Mitsubishi Eclipse. Manual - part 543

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-715

OVERVIEW OF TROUBLESHOOTING

• The DTC P0453 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) <3.0L>

13B-716

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 

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 

AC002072 AB

HOSE I

AC000186

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-717

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-19

.)

(2) Remove the protector.
(3) 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.

• Voltage should be between 2.0 and 3.0 volts.

(8) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?

YES : Remove the special tools and connect intermediate 

connector D-16. Then go to Step 3 .

NO :  Go to Step 6.

STEP 3. Check the output circuit voltage at ECM connector 
C-62 <M/T> or PCM connector C-59 <A/T> by backprobing. 
(1) Do not disconnect the ECM connector C-62 <M/T> or PCM 

connector C-59 <A/T>.

(2) Turn the ignition switch to the "ON" position.
(3) Remove the fuel cap.
(4) Measure the voltage between terminal 93 <M/T> or terminal 

92 <A/T> and ground by backprobing.

• Voltage should be between 2.0 and 3.0 volts.

(5) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?

YES : Go to Step 21.
NO :  Go to Step 4.

AC002079 AB

MB991709

MB991658

AC002082

HARNESS SIDE 
CONNECTOR

<A/T> 
C-59

<M/T> 
C-62

AC

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-718

STEP 4. Check connectors C-28, C-90, D-16 at intermediate 
connector and C-62 at ECM <M/T> or C-59 at PCM <A/T> 
for damage.
Q: Are the connectors in good condition?

YES : Go to Step 5.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 22.

AC001741 AJ

CONNECTOR: C-28

AC001991

CONNECTOR: C-90

CONNECTOR
BLOCK (LH)

AI

AC001787AD

CONNECTOR: D-16

AC001689

CONNECTOR: C-62<M/T>, C-59 <A/T>

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

C-62 
<M/T>

C-59 
<A/T>

AP