Mitsubishi Galant 9G. Manual — part 891

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1006

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.13A-33

.

NO : Go to Step 2.

STEP 2. Using scan tool MB991958, check actuator test.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following item in the actuator test. Refer to

Actuator Test Reference Table

P.13A-1097

.

a. Item 08: Evaporative Emission Purge Solenoid.

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

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

defective items.

a. Check the ignition coil and spark plugs.
b. Check for vacuum leaks.

• Broken intake manifold gasket.

• Broken or disconnected vacuum hose.

• Improper operation of the PCV valve.

• Broken air intake hose.

c. Check the EGR valve.

Then confirm that the malfunction symptom is

eliminated.

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

symptom is eliminated.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1007

INSPECTION PROCEDURE 14: The engine stalls when decelerating.

.

COMMENT

• The intake air volume may be insufficient due to a

defective electronic control throttle valve system.

.

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

• Malfunction of the electronic control throttle valve

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.

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.13A-33

.

NO : Go to Step 3.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1008

STEP 3. 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.13A-1083

.

a. Item 79: Throttle Position Sensor (main).
b. Item 14: Throttle Position Sensor (sub).

c. Item 78: Accelerator Pedal Position Sensor (main).

d. Item 77: Accelerator Pedal Position Sensor (sub).

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

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

symptom is eliminated.

STEP 4. Inspection of throttle body (throttle valve area) for
dirtiness.
Q: Is the throttle valve area dirty?

YES : Refer to On-vehicle Service

− Throttle Body (Throttle

Valve Area) Cleaning

P.13A-1124

.

NO : Check the following items, and repair, replace or

clean the defective sections.

a. Check the ignition coil and spark plugs.
b. Check the EGR valve.

Then confirm that the malfunction symptom is

eliminated.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

NEXT>>

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1009

13A

INSPECTION PROCEDURE 15: Hesitation, sag or stumble.

.

COMMENT

• In cases such as the above, the ignition system,

air/fuel mixture or compression pressure may be
defective.

.

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.

• Malfunction of the EGR system.

• Poor compression pressure.

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.13A-33

.

NO : Go to Step 2.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

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