2008 MITSUBISHI LANCER EVOLUTION X sensor

AUTO-CRUISE CONTROL SYSTEM
ENGINE AND EMISSION CONTROL17-5
CONSTRUCTION AND OPERATIONM2170002000232
SYSTEM OUTLINE
The ECM calculates the auto-cruise control system
operation status when the ECM receives input sig
-
nals from the auto-cruise control switch, vehicle
speed and cancel system [stoplight switch and clutch
switch or transmission range switch ]. The engine control section sends the target acceler
-
ator pedal opening angle value for auto-cruise con-
trol system, the TCM issues a command to transaxle
control , and the gauge issues an ON/OFF
command for the "CRUISE" indicator light.
In the engine control section, the target throttle valve
opening angle value is calculated from the target
accelerator pedal opening angle value for
auto-cruise control system and the actual accelerator
angle value.The vehicle speed is then controlled by
applying the TAC motor.
BLOCK DIAGRAM
Throttle position sensor (TP sensor)Informs the ECM of the throttle valve opening angle.
Transaxle control module (TCM) •Based on the transaxle control signal from the
ECM, it controls the transaxle.
•Outputs the signal from the secondary pulley
speed sensor to the ECM.
•Transmits the selector lever "N" position signal
from the transmission range switch to the ECM.
Vehicle speed sensor Transmits the vehicle speed signal proportional to
the vehicle speed to the ECM.
Component Function
TAC motor Target accelerator
pedal opening
angle signal
Engine control section
Cruise control section"CRUISE" indicator light
AC611103
Actual accelerator
pedal opening
angle signal
Shift control
signal
Target throttle
valve opening
angle signal
Auto-cruise control switch
ECM
Stoplight switch, clutch switch
TCM
"CRUISE"
indicator light
ON/OFF signal
APP sensor
Transmission
range switch
signal Shift control
signal
TransaxleTransmission
range switch
signal
Secondary
pulley speed
sensor signal
ON/OFF
signalON/OFF
signal
Vehicle speed
sensor
Vehicle
speed
signal
Secondary
pulley speed
sensor signal

AUTO-CRUISE CONTROL SYSTEM
ENGINE AND EMISSION CONTROL17-7
FAIL-SAFE FUNCTION
When any of the following conditions are satisfied,
the auto-cruise control system function is stopped
until the system returns to normal. Also, when any of
the conditions are satisfied during the constant
speed driving, the constant speed driving is can
-
celled immediately.
•An abnormality occurs to the auto-cruise control
switch.
•An abnormality occurs to the stoplight switch.
When any of the following conditions are satisfied,
stop the vehicle once and turn the ignition switch to
"LOCK" (OFF). Otherwise, even when the system
returns to normal, the auto-cruise control system
function will continue to be stopped. Also, when any
of the conditions are satisfied during the constant
speed driving, the constant speed driving is can
-
celled immediately.
•ECM abnormality
•TP sensor abnormality
•APP sensor abnormality
.
DIAGNOSIS FUNCTION
•The diagnostic trouble code check is possible
with the "CRUISE" indicator light.
•To facilitate the system check, check the service
data output with the M.U.T.-III.
NOTE: For diagnostic items, service data output
items, and check method, refer to the Service Man
-
ual.

EMISSION CONTROL
ENGINE AND EMISSION CONTROL17-8
EMISSION CONTROL
GENERAL DESCRIPTIONM2171000101024
The following changes have been made to the con-
trols of the 2.4L engine provided on the GALANT.
SYSTEM CONFIGURATION DIAGRAM

Improvement / AdditionsRemark
Addition of HC trap catalytic converter HC decrease
AK604140
Positive crankcase
ventilation valve
Fuel pressure
regulator Evaporative emission
purge solenoid
Evaporative
emission
canisterEvaporative emission
ventilation valve
Fuel level
sensor
Fuel tank differential
pressure sensor
Fuel tank
temperature
sensor Fuel pump
Three-way catalytic converter Heated oxygen
sensor (front)
Heated oxygen
sensor (rear)Fuel tank
AB

EMISSION CONTROL
ENGINE AND EMISSION CONTROL17-9

Exhaust gas cleaning devices list
AK604141
Three-way catalytic converter Heated
oxygen
sensor
(front)
Heated
oxygen
sensor
(rear)
HC trap
catalytic
converterHeated oxygen sensor (3rd)Positive crankcase
ventilation valve
EGR valve
(stepper motor)
AB
Fuel level
sensorFuel
tank
Fuel tank differential
pressure sensor
Fuel tank
temperature
sensor Fuel pump Fuel pressure
regulator Evaporative emission
purge solenoid
Evaporative
emission
canisterEvaporative emission
ventilation valve
SystemObjective / FunctionComposition parts
Crankcase ventilation
systemHC decrease
Re-combustion of blow-by gas.
Positive crankcase ventilation
(PCV) valve
Evaporative emission
control systemHC decrease
Re-combustion of fuel vapor gas.
•Canister
•Evaporative emission purge
solenoid
Exhaust gas recirculation
(EGR) system
NOx decrease
Reduce NOx generation by controlling EGR
volume according to engine warm-up condition
and driving conditions.
EGR valve

