Mitsubishi Eclipse. Manual - part 538

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-695

 Sensor (The sensors below are determined to be 

normal)

• Volume airflow sensor

• Barometric pressure sensor

• Intake air temperature sensor

• Engine coolant temperature sensor

.

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 20 and 70 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.13B-7

.

.

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.

• ECM <M/T> or PCM <A/T> 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 

AC210306

RANGE CHECK - MIN/MAX

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-696

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 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-697

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-698

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