Mitsubishi Montero Sport (2004+). Manual — part 288

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-565

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 25 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.13A-4

.

.

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.

• PCM 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

AC306648

RANGE CHECK - MIN/MAX

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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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 PCM.

• 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 determines 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

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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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 E from the evaporative emission canister

side, and plug the hose.

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

• Item 73, Fuel Tank Differential Pressure Sensor.

• The fuel tank pressures reading on the scan tool

should be

−3.3 to 3.3 kPa (−0.97 to 0.97 inHg).

(6) Connect an evaporative emission system pressure pump to

the fuel filler neck and pressurize the fuel tank.

• The fuel tank pressure reading should increase.

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

disconnect scan tool MB991958.

(8) Disconnect the evaporative emission system pressure

pump, and reinstall the fuel cap.

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

−3.3 and 3.3 kPa

(

−0.97 and 0.97 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 Malfunction

P.00-7

). Then go

to Step 16 .

NO : Go to Step 2 .

AK303629AB

MB991911

MB991827

MB991824

16-PIN

AC005140

HOSE E

AC

ACX01358

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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STEP 2. Measure the sensor output voltage at fuel tank
differential pressure sensor connector E- 28.
(1) Disconnect hose E from the evaporative emission canister

side, and plug the hose.

(2) Remove the fuel tank mounting nuts, tilt the fuel tank.

(3) Disconnect fuel tank differential pressure sensor connector

E-28.

(4) Connect special tool MB991658 between pressure sensor

connector terminal 1, 2 and 3.

(5) Turn the ignition switch to the "ON" position.
(6) Remove the fuel cap.
(7) Measure the voltage between terminal 1 and ground.

• The measured voltage should measure between 2.0

and 3.0 volts.

(8) Turn the ignition switch to the "LOCK" (OFF) position.
(9) Disconnect the evaporative emission system pressure

pump, and reinstall the fuel cap.

(10)Connect hose E to the canister.
Q: Is the measured voltage between 2.0 and 3.0 volts?

YES : Go to Step 7 .
NO : Go to Step 3 .

AC005140

HOSE E

AC

AC002614

CONNECTOR: E-28

FUEL TANK
DIFFERENTIAL
PRESSURE
SENSOR

AH

E-28 (B)

2 1

3

E-28 HARNESS SIDE
CONNECTOR

AC002081AB

MB991658

FUEL TANK DIFFERENTIAL
PRESSURE SENSOR