Mitsubishi Eclipse / Eclipse Spyder (2000-2002). Service and repair manual — part 277

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-307

•

The ECM <M/T> or PCM <A/T> must see this
activity during 8 consecutive idling periods from
engine starting.

NOTE: Rapid voltage occurs due to fuel sloshing
during refuelling. However, when the ECM <M/T>
or PCM <A/T> sees the activity mentioned above
8 consecutive times, it judges that an electrical
noise is present.

NOTE: The ECM <M/T> or PCM <A/T>
determines that the engine is not idling if all of the
following conditions are met.

.

•

Engine speed is higher than 2,500 r/min.

•

Vehicle speed is 15 km/h (9.3 mph) or more.

•

Volumetric efficiency is 55 percent or more.

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

•

Fuel tank differential pressure sensor failed.

•

Open or shorted fuel tank differential pressure
sensor circuit, or loose connector.

•

ECM failed <M/T>.

•

PCM failed <A/T>.

•

Blockage of evaporative emission system
(causing high pressure.)

OVERVIEW OF TROUBLESHOOTING

•

The DTC P0450 can be set if either of the
following conditions occur:

1. Faulty fuel differential pressure sensor,

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

2. Faulty fuel filler neck evaporative emission

ventilation solenoid or blocked vapor line.

•

To check a system blockage, do a performance
test which uses a mechanical vacuum gauge and
the scan tool MB991502 set on the fuel tank
differential pressure sensor (TANK PRS
SNSR73.)
The mechanical gauge reading is used to verify
the scan tool MB991502 reading.
A comparison of the mechanical gauge to the
scan tool MB991502 determines the problem in
the system.

DIAGNOSIS

Required Special Tools:

•

MB991502: Scan Tool (MUT-II)

•

MB991658: Test Harness Set

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-308

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to "LOCK" (OFF) position before
connecting or disconnecting scan tool MB991502.

STEP 1. Using scan tool MB991502, check data list item 73:
Fuel Tank Differential Pressure Sensor.
(1) Connect scan tool MB991502 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Remove the fuel cap.
(4) Set scan tool MB991502 to the data reading mode for item

73, Fuel Tank Differential Pressure Sensor.

•

The fuel tank pressures should be

−

1.5 to 1.5kPa.

(5) Connect an evaporative emission system pressure pump to

the fuel filler neck, and apply pressure.

•

The scan tool reading should increase.

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

YES : Go to Step 20.
NO : Go to Step 2.

STEP 2. Check the output circuit voltage at intermediate
connector D-16.
(1) Remove the rear seat cushion. (Refer to GROUP 52A, Rear

Seat

P.52A-23

.)

(2) Remove the protector.
(3) Do not disconnect intermediate connector D-16.
(4) Use special tools (MB991658 and MB991709) to connect

terminals 5, 6 and 8 between connectors of the
intermediate connector, respectively.

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

backprobing.

•

Voltage should be between 2.0 and 3.0 volts.

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

Q: Is the multi-meter reading within the specified value?

YES : Go to Step 10.
NO : Go to Step 3.

AC001252

MB991502

16 PIN

AB

AC000186

AC002079 AB

MB991709

MB991658

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-309

STEP 3. Check the 5-volt supply circuit voltage at
intermediate connector D-16.
(1) Do not disconnect intermediate connector D-16.
(2) Use special tools (MB991658 and MB991709) to connect

terminals 5, 6 and 8 between connectors of the
intermediate connector, respectively.

(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between terminal 8 and ground by

backprobing.

•

Voltage should be between 4.8 and 5.2 volts.

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

Q: Is the multi-meter reading within the specified value?

YES : Go to Step 4.
NO : Go to Step 11.

STEP 4. Check the ground circuit voltage at intermediate
connector D-16.
(1) Do not disconnect intermediate connector D-16.
(2) Use special tools (MB991658 and MB991709) to connect

terminals 5, 6 and 8 between connectors of the
intermediate connector, respectively.

(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between terminal 6 and ground by

backprobing.

•

Voltage should be between 0.5 volts or less.

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

Q: Is the multi-meter reading within the specified value?

YES : Go to Step 5.
NO : Go to Step 15.

STEP 5. Check the output circuit voltage at fuel tank
differential pressure connector D-18.
(1) Remove the center pipe.
(2) Remove the fuel band assembly, tilt the fuel tank.
(3) Disconnect fuel tank differential pressure sensor connector

D-18.

(4) Use special tool (MB991658) to connect terminals 1, 2 and

3 of the disconnected sensor connector and those of the
harness side connector, respectively.

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

backprobing.

•

Voltage should be between 2.0 and 3.0 volts.

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

Q: Is the multi-meter reading within the specified value?

YES : Go to Step 17.
NO : Go to Step 6.

AC002080

MB991709

MB991658

AB

AC002079 AB

MB991709

MB991658

AC002081AB

MB991658

FUEL TANK DIFFERENTIAL
PRESSURE SENSOR

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-310

STEP 6. Check the 5-volt supply circuit voltage at fuel tank
differential pressure sensor connector D-18.
(1) Do not disconnect fuel tank differential pressure sensor

connector D-18.

(2) Use special tool (MB991658) to connect terminals 1, 2 and

3 of the disconnected sensor connector and those of the
harness side connector, respectively.

(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between terminal 3 and ground by

backprobing.

•

Voltage should be between 4.8 and 5.2 volts.

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

Q: Is the multi-meter reading within the specified value?

YES : Go to Step 7.
NO : Go to Step 17.

STEP 7. Check the ground circuit voltage at fuel tank
differential pressure sensor connector D-18.
(1) Disconnect fuel tank differential pressure sensor connector

D-18.

(2) Use special tool (MB991658) to connect terminals 1, 2 and

3 of the disconnected sensor connector and those of the
harness side connector, respectively.

(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between terminal 2 and ground by

backprobing.

•

Voltage should be between 0.5 volts or less.

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

Q: Is the multi-meter reading within the specified value?

YES : Go to Step 8.
NO : Go to Step 17.

STEP 8. Check fuel tank differential pressure sensor
connector D-18 for damage.
(1) Disconnect fuel tank differential pressure sensor connector

D-18.

Q: Is there any failure at fuel tank differential pressure

sensor connector D-18?
YES : Go to Step 9.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 26.

AC002081AB

MB991658

FUEL TANK DIFFERENTIAL
PRESSURE SENSOR

AC002081AB

MB991658

FUEL TANK DIFFERENTIAL
PRESSURE SENSOR

AC002041AB

CONNECTOR: D-18

FUEL TANK DIFFERENTIAL
PRESSURE SENSOR