Mitsubishi Outlander (2003+). Manual - part 149

EMISSION CONTROL <MPI>

ENGINE AND EMISSION CONTROL

17-15

CRANKCASE EMISSION CONTROL 
SYSTEM

GENERAL INFORMATION (CRANKCASE 
EMISSION CONTROL SYSTEM)

M1173005000334

The crankcase emission control system prevents 
blow-by gases from escaping inside the crankcase 
into the atmosphere.
Fresh air is sent from the air cleaner into the 
crankcase through the breather hose.

The air becomes mixed with the blow-by gases 
inside the crankcase.
The blow-by gas inside the crankcase is drawn into 
the intake manifold through the positive crankcase 
ventilation (PCV) valve.
The PCV valve lifts the plunger according to the 
intake manifold vacuum so as to regulate the flow of 
blow-by gas properly.
In other words, the blow-by gas flow is regulated 
during low load engine operation to maintain engine 
stability, while the flow is increased during high load 
operation to improve the ventilation performance.

SYSTEM DIAGRAM

COMPONENT LOCATION (CRANKCASE 
EMISSION CONTROL SYSTEM)

M1173007400242

AK204365

Air cleaner

Air

Ventilation hose

Breather hose

PCV valve

AB

AK204366AD

PCV valve

<4G63>

AK302826

PCV valve

<4G69>

AB

EMISSION CONTROL <MPI>

ENGINE AND EMISSION CONTROL

17-16

POSITIVE CRANKCASE VENTILATION 
SYSTEM CHECK

M1173001100221

1. Remove the ventilation hose from the PCV valve.
2. Remove the PCV valve from the rocker cover.
3. Reinstall the PCV valve at the ventilation hose.
4. Start the engine and run at idle.

5. Place a finger at the opening of the PCV valve 

and check that vacuum of the intake manifold is 
felt.
NOTE: At this moment, the plunger in the PCV 
valve moves back and forth.

6. If vacuum is not felt, clean the PCV valve or 

replace it.

POSITIVE CRANKCASE VENTILATION 
(PCV) VALVE CHECK

M1173001200217

1. Insert a thin rod into the PCV valve from the side 

shown in the illustration (rocker cover installation 
side), and move the rod back and forth to check 
that the plunger moves.

2. If the plunger does not move, there is a clogging 

in the PCV valve. In this case, clean or replace 
the PCV valve.

AK300021

PCV valve

AC

AK300022

PCV valve

AC

EMISSION CONTROL <MPI>

ENGINE AND EMISSION CONTROL

17-17

EVAPORATIVE EMISSION CONTROL 
SYSTEM

GENERAL INFORMATION (EVAPORATIVE 
EMISSION CONTROL SYSTEM)

M1173005100427

The evaporative emission control system prevents 
fuel vapours generated in the fuel tank from escaping 
into the atmosphere.
Fuel vapours from the fuel tank flow through the fuel 
tank pressure control valve and vapour pipe/hose to 
be stored temporarily in the canister.

When driving the vehicle, fuel vapours stored in the 
canister flow through the gurge control solenoid 
valve and purge port and go into the intake manifold 
to be sent to the combustion chamber.
When the engine coolant temperature is low or when 
the intake air quantity is small (when the engine is at 
idle, for example), the engine control unit turns the 
purge solenoid off to shut off the fuel vapour flow to 
the intake manifold.
This does not only insure the driveability when the 
engine is cold or running under low load but also 
stabilize the emission level.

SYSTEM DIAGRAM
<4G63>

AK204367AB

Throttle body

Canister

From
fuel
tank

OFF

ON

Purge
control
Solenoid
valve

Control
relay

Battery

Engine-ECU

Air flow sensor

Engine coolant
temperature sensor

Intake air
temperature sensor

Barometric pressure
sensor

EMISSION CONTROL <MPI>

ENGINE AND EMISSION CONTROL

17-18

<4G69>

COMPONENT LOCATION (EVAPORATIVE 
EMISSION CONTROL SYSTEM) 

M1173007500238

PURGE CONTROL SYSTEM CHECK

M1173001400318

<4G63>

1. Disconnect the vacuum hose (red stripe) from 

throttle body and connect it to a hand vacuum 
pump.

2. Plug the nipple from which the vacuum hose was 

removed.

3. When the engine is cold or hot, apply a vacuum of 

53 kPa, and check the condition of the vacuum.

AK302829AB

Intake manifold

Canister

From
fuel
tank

OFF

ON

Purge
control
Solenoid
valve

Control
relay

Battery

Engine-ECU <M/T> or
Engine-A/T-ECU <A/T>

Air flow sensor

Engine coolant
temperature sensor

Intake air
temperature sensor

Barometric pressure sensor
(with engine-ECU <M/T>
or engine-A/T-ECU <A/T>)

AK201217

Purge control
solenoid valve

AD

<4G63>

AK302830

<4G69>

Purge control
solenoid valve

AB

AK201220

Vacuum hose

Plug

AC