Mitsubishi Outlander GS45X. Manual — part 894

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-509

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• Accelerator pedal is not depressed.

• Vehicle speed is less than 1.5 km/h (1 mph).

NOTE: The conditions for deviating from idling
operation are as follows:

.

•

Vehicle speed is more than 50 km/h (31 mph).

Judgement Criteria

• The drastic pressure fluctuation is detected 20

times or more per engine idling, which is that the
fuel tank differential pressure sensor output volt-
age is 0.2 volt or more.

AK705072

Start

Off-idling condition

Idling condition?

F1 = 0

Off-idling condition

Yes

No

End

No

Malfunction

F1 > 20

FTPS output voltage

fluctuation > 0.2V

No

Yes

Yes

F1 = F1 + 1

Good

No

Yes

Yes

No

Yes

No

Specified times

monitored

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-510

• The condition described above is consecutively

detected 4 times under the normal driving condi-
tions.
NOTE: If the number of sudden pressure fluctua-
tions does not reach 20 times during any one
period of engine idling, or if the ignition switch is
turned OFF, the counter will reset to 0.

.

OBD-ll DRIVE CYCLE PATTERN

Refer to Diagnostic Function

− OBD-ll Drive Cycle −

Pattern 16

P.13B-11

.

.

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

• Connector damage.

• Harness damage.

• Fuel tank differential pressure sensor failed.

• ECM failed.

.

OVERVIEW OF TROUBLESHOOTING

• DTC P0451 can be set by a faulty fuel tank differ-

ential pressure sensor or related circuit, or ECM
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 (52: Fuel tank differential
PRS. SNSR). The mechanical gauge reading is
used to verify scan tool MB991958 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 (M.U.T.-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: M.U.T.-III USB Cable

• MB991910: M.U.T.-III Main Harness A

• MB992110: Power Plant ECU Check Harness

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

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STEP 1. Using scan tool MB991958, check data list item 52:
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 C 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 52, Fuel Tank Differential Pressure Sensor.

• The fuel tank pressure reading on the scan tool

should be 1,500 to 3,500 mV.

(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 C to the evaporative emission canister.
Q: Is the fuel tank pressure between 1,500 and 3,500 mV?

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.00-15

).

NO : Go to Step 2 .

AK700568AB

MB991824

MB991827

MB991910

Data link
connector

AK704159

Hose C

Plug

AB

AK704160

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-512

STEP 2. Check harness connector B-11 at ECM and
harness connector D-19 at fuel tank differential pressure
sensor for damage.
Q: Is the harness connector in good condition?

YES : Then go to Step 3 .
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 7 .

STEP 3. Measure the 5-volt reference signal at fuel tank
differential pressure sensor connector D-19.
(1) Remove the second seat assembly (Refer to GROUP 52A,

Second Seat Assembly

P.52A-25

).

(2) Remove the floor inspection lid (LH).
(3) Disconnect fuel tank differential pressure sensor connector

D-19.

(4) Turn the ignition switch to the "ON" position.

(5) Measure the voltage between terminal 3 and ground.

• The voltage should measure between 4.9 and 5.1 volts.

(6) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.9 and 5.1 volts?

YES : Go to Step 5 .
NO : Go to Step 4 .

AK704172

Floor inspection lid (LH)

AB

AK704173

1

2

3

AB

D-19 Harness
connector:
component side