Mitsubishi Lancer Evolution X. Manual - part 338

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-417

DTC SET CONDITIONS
Logic Flow Chart

Check Conditions

• Engine speed is 3,500 r/min or lower.
• Accelerator pedal is depressed.
• Mass airflow is between 13 and 45 g/sec.
• More than 3.5 seconds have elapsed after the

above-mentioned three conditions have been
met.

• Intake air temperature is higher than −10° C

(14° F).

• Barometric pressure is higher than 76 kPa (22.4

in.Hg).

• Under the closed loop air/fuel ratio control.
• Vehicle speed is 1.5 km/h (1.0 mph) or more.
• The ECM monitors the maximum 5 times per

drive cycle under these conditions.

• Short-term fuel trim is higher than −

20 percent

and lower than +17 percent.

• The cumulative mass airflow is higher than 1,638

Judgement Criterion

• When the monitoring for 10 seconds is carried

out 5 times, the frequency ratio of rear and front
signals is the specified value or more.

NOTE: The specified value varies depending on the
average air flow rate.

FAIL-SAFE AND BACKUP FUNCTION

• None

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function − OBD-II Drive Cycle −

Pattern 3

P.13A-9

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

• Catalytic converter deteriorated.
• Heated oxygen sensor failed.
• Exhaust leak.
• ECM failed.

Start

Monitoring

conditions

Malfunction

Good

End

Yes

Rf > R0

Calculate average frequency

ratio (Rf = Fr/Ff) of specified times

R0: Average threshold value

AK604337

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-418

DIAGNOSIS

Required Special Tools:

• MB991958: Scan tool (M.U.T.-III Sub Assembly)

• MB991824: V.C.I.
• MB991827: USB Cable
• MB991910: Main Harness A

STEP 1. Replace the catalytic converter.
(1) Replace the catalytic converter.
(2) Carry out a test drive with the drive cycle pattern. Refer to

Diagnostic Function − OBD-II Drive Cycle − Pattern 3

P.13A-9

(3) Check the diagnostic trouble code (DTC).
Q: Is DTC P0420 set?

YES : Replace the ECM. When the ECM is replaced,

P.42B-11

or GROUP 42C, ID Codes

Registration Judgment Table <Vehicles with WCM>

P.42C-9

NO : The inspection is complete.

DTC P0441: Evaporative Emission Control System Incorrect Purge Flow

TECHNICAL DESCRIPTION

• ECM detects a stuck open condition of evapora-

tive emission purge solenoid and a stuck closed
condition of evaporative emission ventilation
solenoid by pressure change in fuel tank.

• Stuck open evaporative emission purge solenoid

is judged through monitoring leak of evaporative
emission system.

• Stuck closed evaporative emission ventilation

solenoid is judged after 20 seconds from end of
monitoring leak of evaporative emission system,
or of usual operation of evaporative emission
purge solenoid from ON to OFF.

DESCRIPTIONS OF MONITOR METHODS

Fuel tank pressure decreases largely during

purge-cut.

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)

• Fuel tank differential pressure sensor monitor

AK704277

Evaporative emission
purge solenoid

Connector: B-12

B-12 (B)

AK704278

Evaporative emission
ventilation solenoid

Canister
assembly

Connector: F-23

F-23 (GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-419

Sensor (The sensor below is determined to be

normal)

• Not applicable

DTC SET CONDITIONS

Logic Flow Chart

Check Conditions

• Engine is running.
• ON duty cycle of the evaporative emission purge

solenoid is 0 percent.

• 20 seconds have elapsed since the duty cycle of

the evaporative emission purge solenoid has
turned to 0 percent.

Judgement Criterion

• The pressure in the fuel tank is −1.96 kPa (−

0.58

in.Hg) or less for 0.1 second.

FAIL-SAFE AND BACKUP FUNCTION

• None

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function − OBD-II Drive Cycle −

Pattern 4

P.13A-9

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

• Evaporative emission purge solenoid failed.
• Evaporative emission ventilation solenoid failed.
• Fuel tank differential pressure sensor circuit

related part(s) failed.

AK604338

Good

Malfunction

End

Fuel-tank pressure

< -1.96kPa (-0.58 in. Hg)

Reverting pressure

detected during

evap. monitor?

Start

Yes

Continuous

failure for 100msec

Monitoring conditions for

malfunction detection?

Monitoring conditions for

pass judgement?

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-420

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: V.C.I.
• MB991827: USB Cable
• MB991910: Main Harness A

STEP 1. Using scan tool MB991958, read the diagnostic
trouble code (DTC).

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) Turn the ignition switch to the "ON" position.
(3) Read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC P0451 set?

YES : Refer to DTC P0451 − Fuel Tank Differential Pressure

Circuit Range/Performance Problem

P.13A-456

NO : Go to Step 2.

STEP 2. Using scan tool MB991958, check data list item 52:
Fuel Tank Differential Pressure Sensor.
(1) Turn the ignition switch to the "ON" position.
(2) Remove the fuel cap.
(3) Set scan tool MB991958 to the data reading mode for item

52, Fuel Tank Differential Pressure Sensor.

• The fuel tank differential pressures should be 1,500 and

3,500 millivolts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the fuel tank pressure between 1,500 and 3,500

millivolts?
YES : Go to Step 3.
NO : Refer to DTC P0451 − Fuel Tank Differential Pressure

Circuit Range/Performance Problem

P.13A-456

AC608435

Data link connector

MB991827

MB991824

MB991910

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