Mitsubishi Galant. Manual — part 270

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-305

STEP 24. Check for clogging in the evaporator line from
hose G and hose H.
(1) Remove the fuel tank. (Refer to GROUP 13C, Fuel

Tank

P.13C-6

.)

(2) Carry out the clogging test with a hand vacuum pump on

each hose from hose G and hose H.

Q: Are there any clogs?

YES : Replace that hose, reinstall the fuel tank. Then go to

Step 26.

NO : Go to Step 25.

STEP 25. Check for clogging in the evaporative emission
canister.
(1) Connect a hand vacuum pump to the vent nipple of the

evaporative emission canister.

(2) Plug the other two nipples or loop a hose between the other

nipples.

(3) Apply vacuum. When each nipple is unplugged, the vacuum

should fluctuate.

Q: Does the vacuum pump gauge reading fluctuate?

YES : Reinstall the fuel tank. Then go to Step 26.
NO : Replace the evaporative emission canister, reinstall

the fuel tank. Then go to Step 26.

STEP 26. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to

P.13B-4

, Procedure 1

−

Evaporative Emission Control

system Leak Monitor.

(2) Read the diagnostic trouble code P0450 does not reset.

Q: Are the DTCs reset?

YES : This diagnosis is complete. (If no malfunctions are not

found in all steps, an intermittent malfunction is
suspected.) Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

−

How to

Cope with Intermittent Malfunction

P.00-8

.

NO : Replace the PCM.

AC002037

HOSE H

AD

HOSE G

AC000191AB

VENT
NIPPLE

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-306

DTC P0451: Fuel Tank Pressure Sensor Range: Min or Max

AC001944

CHECK VALVE A

CHECK
VALVE B

EVAPORATIVE
EMISSION CANISTER

FUEL TANK

EVAPORATIVE
EMISSION
VENTILATION
SOLENOID

EVAPORATIVE EMISSION
PURGE SOLENOID

INTAKE MANIFOLD

SYSTEM DIAGRAM

A

B

C

D

E

F

G

Q

R

I

H

K

J

L

N

O

M

P

AC

FUEL TANK DIFFERENTIAL
PRESSURE SENSOR

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-307

Fuel Tank Differential Pressure Sensor Circuit

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-308

CIRCUIT OPERATION

•

A 5-volt voltage is supplied to the power terminal
of the fuel tank differential pressure sensor
(terminal 3) from the PCM (terminal 46.) The
ground terminal (terminal 2) is grounded with the
PCM (terminal 57.)

•

A voltage proportional to the pressure in the fuel
tank is sent from the output terminal of the fuel
tank differential pressure sensor (terminal 1) to
the PCM (terminal 92.)

TECHNICAL DESCRIPTION

•

To judge if the fuel tank differential pressure
sensor is defective, the PCM monitors the fuel
tank differential pressure sensor output voltage.

•

There are three different sets (A, B, C) of test
conditions and the judgment criteria. Based on
these test conditions and judgment criteria, the
PCM judges if the fuel tank differential pressure
sensor output voltage is normal.

NOTE: In rare cases, this DTC may be also set
under some fuel and driving conditions regardless of
the fuel pressure sensor output voltage when the fuel
system is clogged.

DTC SET CONDITIONS

Test Conditions A: Fuel tank differential pressure

sensor output voltage is less than the upper
limit of the predetermined value

•

Intake air temperature is higher than 5

°

C (41

°

F.)

•

Engine speed is 1,600 r/min or more.

•

Volumetric efficiency is between 25 and 80
percent.

•

Vehicle speed is 30 km/h (18.7 mph) or more.

•

Evaporative emission purge solenoid is driven at
a 100 percent duty when the intake air
temperature is between 5 and 45

°

C (41

−

113

°

F.)

Judgement Criteria A

•

The sensor output voltage remains 4.0 V or more
for 10 seconds or more.

AC005041AB

CONNECTOR:C-17

AC005043

CONNECTORS : C-40, C-41

C-41

C-40

PCM

AB

AC005042 AB

CONNECTOR:C-71

AC002041AC

CONNECTOR: D-11

FUEL TANK DIFFERENTIAL
PRESSURE SENSOR

AC005044 AB

CONNECTOR:D-15