Mitsubishi Galant 9G. Manual - part 749

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-438

DTC SET CONDITIONS
Logic Flow Chart

.

Check Conditions

• The engine coolant temperature − intake air tem-

perature is 5

°C (41°F) or less when the engine is 

started.

• The engine coolant temperature is between 

−10°C (14°F) and 36°C (97°F) when the engine is 

started.

• The engine coolant temperature is higher than 

60

°C (140°F).

• Maximum vehicle speed is higher than 30 km/h 

(19 mph) after the engine starting sequence has 
been completed.

Judgement Criteria

• The fuel tank temperature − engine coolant tem-

perature is 15

°C (59°F) or more when the engine 

is started.

START

NO

YES

YES

YES

YES

NO

NO

NO

END

NO

YES

YES

NO

MALFUNCTION

GOOD

MONITORING

CONDITIONS

“FUEL TEMP. AT 

ENGINE START” -

“ENGINE COOLANT TEMP. AT 

ENGINE START”

> 15˚C (59˚F)

ENGINE

COOLANT TEMP.

> =60˚C (140˚F)

ENGINE

COOLANT TEMP.

> =60˚C (140˚F)

MAX.

VEHICLE SPEED

> 30km/h (19mph)

MAX.

VEHICLE SPEED

> 30km/h (19mph)

AK401537

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-439

.

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:)

• Fuel tank temperature sensor failed.

• Open or shorted fuel tank temperature sensor cir-

cuit, harness damage, or connector damage.

• PCM failed. 

NOTE: A diagnostic trouble code (DTC) could be 
output if the engine and the radiator have been 
flushed repeatedly when the engine coolant temper-
ature was high (or the fuel tank temperature was 
high). Because this is not a failure, the DTC must be 
erased.
Make sure to test drive the vehicle in accordance 
with the OBD-II drive cycle pattern in order to verify 
that a DTC will not be output.

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

• MB991923: Power Plant ECU Check Harness

STEP 1. Using scan tool MB991958, check data list item 
4A: Fuel Tank Temperature Sensor.

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) Set scan tool MB991958 to the data reading mode for item 

4A, Fuel Tank Temperature Sensor.

• Approximately the same as the ambient air temperature 

when the engine is cooled.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor 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.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-440

STEP 2. Check harness connector D-18 at the fuel tank 
temperature sensor 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 12.

STEP 3. Check the fuel tank temperature sensor.
(1) Disconnect the fuel tank temperature sensor connector 

D-18.

(2) Measure the resistance between terminal No. 1 and No. 3 

of the fuel tank temperature sensor.

Standard value:

0.5 

− 12.0 kΩ

Q: Is the measured resistance between 0.5 and 12.0 k

Ω?

YES : Go to Step 4.
NO :  Replace the fuel tank temperature sensor. Then go to 

Step 12.

AK303840

1

2

3

4

5

SERVICE
HOLE

AB

CONNECTOR: D-18

D-18 (GR)

HARNESS 
CONNECTOR: 
COMPONENT SIDE

AK303840

1

2

3

4

5

SERVICE
HOLE

AB

CONNECTOR: D-18

D-18 (GR)

HARNESS 
CONNECTOR: 
COMPONENT SIDE

1

2 3

4

5

AK203165

FUEL TANK TEMPERATURE
SENSOR CONNECTOR

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-441

STEP 4. Check the continuity at fuel tank temperature 
sensor harness side connector D-18.
(1) Disconnect the connector D-18 and measure at the harness 

side.

(2) Check for the continuity between terminal No. 1 and 

ground.

• Should be less than 2 ohms.

Q: Does continuity exist?

YES : Go to Step 5.
NO :  Repair harness wire between fuel tank temperature 

sensor connector D-18 (terminal No. 1) and ground 
because of open circuit or harness damage. Then go 
to Step 12.

STEP 5. Measure the sensor supply voltage at fuel tank 
temperature sensor harness side connector D-18.
(1) Disconnect the connector D-18 and measure at the harness 

side.

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

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

• Voltage should be between 4.5 and 4.9 volts

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.5 and 4.9 volts?

YES : Go to Step 6.
NO :  Go to Step 10.

AK303840

1

2

3

4

5

SERVICE
HOLE

AB

CONNECTOR: D-18

D-18 (GR)

HARNESS 
CONNECTOR: 
COMPONENT SIDE

1

2

3

4

5

AK203166

D-18 HARNESS 
CONNECTOR: 
COMPONENT SIDE

AC

AK303840

1

2

3

4

5

SERVICE
HOLE

AB

CONNECTOR: D-18

D-18 (GR)

HARNESS 
CONNECTOR: 
COMPONENT SIDE

1

2

3

4

5

AK203167

D-18 HARNESS 
CONNECTOR: 
COMPONENT SIDE

AC