Mitsubishi Outlander XL. Manual - part 1260

System

Objective / Function

Composition parts

Controls  air-fuel  ratio  of  air-fuel
mixture to become theoretical air-
fuel  ratio  (about  14.7),  which  is
when

 the

 3-way

 catalytic

converter's cleaning performance
is  best.  It  also  controls  optimum
fuel  supply  based  on  coolant
temperature,  driving  conditions
etc.

Catalytic
converter

Decrease of CO, HC and NOx
It  facilitates  oxidation  of  CO  and
HC and reduction of NOx so that
all  3  component  gases  are
cleaned simultaneously.

Monolith catalyst

HC

 trap

catalytic
converter
<California>

HC decrease
During  cold  operation  of  engine,
exhaust

 HC

 is

 temporarily

absorbed. And then Exhaust HC is
released

 when

 temperature

reaches to level at which catalyst
is activated. This allows HC to be
reduced.

Monolith catalyst

CRANKCASE VENTILATION SYSTEM

M21701000004USA0000010000

ZK602752 AA00

Ventilation hose

Breather hose

Air cleaner

PCV valve

Flow of blow-by gas and clean air (low load area)

Flow of blow-by gas (high load area)

17c-4

EMISSION CONTROL

CRANKCASE VENTILATION SYSTEM

A blow-by gas reduction device prevents blow-by gas
from  being  expelled  into  the  atmosphere  and  is  of
closed  type.  A  positive  crankcase  ventilation  (PCV)
valve  is  provided  in  the  ventilation  hose  from  the
rocker  cover  to  the  intake  manifold  plenum.  During
low load driving, clean air is supplied to the crankcase
by the air intake hose via the breather hose and rocker
cover,  and  it  mixes  with  the  blow-by  gas  in  the

crankcase.  The  blow-by  gas  in  the  crankcase  is
induced  to  the  intake  manifold  plenum  through  the
rocker cover and PCV valve. During high load driving,
blow-by gas in the crankcase is induced to the intake
manifold plenum through the rocker cover and PCV
valve and at the same time also via the air intake hose
and throttle body due to negative pressure in the air
cleaner.

POSITIVE CRANKCASE VENTILATION (PCV)

VALVE

ZK600307AA00

Spring

From
rocker
cover

To inlet
manifold
plenum

Plunger

PCV valve lifts the plunger according to negative pressure at the
intake manifold plenum to create appropriate ventilation for the
crankcase.

EVAPORATIVE EMISSION CONTROL SYSTEM

M21701000002USA0000010000

ZK602753

 ECM

Evaporative
emission purge
solenoid

Evaporative
emission canister

MFI relay

Mass airflow sensor

Intake air temperature
sensor

Engine coolant
temperature sensor

Throttle position sensor

Crankshaft position sensor

Manifold absolute
pressure sensor

Battery

AA00

HC  (hydrocarbon)  generated  in  the  fuel  tank  are
adsorbed  by  the  active  carbon  in  the  canister  and
stored. HC stored in the canister is introduced to the
intake manifold when engine is in operation where it

EMISSION CONTROL

17c-5

EVAPORATIVE EMISSION CONTROL SYSTEM

is  mixed  with  intake  air  and  combusted.  ECM
introduces optimum HC amount according to driving
conditions  and  so  performs  duty  control  on  the
evaporative  emission  purge  solenoid.  Also,  the

evaporative emission purge solenoid is closed during
deceleration  or  immediately  after  engine  start  to
restrict  change  in  air-fuel  ratio  and  prevent  engine
from stalling.

EVAPORATIVE EMISSION PURGE SOLENOID

ZK602524

A

B

To throttle body

To canister

AA00

An evaporative emission purge solenoid is installed in the intake
manifold.The evaporative emission purge solenoid controls the
intake  volume  of  fuel  vapor  gas  from  the  canister.  The
evaporative  emission  purge  solenoid  is  a  duty  control  type
solenoid  valve.  When  current  is  not  passing  through  the  coil,
nipple A is kept airtight and fuel vapor gas cannot be sucked in.
When  current  passes  through  the  coil,  air  can  pass  between
nipple A and B and fuel vapor gas is sucked in. ECM changes
the ON duty ratio according to engine's operating condition to
control the intake volume of fuel vapor gas.

ZK600276

12 V

ON

OFF

0 V

100 ms

AA01

Evaporative
emission
purge solenoid

ECM

From MFI relay

17c-6

EMISSION CONTROL

EVAPORATIVE EMISSION CONTROL SYSTEM

EXHAUST GAS RECIRCULATION (EGR) SYSTEM

M21701000003USA0000010000

ZK602754

 ECM

Mass airflow sensor

Intake air temperature
sensor

Engine coolant
temperature sensor

Throttle position sensor

Crankshaft position sensor

Manifold absolute
pressure sensor

Battery

AA00

EGR valve
(stepper moter)

When  the  combustion  gas  temperature  becomes
high,  generation  of  the  environment  polluting  NOx
(nitrogen  oxides)  increases  rapidly.  EGR  system  is
used to decrease the volume of NOx generated. EGR
system  re-circulates  exhaust  gas  inside  the  intake
manifold. It increases specific heat of the combustion
gases  and  reduces  combustion  speed  to  lower  the

combustion  temperature  and  reduce  the  volume  of
NOx generated. ECM calculates the EGR introduction
volume according to engine operating conditions and
controls  the  EGR  valve  opening  angle  at  optimum.
Also, immediately after the ignition switch ON signal
is  input,  it  drives  fully  closed  stepper  motor  and
performs initialization.

EMISSION CONTROL

17c-7

EXHAUST GAS RECIRCULATION (EGR) SYSTEM