Mitsubishi Eclipse. Manual — part 261

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-537

.

CIRCUIT OPERATION

• A 5-volt voltage is supplied to the power terminal

of the fuel tank differential pressure sensor (ter-
minal 3) from the ECM (terminal 81) <M/T> or
PCM (terminal 46) <A/T>. The ground terminal
(terminal 2) is grounded with the ECM (terminal
92) <M/T> or PCM (terminal 57) <A/T>.

• 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 ECM (terminal 61) <M/T> or PCM (terminal
92) <A/T>.

.

TECHNICAL DESCRIPTION

• To judge if the fuel tank differential pressure sen-

sor is defective, the ECM <M/T> or PCM <A/T>
monitors the fuel tank differential pressure sensor
output voltage.

• Based on the test conditions and judgment crite-

ria, the ECM <M/T> or PCM <A/T> judges if the
fuel tank differential pressure sensor output volt-
age is normal.

.

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

AC001741 AJ

CONNECTOR: C-28

AC001689

CONNECTORS: C-56, C-60<M/T>,
C-54, C-57 <A/T>

ECM <M/T>
OR
PCM <A/T>

AK

C-60
<M/T>

C-56 <M/T>,
C-57<A/T>

C-54
<A/T>

AC001991

CONNECTOR: C-90

CONNECTOR
BLOCK (LH)

AI

AC001787AD

CONNECTOR: D-16

AC103356

FUEL TANK

AD

CONNECTOR: D-18
FUEL TANK DIFFERENTIAL
PRESSURE SENSOR

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-538

Sensor (The sensors below are determined to be

normal)

• Voiume airflow sensor

• Barometric pressure sensor

• Intake air temperature sensor

• Engine coolant temperature sensor

.

LOGIC FLOW CHARTS (Monitor Sequence)

.

DTC SET CONDITIONS

Test Conditions: For Test to Run

• Intake air temperature is higher than 5°C (41°C).

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

• Volumetric efficiency is between 20 and 80 per-

cent.

Judgment Criteria

• When the evaporative emission purge solenoid is

off, the fuel differential pressure sensor output
voltage remains 1.0 volt or less for ten seconds.

.

OBD-ll DRIVE CYCLE PATTERN
Refer to Diagnostic Function

− OBD-ll Drive Cycle −

Procedure 1

− Evaporative Emission System Leak

Monitor

P.12-3

.

.

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

• Fuel tank differential pressure sensor failed.

• Open fuel tank differential pressure sensor cir-

cuit, or loose connector.

• ECM <M/T> or PCM <A/T> failed.

.

NO

YES

CONTINUOUS

FAILURE FOR 10 SECS

START

END

NO

NO

NO

YES

YES

YES

MALFUNCTION

GOOD

MONITORING

CONDITIONS

OUTPUT VOLTAGE

< 1.0V

OUTPUT VOLTAGE

> 4.0V

AC210306

RANGE CHECK - MIN/MAX

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-539

OVERVIEW OF TROUBLESHOOTING

• The DTC P0452 can be set if either of the follow-

ing conditions occur:

1. Faulty fuel differential pressure sensor,

related circuit, or ECM <M/T> or PCM <A/T>.

• To check a system blockage, do a performance

test which uses a mechanical vacuum gauge and
scan tool MB991958 set on the fuel tank differen-
tial pressure sensor (TANK PRS SNSR 73). The
mechanical gauge reading is used to verify scan
tool MB991958 reading. A comparison of the
mechanical gauge to scan tool MB991958 deter-
mines the problem in the system.

.

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B

• MB991658: Test Harness Set

• MB991709: Test Harness Set

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-540

STEP 1. Using scan tool MB991958, check data list item 73:
Fuel Tank Differential Pressure 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) Disconnect hose G from the evaporative emission canister

side, and plug the hose from which the pipes have been
disconnected.

(3) Turn the ignition switch to the "ON" position.
(4) Remove the fuel cap.
(5) Set scan tool MB991958 to the data reading mode for item

73, Fuel Tank Differential Pressure Sensor.

• The fuel tank pressures should be −1.5 to 1.5 kPa

(

−0.443 to 0.443 inHg.)

(6) Connect an evaporative emission system pressure pump to

the fuel filler neck, and apply pressure.

• The scan tool reading should increase.

(7) Turn the ignition switch to the "LOCK" (OFF) position. Then

disconnect scan tool MB991958.

Q: Is the scan tool reading within the specified value?

YES : Go to Step 22.
NO : Go to Step 2.

AC303127

AB

MB991911

16-PIN

MB991827

MB991824

AC002036 AC

HOSE G

AC000186