Mitsubishi Galant. Manual — part 300

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-425

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

•

Malfunction of the IAC system.

•

Malfunction of the throttle body.

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 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 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 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

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-426

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.13B-487

).

a. Item 21: Engine Coolant Temperature Sensor.

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

Q: Are they operating properly?

YES : Go to Step 4.
NO : Repair or replace. Then confirm that the malfunction

symptom is eliminated.

STEP 4. Adjust the basic idle speed.
Refer to, Basic Idle Speed Adjustment for the adjustment
procedure (

P.13B-521

).

Standard value: 700

±±±±

50 r/min

Q: Is the idle speed normal?

YES : Refer to, Clean the throttle valve area(

P.13B-520

).

NO : The check is completed.

INSPECTION PROCEDURE 11: When the engine is cold, it stalls at idle (die out).

COMMENT

•

In such cases as the above, the air/fuel mixture
may be inappropriate when the engine is cold.

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

•

Malfunction of the IAC system.

•

Malfunction of the throttle body.

•

Malfunction of the injector system.

•

Malfunction of the ignition 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.

AC003081 AB

16 PIN

MB991502

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-427

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. 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 4.

STEP 4. Check the engine idling.

Q: Is the idling good enough after warm up?

YES : Go to Step 5.
NO : Refer to, INSPECTION PROCEDURE 8

−

Unstable

Idle (Rough Idle, Hunting)(

P.13B-419

).

STEP 5. 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 be 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(

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

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-428

STEP 6. 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 7.
NO : Refer to, DTC P0201,P0203,P0205

−

Injector Circuit

Malfunction(

P.13B-212

),DTC P0202,P0204, P0206

−

Injector Circuit Malfunction(

P.13B-220

)

STEP 7. Using scan tool MB991502, check data list.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following items in the data list. Refer to, Data List

Reference Table(

P.13B-487

).

a. Item 21: Engine Coolant Temperature Sensor.

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

Q: Is the sensor operating properly?

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

symptom is eliminated.

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

P.13B-522

).

Q: Is the fuel pressure normal?

YES : Go to Step 9.
NO : Repair or replace. Then confirm that the malfunction

symptom is eliminated.

AC003081 AB

16 PIN

MB991502

AC003081 AB

16 PIN

MB991502