Mitsubishi Galant 9G. Manual - part 756

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-466

DTC SET CONDITIONS <Circuit continuity 

− open circuit and shorted low>

Logic Flow Chart

Check Conditions

• Engine is running.

Judgment Criteria

• The supply voltage is 3 volts or less without the 

injector driving.

.

START

END

NO

NO

NO

YES

YES

YES

MALFUNCTION

GOOD

MONITORING

CONDITIONS

CONTINUOUS

FAILURE FOR 2secs

INJ. SURGE V

<= 3 V

AK401614

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-467

DTC SET CONDITIONS <Circuit continuity 

− open circuit and shorted high>

Logic Flow Chart

Check Conditions

• Engine is running.

Judgement Criteria

• The coil current is 4 ampere or more with the 

injector driving.

.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function 

− OBD-II Drive Cycle − 

Procedure 6 

− Other Monitor 

P.13A-6

.

.

TROUBLESHOOTING HINTS (The most 
likely causes for this code to be set are:)

• No.1 cylinder injector failed.

• Open or shorted No.1 cylinder injector circuit, 

harness damage or connector damage.

• PCM failed.

START

END

NO

NO

NO

YES

YES

YES

MALFUNCTION

GOOD

MONITORING

CONDITIONS

CONTINUOUS

FAILURE FOR 2secs

CURRENT

>= 4 A

AK401592

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-468

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

• MB991658: Test Harness

• MB991923: Power Plant ECU Check Harness

STEP 1. Using scan tool MB991958, check actuator test 
item 01: No. 1 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) Start the engine and run at idle.
(3) Set scan tool MB991958 to the actuator testing mode for 

item 01 No. 1 injector.

(4) Warm up the engine to normal operating temperature: 80

°C 

to 95

°C (176°F to 203°F).

• The idle should become slightly rougher.

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

YES : It can be assumed that this malfunction is intermittent. 

Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

− How to 

Cope with Intermittent Malfunctions 

P.00-14

.

NO :  Go to Step 2.

STEP 2. Check harness connector B-01 at No. 1 cylinder 
injector for damage.
Q: Is the harness connector in good condition?

YES : Go to Step 3.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 10.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

M

1

2

AK303843

B-01 (GR)

CONNECTOR: B-01

AB

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-469

STEP 3. Check the No. 1 cylinder injector.
(1) Disconnect the No. 1 cylinder injector connector B-01.

(2) Measure the resistance between injector side connector 

terminal No. 1 and No. 2.

Standard value: 10.5 

− 13.5 ohms [at 20°C (68°F)]

Q: Is the measured resistance between 10.5 and 13.5 ohms 

[at 20

°C (68°F)]?

YES : Go to Step 4.
NO :  Replace the No. 1 cylinder injector. Then go to Step 

10.

STEP 4. Measure the power supply voltage at No. 1 
cylinder injector connector.
(1) Disconnect connector B-01 and measure at the harness 

side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 1 and ground.

• Voltage should be battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is battery positive voltage (approximately 12 volts) 

present?
YES : Go to Step 6.
NO :  Go to Step 5.

M

1

2

AK303843

B-01 (GR)

CONNECTOR: B-01

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AK000559

2

1

INJECTOR SIDE
CONNECTOR

AB

M

1

2

AK303843

B-01 (GR)

CONNECTOR: B-01

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AK000560

1

2

B-01 HARNESS
CONNECTOR:
COMPONENT SIDE

AN