Mitsubishi Eclipse. Manual - part 239

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-449

STEP 18. Check the camshaft position sensing cylinder.
Q: Is the camshaft position sensing cylinder in a good 

condition?
YES : Replace the camshaft position sensor. Then go to 

Step 19.

NO :  Repair it. Then go to Step 19.

STEP 19. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− OBD-II Drive Cycle − Procedure 6 − 

Other Monitor 

P.13A-5

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0340 set?

YES : Retry the troubleshooting.
NO :  The inspection is complete.

DTC P0401: EGR Flow Insufficient Detected

.

TECHNICAL DESCRIPTION

• When the EGR vacuum regulator solenoid valve 

switches from "OFF" to "ON" while the engine is 
running, EGR gas flows.

• The ECM <M/T> or PCM <A/T> checks how the 

EGR gas flow signal changes.

.

DESCRIPTIONS OF MONITOR METHODS
Small manifold pressure change during exhaust gas 

recirculation (EGR) operation from closed to 
open.

.

MONITOR EXECUTION
Continuous

.

MONITOR EXECUTION CONDITIONS (Other 
monitor and Sensor)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• EGR stepper motor monitor

Sensor (The sensor below is determined to be 

normal)

• Volume airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

• Barometric pressure sensor

• Throttle position sensor

• Manifold absolute pressure sensor

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-450

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• At least 20 seconds have passed since the last 

monitor was complete.

• Engine coolant temperature is higher than 76°C 

(169

°F).

• Engine speed is at between 1,000 and 2,000 

<M/T> or 940 and 2,000 <A/T> r/min.

• Intake air temperature is higher than -10°C 

(14

°F).

• Barometric pressure is higher than 76 kPa (22.4 

in.Hg).

• Vehicle speed is 1.5 km/h (1 mph) <M/T> or 30 

km/h (19 mph) <A/T> or more.

• At least 90 seconds have passed since manifold 

absolute pressure sensor output voltage fluctu-
ated 1.5 volts or more.

• The throttle valve is closed.

• Volumetric efficiency is lower than 15 <M/T> or 

24 <A/T> percent.

• While fuel is being shut off. <M/T>

• The ECM<M/T> or PCM<A/T> monitors for this 

condition for 3 cycles of 2 second each during the 
drive cycle.

START

END

NO

NO

NO

YES

YES

YES

MALFUNCTION

GOOD

MONITORING

CONDITIONS

MEASURE MANIFOLD

PRESSURE (P1)

MEASURE MANIFOLD

PRESSURE (P2)

EGR VALVE OPEN

P2 - P1 < P0 *

SPECIFIED TIMES

AK204016

P0 : THRESHOLD VALUE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-451

Judgement Criteria

• When intake manifold pressure fluctuation width 

is lower than 2.9 kPa (0.9 in.Hg). When the EGR 
regulator solenoid valve is turned ON.

.

OBD-ll DRIVE CYCLE PATTERN
Refer to Diagnostic Function 

− OBD-ll Drive Cycle − 

Procedure 5 

− Exhaust Gas Recirculation (EGR) 

System Monitor 

P.13A-5

.

.

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

• EGR valve does not open.

• EGR control vacuum is too low.

• EGR vacuum regulator solenoid valve failed.

• Manifold absolute pressure sensor failed.

• ECM failed. <M/T>

• PCM failed. <A/T>

DIAGNOSIS

Required Special Tools:

• MB991958 (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991911: Main Harness B

STEP 1. Check the EGR system.
Refer to GROUP 17, Emission Control System 

− Exhaust Gas 

Recirculation (EGR) System 

− EGR System Check 

P.17-112

.

Q: Are there any abnormalities?

YES : Repair it. Then go to Step 3.
NO :  Go to Step 2.

STEP 2. Using scan tool MB991958, check data list item 95: 
Manifold Absolute 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) Start the engine and run at idle.
(3) Set scan tool MB991958 to the data reading mode for item 

95, Manifold Absolute Pressure Sensor.

(4) Warm-up the engine to normal operating temperature: 80

°C 

to 96

°C (176°F to 205°F).

• Should be between 65 − 78 kPa at engine idling.

(5) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : Clean the EGR valve and EGR passage. Then go to 

Step 3.

NO :  Refer to DTC P0106 

− Manifold Absolute Pressure 

Sensor Circuit Range/Performance Problem 

P.13A-53

, DTC P0107 

− Manifold Absolute Pressure 

Sensor Circuit Low Input 

P.13A-68

, DTC P0108 

− 

Manifold Absolute Pressure Sensor Circuit High Input 

P.13A-89

.

AK300810

AB

MB991911

16-PIN

MB991827

MB991824 

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-452

STEP 3. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− OBD-II Drive Cycle − Procedure 5 − 

Exhaust Gas Recirculation (EGR) System Monitor 

P.13A-5

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0401 set?

YES : Retry the troubleshooting.
NO :  The inspection is complete.