Mitsubishi Outlander XL. Manual - part 314

Q:Are there any abnormalities?

YES:

Repair it. Then go to Step 4.

NO:

Go to Step 3.

STEP 3. Check the trouble symptoms.

(1)

Carry out a test drive with the drive cycle pattern. Refer to
Diagnostic Function - OBD-II Drive Cycle - Pattern 3 P.
13Ab-8.

(2)

Check the diagnostic trouble code (DTC).

Q:Is DTC P0401 set?

YES:

Replace the ECM. When the ECM is replaced, register

the ID code. Refer to GROUP 42B, ID Code Registration
Judgment Table <Vehicles with KOS> P.42B-12or GROUP
42C, ID Code Registration Judgment Table <Vehicles with
WCM> P.42C-8. Then go to Step 4.

NO:

It can be assumed that this malfunction is

intermittent. Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points - How to Cope
with Intermittent Malfunctions P.00-15.

STEP 4. 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 - Pattern 3 P.
13Ab-8.

(2)

Check the diagnostic trouble code (DTC).

Q:Is DTC P0401 set?

YES:

Retry the troubleshooting.

NO:

The inspection is complete.

DTC P0421: Warm Up Catalyst Efficiency Below Threshold (bank 1)

M11310100229USA0000010000

TECHNICAL DESCRIPTION

｠

The  signal  from  the  rear  heated  oxygen  sensor
differs  from  the  front  heated  oxygen  sensor,
because  the  catalytic  converter  purifies  exhaust
gas. When the catalytic converter has deteriorated,
the  signal  from  the  front  heated  oxygen  sensor
becomes similar to the rear heated oxygen sensor.

｠

The ECM compares the output of the front and rear
heated oxygen sensor signals.

DESCRIPTIONS OF MONITOR METHODS

Front and rear heated oxygen sensor rich/lean
switching frequencies are nearly equal.

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)

｠

Heated oxygen sensor (front) monitor

｠

Heated oxygen sensor (rear) monitor

｠

Heated oxygen sensor heater (front) monitor

｠

Heated oxygen sensor heater (rear) monitor

｠

Misfire monitor

｠

Fuel system monitor

｠

Air/fuel ratio feedback monitor

Sensor (The sensor below is determined to be
normal)

｠

Mass airflow sensor

｠

Engine coolant temperature sensor

｠

Intake air temperature sensor

｠

Barometric pressure sensor

MULTIPORT INJECTION SYSTEM (MFI) <DIAGNOSIS>

13Ab-451

DIAGNOSTIC TROUBLE CODE PROCEDURES

｠

Throttle position sensor

｠

Accelerator pedal position sensor

DTC SET CONDITIONS

Logic Flow Chart

AK603767 AA00

Yes

Good

Malfunction

Monitoring

conditions

Specified times monitored?

Rf < R1

Rf > R0

End

Start

Calculate frequency of

front oxygen sensor output signal (Ff)

Calculate frequency of

rear oxygen sensor output signal (Fr)

Calculate frequency ratio (Rf = Fr/Ff)

Calculate average frequency

ratio (Rf = Fr/Ff) of specified times

13Ab-452

MULTIPORT INJECTION SYSTEM (MFI) <DIAGNOSIS>

DIAGNOSTIC TROUBLE CODE PROCEDURES

Check Conditions

｠

Engine speed is lower than 3,000 r/min.

｠

Accelerator pedal is open.

｠

Mass airflow is between 10 and 35 g/sec.

｠

More than 3 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 PCM monitors for this condition for 3 cycles of
12 seconds each during the drive cycle.

｠

Short-term fuel trim is higher than -25 percent and
lower than +25 percent.

｠

The cumulative mass airflow is higher than 1,638 g.

Judgement Criterion

｠

When the monitoring for 12 seconds is carried out
5 times, the frequency ratio of rear and front is 0.7
or more.

OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle -
Pattern 4 P.13Ab-8.

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

｠

Catalytic converter deteriorated (Exhaust leak).

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 right bank side 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 4 P.
13Ab-8.

(3)

Check the diagnostic trouble code (DTC).

Q:Is DTC P0421 set?

YES:

Replace the ECM. When the ECM is replaced, register

the ID code. Refer to GROUP 42B, ID Code Registration
Judgment Table <Vehicles with KOS> P.42B-12or GROUP
42C, ID Code Registration Judgment Table <Vehicles with
WCM> P.42C-8.

NO:

The inspection is complete.

DTC P0431: Warm Up Catalyst Efficiency Below Threshold (bank 2)

M11310100230USA0000010000

TECHNICAL DESCRIPTION

｠

The ECM compares the output of the front and rear
heated oxygen sensor signals.

DESCRIPTIONS OF MONITOR METHODS

Front and rear heated oxygen sensor rich/lean
switching frequencies are nearly equal.

MULTIPORT INJECTION SYSTEM (MFI) <DIAGNOSIS>

13Ab-453

DIAGNOSTIC TROUBLE CODE PROCEDURES

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)

｠

Heated oxygen sensor (front) monitor

｠

Heated oxygen sensor (rear) monitor

｠

Heated oxygen sensor heater (front) monitor

｠

Heated oxygen sensor heater (rear) monitor

｠

Misfire monitor

｠

Fuel system monitor

｠

Air/fuel ratio feedback monitor

Sensor (The sensor below is determined to be
normal)

｠

Mass airflow sensor

｠

Engine coolant temperature sensor

｠

Intake air temperature sensor

｠

Barometric pressure sensor

｠

Throttle position sensor

｠

Accelerator pedal position sensor

13Ab-454

MULTIPORT INJECTION SYSTEM (MFI) <DIAGNOSIS>

DIAGNOSTIC TROUBLE CODE PROCEDURES

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