Mitsubishi Galant (2004+). Manual - part 1187

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-441

STEP 9. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− OBD-II Drive Cycle − Procedure 2 − 

Fuel Trim Monitor 

P.13B-5

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0175 output?

YES : Retry the troubleshooting.
NO :  The inspection is complete.

DTC P0181: Fuel Tank Temperature Sensor Circuit Range/Performance

POWERTRAIN CONTROL
MODULE (PCM)

Fuel Tank Temperature  Sensor  Circuit

7

3

1

BLA

CK

D-18

(MU802058)

AK302848

41

FUEL TANK TEMPERATURE SENSOR
(INTEGRATED IN FUEL PUMP MODULE)

C-25

5 V

GRA

Y

-

GREEN

GRA

Y

-

GREEN

B-20

1

2 3

4

5

22

21

23 24 25

26 27 28 29

30 31 32 33 34

35 36 37 38

39 40 41 42 43

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-442

.

CIRCUIT OPERATION

• 5-volt voltage is applied to the fuel tank tempera-

ture sensor output terminal (terminal No. 3) from 
the PCM (terminal No. 41) via the resistor in the 
PCM.

• The fuel tank temperature sensor output voltage 

increases when the resistance increases and 
decreases when the resistance decreases. The 
ground terminal (terminal No. 1) is grounded to 
the vehicle body.

.

TECHNICAL DESCRIPTION

• The fuel tank temperature sensor converts the 

fuel tank temperature to a voltage.

• The PCM detects the fuel tank temperature with 

this output voltage.

.

DESCRIPTIONS OF MONITOR METHODS
Fuel tank temperature at engine start is higher than 

engine coolant temperature at engine start by 
specified value when engine is cold start condi-
tion.

.

MONITOR EXECUTION
Continuous

.

MONITOR EXECUTION CONDITIONS (Other 
monitor and Sensor)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• Not applicable

Sensor (The sensor below is determined to be 

normal)

• Engine coolant temperature sensor

• Intake air temperature sensor

.

AK303085

CONNECTOR: B-20

PCM

AB

AIR CLEANER

B-20

AK303086

CONNECTOR: C-25

C-25

AB

AK303087

SERVICE
HOLE

AB

FUEL PUMP MODULE
(INCORPORATING FUEL LEVEL
SENSOR (MAIN) AND FUEL
TANK TEMPERATURE SENSOR)

CONNECTOR: D-18

D-18 (GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-443

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• The engine coolant temperature − intake air tem-

perature is 5

°C (9°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.

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 (27˚F)

ENGINE COOLANT TEMP.

> =60˚C (140˚F)

ENGINE COOLANT TEMP.

> =60˚C (140˚F)

MAX.VEHICLE SPEED

> 30km/h (17mph)

MAX.VEHICLE SPEED

> 30km/h (17mph)

AK302404

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-444

Judgement Criteria

• The fuel tank temperature − engine coolant tem-

perature is 15

°C (27°F) or more when the engine 

is started.

.

OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function 

− OBD-II Drive Cycle − 

Procedure 6 

− Other Monitor 

P.13B-5

.

.

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 

P.00-6

.

NO :  Go to Step 2.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827