Mitsubishi Galant 9G. Manual — part 818

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-714

LOGIC FLOW CHARTS (Monitor Sequence)

.

DTC SET CONDITIONS

Check Conditions

• 2 seconds or more have passed since the start-

ing sequence was completed.

• The fuel temperature is 36°C (97°F) or less.

• Remaining fuel level is 85% or less when the

engine is started.

Judgment Criteria

• The fuel tank differential pressure sensor output

voltage remains 4.8 volt or greater 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.

• Open or shorted 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

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

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OVERVIEW OF TROUBLESHOOTING

• DTC P0453 can be set by a faulty fuel tank differ-

ential pressure sensor or related circuit, or PCM
failure.

• To check for 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 reading. A comparison of the mechanical
gauge with the reading on scan tool MB991958
will locate a problem in the system.

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A

• MB991658: Test Harness Set

• MB991923: Power Plant ECU Check Harness

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

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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 I from the evaporative emission canister,

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 pressure reading on the scan tool

should be

−1.5 to 1.5 kPa (−0.443 to 0.443 inHg).

(6) Connect the evaporative emission system pressure pump

(Miller number 6872A) to the fuel tank filler tube by using
fuel tank adapter (MLR-8382) 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) Remove the evaporative emission system pressure pump

(Miller number 6872A) and the fuel tank adapter
(MLR-8382), and reinstall the fuel cap.

(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 : Go to Step 2.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC306778

AB

HOSE I

PLUG

AC306661

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-717

STEP 2. Measure the sensor output voltage at PCM
connector B-20 by using check harness special tool
MB991923.
(1) Disconnect all the connectors from the PCM.

(2) Connect special tool MB991923 (check harness) between

the PCM and the body-side harness connector.

(3) Turn the ignition switch to the "ON" position.
(4) Remove the fuel cap.

AC306248

B-20 HARNESS

CONNECTOR:

COMPONENT SIDE

AB

B-20

CONNECTOR: B-20

PCM

AIR
CLEANER

AC209793AJ

SPECIAL TOOL 23-PIN CONNECTOR
WITHOUT RED TAPE
(PCM CONNECTOR B-20)

B-20

PCM

MB991923

BODY SIDE
HARNESS