.13B-212

),DTC P0202,P0204,P0206

−

Injector Circuit Malfunction(

P.13B-220

)

AC003081 AB

16 PIN

MB991502

ACX02523AG

IDLE AIR
CONTROL
MOTOR

AC003081 AB

16 PIN

MB991502

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.0L>

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STEP 5. Checking by operating the accelerator pedal

Q: Does the engine stall right after the accelerator pedal is

released?
YES : Refer to, Clean the throttle valve area(

P.13B-520

).

NO : Go to Step 6.

STEP 6. Engine stall reproduction test.

Q: Is it easy to reproduce the engine stall?

YES : Go to Step 7.
NO : Check if the following signals change suddenly by

wiggling the circuit harness and connectors.

a. Crankshaft position sensor signal.
b. Volume air flow sensor signal.

c. Injector drive signal.

d. Primary and secondary ignition signal.
e. Fuel pump drive signal.

f. PCM power supply voltage.

Repair or replace. Then confirm that the malfunction

symptom is eliminated.

STEP 7. 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.13B-487

).

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

c. Item 21: Engine Coolant Temperature Sensor.

d. Item 69: Right Bank Heated Oxygen Sensor (rear)
e. Item 39: Right Bank Heated Oxygen Sensor (front)

f. Item 59: Left Bank Heated Oxygen Sensor (rear)

g. Item 11: Left Bank Heated Oxygen Sensor (front)
h. Item 27: Power Steering Pressure Switch.

i. Item 28: A/C Switch.

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

Q: Are they operating properly?

YES : Go to Step 8.
NO : Repair or replace. Then confirm that the malfunction

symptom is eliminated.

AC003081 AB

16 PIN

MB991502

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.0L>

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STEP 8. 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 9.
NO : Repair or replace. Then confirm that the malfunction

symptom is eliminated.

STEP 9. Using scan tool MB991502, check data list.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following items of the 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)

•

Fluctuates 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 12.
NO : Go to Step 10.

STEP 10. Check the fuel pressure.
Refer to, Fuel Pressure Test(

P.13B-522

).

Q: Is the fuel pressure normal?

YES : Go to Step 11.
NO : Repair or replace. Then confirm that the malfunction

symptom is eliminated.

AC003081 AB

16 PIN

MB991502

AC003081 AB

16 PIN

MB991502