Mitsubishi Galant (2004+). Manual — part 1327

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1001

INSPECTION PROCEDURE 10: Idle Speed Is Low (Improper Idle Speed).

.

COMMENT

• In cases such as the above, the cause is proba-

bly that the intake air volume during idle is too
small.

.

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

• Malfunction of the electronic control throttle valve

system.

• Malfunction of the throttle body.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

STEP 1. Using scan tool MB991958, read the diagnostic
trouble code (DTC).

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 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 set?

YES : Refer to Diagnostic Trouble Code Chart

P.13B-33

.

NO : Go to Step 2.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1002

STEP 2. Using scan tool MB991958, check data list.

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check the following item in the data list. Refer to Data List

Reference Table

P.13B-1092

.

a. Item 21: Engine Coolant Temperature Sensor.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : Refer to On-vehicle Service

− Clean the throttle valve

area

P.13B-1133

.

NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

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 electronic control throttle valve

system.

• Malfunction of the throttle body.

• Malfunction of the injector system.

• Malfunction of the ignition system.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

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.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1003

STEP 2. Using scan tool MB991958, read the diagnostic
trouble code (DTC).

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 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 set?

YES : Refer to Diagnostic Trouble Code Chart

P.13B-33

.

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 GROUP13A, On-vehicle Service

− Throttle

Body (Throttle Valve Area) Cleaning.

P.13B-1133

.

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-995

.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1004

STEP 5. Using scan tool MB991958, check actuator test
items 01, 02, 03, 04, 05, 06: Injector.

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 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-1106

.

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

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Are they operating properly?

YES : Go to Step 6.
NO : Refer to DTC P0201

P.13B-471

, P0202

P.13B-482

,

P0203

P.13B-492

, DTC P0204

P.13B-503

,

P0205

P.13B-513

, P0206

P.13B-524

− Injector Circuit.

STEP 6. Using scan tool MB991958, 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-1092

.

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 7.
NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827