Mitsubishi Galant 9G. Manual — part 895

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1022

STEP 6. Check the fuel pressure.
Refer to On-vehicle Service

− Fuel Pressure Test

P.13A-1124

.

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 it. Then confirm that the malfunction

symptom is eliminated.

STEP 7. Check the fuel pressure.
Refer to On-vehicle Service

− Fuel Pressure Test

P.13A-1124

.

Q: Is the fuel pressure normal?

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

defective items.

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

Then confirm that the malfunction symptom is

eliminated.

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

symptom is eliminated.

INSPECTION PROCEDURE 20: Knocking

.

COMMENT

• Incase such as the above, the cause is probably

that the detonation control is defective or the heat
value of the spark plug is inappropriate.

.

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

• Defective knock sensor.

• Incorrect heat value of the spark plug.

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1023

STEP 1. Using the 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. Check the ignition timing.
(1) The ignition timing should retard more when knock sensor

connector B-120 is disconnected than when it is connected.

Q: When the knock sensor connector B-120 was

disconnected, was the ignition timing delayed?
YES : Check the following items, and repair or replace the

defective items.

a. Check the spark plugs.
b. Fuel quality, octane level.
c. Check if the foreign materials (water,

kerosene, etc.) got into fuel.

Then confirm that the malfunction symptom is

eliminated.

NO : Refer to DTC P0325

− Knock Sensor Circuit

P.13A-540

.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

AK303856

1

2

AB

CONNECTOR: B-120

KNOCK SENSOR

B-120 (GR)

HARNESS
CONNECTOR:
COMPONENT SIDE

INTAKE
MANIFOLD

INTAKE
MANIFOLD

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1024

INSPECTION PROCEDURE 21: Dieseling (Run-on).

.

COMMENT

• Fuel leakage from injectors is suspected, or car-

bon build up.

.

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

• Fuel leakage from injectors.

DIAGNOSIS

STEP 1. Check the injectors for fuel leakage.
Replace the leaking injector. Then confirm that the malfunction

symptom is eliminated.

INSPECTION PROCEDURE 22: Too high CO and HC concentration when idling

.

COMMENT

• Abnormal air/fuel ratio is suspected.

.

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

• Malfunction of air/fuel ratio control system.

• Deteriorated catalyst.

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

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1025

STEP 2. Check the ignition timing.
Refer to GROUP 11A, On-vehicle Service

− Ignition Timing

Check

P.11A-12

.

Q: Is the ignition timing normal?

YES : Go to Step 3.
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 3. 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 items in the data list. Refer to Data List

Reference Table

P.13A-1083

.

a. Item 21: Engine Coolant Temperature Sensor.
b. Item 13: Intake Air Temperature Sensor.

c. Item 25: Barometric Pressure Sensor.

d. Item 69: Cylinder 1, 4 Heated Oxygen Sensor (rear).
e. Item 39: Cylinder 1, 4 Heated Oxygen Sensor (front).

f. Item 59: Cylinder 2, 3 Heated Oxygen Sensor (rear).

g. Item 11: Cylinder 2, 3 Heated Oxygen Sensor (front).

(4) 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.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827