Mitsubishi Galant (2004+). Manual — part 1037

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-965

STEP 8. Check harness connector B-23 at PCM for
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 9.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then confirm that the

malfunction symptom is eliminated.

127 126 125 124 123 122 121

133 132 131 130 129 128

140 139 138 137 136 135 134

146 145 144 143 142 141

153 152 151 150 149 148 147

AK303058

HARNESS CONNECTOR:
COMPONENT SIDE

CONNECTOR: B-23

B-23

PCM

AIR CLEANER

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

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STEP 9. Check for harness damage between injector
connector and PCM connector.

a. Check the harness wire between injector connector B-01

(terminal No. 2) and PCM connector B-23 (terminal No.
153) at No. 1 cylinder.

b. Check the harness wire between injector connector B-30

(terminal No. 2) and PCM connector B-23 (terminal No.
146) at No. 2 cylinder.

c. Check the harness wire between injector connector B-03

(terminal No. 2) and PCM connector B-23 (terminal No.
140) at No. 3 cylinder.

d. Check the harness wire between injector connector B-27

(terminal No. 2) and PCM connector B-23 (terminal No.
139) at No. 4 cylinder.

Q: Is the harness wire in good condition?

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

defective items.

a. Check the ignition coil and spark plugs.
b. Check if the injectors are clogged.

c. Check compression pressure.

d. Check if the foreign materials (water,

kerosene, etc.) got into fuel.

Then confirm that the malfunction symptom is

eliminated.

NO : Repair it. Then confirm that the malfunction symptom

is eliminated.

AK303920

B-01 (GR)

B-03 (GR)

B-30 (GR)

B-27 (GR)

CONNECTORS: B-01, B-03, B-27, B-30

HARNESS CONNECTOR:
COMPONENT SIDE

127 126 125 124 123 122 121

133 132 131 130 129 128

140 139 138 137 136 135 134

146 145 144 143 142 141

153 152 151 150 149 148 147

AK303058

HARNESS CONNECTOR:
COMPONENT SIDE

CONNECTOR: B-23

B-23

PCM

AIR CLEANER

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-967

INSPECTION PROCEDURE 8: Unstable Idle (Rough Idle, Hunting).

COMMENT

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

bly the air/fuel mixture or electronic control throt-
tle valve system. Other systems affecting idle
quality include the ignition system and compres-
sion.

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

• Malfunction of the ignition system.

• Malfunction of air/fuel ratio control system.

• Malfunction of the electronic control throttle valve

system.

• Malfunction of the evaporative emission purge

solenoid system.

• Malfunction of the EGR valve.

• Poor compression pressure.

• Vacuum leak.

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 is 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-34

NO : Go to Step 3.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

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STEP 3. Check the engine idling state.
Q: Is it noticeably hunting?

YES : Go to Step 4.
NO : Go to Step 5.

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

a. Refer to On-vehicle Service

− Clean the throttle valve

area

P.13A-1104

(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: 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.13A-1076

a. Item 01, 02, 03, 04: 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

− Injector Circuit-cylinder 1

P.13A-461

, DTC P0202

− Injector Circuit-cylinder 2

P.13A-470

, DTC P0203

− Injector Circuit-cylinder 3