EMISSION CONTROL
ENGINE AND EMISSION CONTROL17-10
CRANKCASE VENTILATION SYSTEMM2171000400129
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. 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 crank
-
case. The blow-by gas in the crankcase is induced to
the intake manifold through the rocker cover and
PCV valve. During high load driving, blow-by gas in
the crankcase is induced to the intake manifold
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.
Emission
reduction
systemsAir-fuel ratio
feedback
controlDecrease of CO, HC and NOx
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.
•ECM
•Mass airflow sensor
•Injectors
•Heated oxygen sensor
•Crankshaft position sensor
etc.
Catalytic
converterDecrease 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
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
System Objective / Function Composition parts
AK604142
Air cleaner
PCV valve
AB
Ventilation hose
Breather hose
Flow of blow-by gas and clean air (low load area)
Flow of blow-by gas (high load area)

EMISSION CONTROL
ENGINE AND EMISSION CONTROL17-11
POSITIVE CRANKCASE VENTILATION (PCV)
VA LV E
PCV valve lifts the plunger according to negative pressure in
the intake manifold to create appropriate ventilation for the
crankcase.
EVAPORATIVE EMISSION CONTROL SYSTEMM2171000200147
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
is mixed with intake air and combusted. ECM intro
-
duces optimum HC amount according to driving con-
ditions and so performs duty control on the
evaporative emission purge solenoid. Also, the evap
-
orative emission purge solenoid is closed during
deceleration or immediately after engine start to
restrict change in air-fuel ratio and prevent engine
from stalling.
AK602324AC
Plunger
From
rocker
coverTo intake
manifold
Spring
AK604143
Evaporative emission
purge solenoid
Mass airflow sensor
ECM Intake air temperature sensor
Manifold absolute pressure
sensor
Engine coolant temperature
sensor
Throttle position sensor
Crankshaft position sensorEvaporative emission
canister
AB
MFI relay
Battery

EMISSION CONTROL
ENGINE AND EMISSION CONTROL17-12
EVAPORATIVE EMISSION PURGE SOLENOID
An evaporative emission purge solenoid is installed in the
intake manifold.The evaporative emission purge solenoid con
-
trols 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.
EXHAUST GAS RECIRCULATION (EGR) SYSTEM M2171000300122
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 com
-
bustion 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 step
-
per motor and performs initialization.
AK604745AC
B To canister
To intake manifoldA
AK602245AD
12V
ONOFF
0V100 ms
Evaporative
emission
purge solenoidFrom MFI relay
ECM
AK502987AE
ECMMass airflow sensor
Intake air temperature sensor
Manifold absolute
pressure sensor
Engine coolant
temperature sensor
Throttle position sensor
Crankshaft position sensor BatteryEGR valve
(stepper motor)

EMISSION CONTROL
ENGINE AND EMISSION CONTROL17-15
HEATED OXYGEN SENSOR (3RD)
The heated oxygen sensor (3rd) is installed to the HC trap cat-
alytic converter. The heated oxygen sensor (3rd) detects the
oxygen density of the exhaust gas and outputs the voltage to
the ECM in accordance with the oxygen density.
The ECM uses this output voltage to detect the deterioration of
the HC trap catalytic converter. The structure of the heated oxy
-
gen sensor (3rd) is the same as that of the heated oxygen sen-
sor (rear) installed in the exhaust pipe.
HC TRAP CATALYTIC CONVERTER
DETERIORATION MONITOR
The ECM detects the deterioration of the HC trap catalytic con-
verter.
When reaching the certain operating range, the ECM begins
monitoring the difference in the feedback time between the
heated oxygen sensor (rear) on the upstream of the HC trap
catalyst and the heated oxygen sensor (3rd) on the down
-
stream of the HC trap catalyst. This monitoring allows the ECM
to detect the deterioration of the HC trap catalytic converter.
AK604553
AB
Heated oxygen sensor (3rd)
HC trap catalytic converter
AK604148AB
Heated oxygen sensor (rear) Heated oxygen sensor (3rd)
ECMEngine coolant
temperature sensor
Accelerator pedal
position sensor
Crankshaft position sensor