Mitsubishi Galant 9G. Manual - part 812

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-690

(9) Connect hose I to the evaporative emission canister.
Q: Is the fuel tank pressure between 

−1.5 and 1.5 kPa 

(

−0.443 and 0.443 inHg)?

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

). Go to 

Step 17.

NO :  Replace the PCM (Refer to 

P.13A-1140

). Then go to 

Step 17     .

STEP 17. Perform the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern (Refer to 

Diagnostic Function 

− OBD-ll Drive Cycle − Procedure 1 − 

Evaporative Emission System Leak Monitor 

P.13A-6

).

(2) Read the diagnostic trouble code (DTC).
Q: Is DTC P0451 set?

YES : Repeat the troubleshooting from Step 2.
NO :  The procedure is complete.

DTC P0452: Evaporative Emission System Pressure Sensor Low Input

AC306277

A

B

C

D

E

F

G

H

P

Q

R

O

N

M

I

J

K

L

AC

INTAKE MANIFOLD

FUEL TANK

EVAPORATIVE EMISSION
VENTILATION SOLENOID

CHECK VALVE

EVAPORATIVE EMISSION
PURGE SOLENOID

EVAPORATIVE 
EMISSION CANISTER

ONBOARD REFUELING
VAPOR RECOVERY(ORVR)
VENT VALVE MODULE

FUEL TANK DIFFERENTIAL 
PRESSURE SENSOR

SYSTEM DIAGRAM

CHAMBER

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-691

FUEL TANK 
DIFFERENTIAL 
PRESSURE 
SENSOR

POWERTRAIN 
CONTROL 
MODULE

Fuel Tank Differential Pressure Sensor Circuit

AC306128

AC306248

B-20 HARNESS

CONNECTOR:

COMPONENT SIDE

AB

B-20

CONNECTOR: B-20

PCM

AIR
CLEANER

AC305231

CONNECTOR: C-25

AM

C-25

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-692

.

CIRCUIT OPERATION

• The PCM (terminal 21) supplies a 5-volt refer-

ence signal to the fuel tank differential pressure 
sensor (terminal 3). The fuel tank differential 
pressure sensor (terminal 2) is grounded through 
the PCM (terminal 22).

• The fuel tank differential pressure sensor (termi-

nal 1) returns a voltage signal to the PCM (termi-
nal 23) that is proportional to the pressure in the 
fuel tank.

.

TECHNICAL DESCRIPTION

• The PCM monitors the fuel tank differential pres-

sure sensor output voltage.

• The PCM determines whether the fuel tank differ-

ential pressure sensor signal voltage is within 
normal operating parameters.

.

DESCRIPTIONS OF MONITOR METHODS

• Compare purge solenoid status with fuel tank dif-

ferential pressure sensor output voltage.

.

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)

• Evaporative emission purge solenoid monitor

• Evaporative emission ventilation solenoid monitor

 Sensor (The sensors below are determined to be 

normal)

• Mass airflow sensor

• Barometric pressure sensor

• Intake air temperature sensor

• Engine coolant temperature sensor

• Accelerator pedal position sensor

.

AC305266

CONNECTOR: D-23

AB

D-23 (B)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-693

LOGIC FLOW CHARTS (Monitor Sequence)

.

DTC SET CONDITIONS

Check Conditions

• 2 seconds or more have passed since the start-

ing sequence was completed.

Judgment Criteria

• The fuel tank differential pressure sensor output 

voltage remains 0.2 volt or less for 5 seconds.

.

OBD-ll DRIVE CYCLE PATTERN

Refer to Diagnostic Function 

− OBD-ll Drive Cycle − 

Procedure 1 

− Evaporative Emission System Leak 

Monitor 

P.13A-6

.

.

TROUBLESHOOTING HINTS (THE MOST 
LIKELY CAUSES FOR THIS CODE TO BE 
SET ARE:)

• Malfunction of the fuel tank differential pressure 

sensor.

• A damaged harness in the fuel tank differential 

pressure sensor circuit.

• Malfunction of the PCM.

.

AC401447

RANGE CHECK - MIN. / MAX.

NO

YES 

CONTINUOUS

FAILURE FOR 5 SECS

START 

END 

NO 

NO

NO

YES 

YES 

 

YES 

MALFUNCTION

 

GOOD 

MONITORING

 

CONDITIONS

 

OUTPUT VOLTAGE

 

< 1.0V

OUTPUT VOLTAGE

 

> 4.8V