Mitsubishi Galant 9G. Manual — part 1186

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1044

STEP 4. Check the following items.
(1) Carry out the following cleaning.

a. Refer to On-vehicle Service

− Clean the throttle valve

area

P.13B-1178

.

(2) After cleaning, confirm that the malfunction symptom is

eliminated.

Q: Is the malfunction symptom resolved?

YES : The check is completed.
NO : Check the following items, and repair or replace the

defective items.

a. Broken intake manifold gasket.
b. Broken air intake hose.
c. Broken vacuum hose.
d. Positive crankcase ventilation valve does not

operate.

Then confirm that the malfunction symptom is

eliminated.

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-1152

.

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-481

, P0202

P.13B-493

,

P0203

P.13B-504

, DTC P0204

P.13B-516

,

P0205

P.13B-527

, P0206

P.13B-539

− Injector Circuit .

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1045

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-1137

.

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.

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

YES : Go to Step 7.
NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

STEP 7. Using scan tool MB991958, 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-1152

.

a. Item 08: Evaporative Emission Purge Solenoid.

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

YES : Go to Step 8.
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

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1046

STEP 8. Check the fuel pressure.
Refer to On-vehicle Service

− Fuel Pressure Test

P.13B-1179

.

Q: Is the fuel pressure normal?

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

the defective items.

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

− Ignition Timing

Check

P.11C-8

.

Q: Is the ignition timing normal?

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

defective items.

a. Check the ignition coil and spark plugs.
b. Check the purge control system.
c. Check compression pressure.
d. Check if the foreign materials (water,

kerosene, etc.) got into fuel.

e. Check the EGR valve.

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.

NEXT>>

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1047

13B

INSPECTION PROCEDURE 9: Idle speed is high (improper idle speed).

.

COMMENT

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

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

.

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 DTC set?

YES : Refer to Diagnostic Trouble Code Chart

P.13B-34

.

NO : Go to Step 2.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

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