2008 MITSUBISHI LANCER EVOLUTION X Workshop Manual

SENSOR
MULTIPORT FUEL SYSTEM (MFI)13A-12
.
ACCELERATOR PEDAL POSITION SENSOR
Accelerator pedal position sensor is integrated with accelerator
pedal, and detects accelerator opening angle. ECM uses the
output voltage of this sensor to control appropriate throttle
valve opening angle and fuel injection volume. This accelerator
pedal position sensor uses Hall IC and is a non-contact type.
.
AK602222AE
5V 5VThrottle position sensor
Throttle valve opening angle
5
2.54.5
0.5
0 Throttle position
sensor (main)
Throttle position
sensor (sub) Throttle position
sensor (sub)
Throttle position
sensor (main) Hall IC
Fully
closedFully
opened Hall IC
Output voltage V
ECM
AK602569AC
Accelerator pedal position
sensor connector
Accelerator pedal arm

SENSOR
MULTIPORT FUEL SYSTEM (MFI)13A-13
STRUCTURE AND SYSTEM
Accelerator pedal position sensor is composed of a permanent
magnet fixed on the magnet carrier of the pedal shaft, Hall IC
outputs voltage according to magnetic flux density and a stator
that efficiently introduces magnetic flux from the permanent
magnet to Hall IC.
Magnetic flux density at Hall IC is proportional to the output
voltage.
The accelerator pedal position sensor has 2 output systems −
accelerator pedal position sensor (main) and accelerator pedal
position sensor (sub), and the output voltage is output to ECM.
According to depression of the accelerator pedal, output volt
-
age of the accelerator pedal position sensor (main) and accel-
erator pedal position sensor (sub) changes. This allows ECM to
detect the actual accelerator pedal depression amount. ECM
uses accelerator pedal position sensor (main) output voltage
for appropriate throttle valve opening angle control and fuel
injection volume control. Also, ECM compares output voltage of
the accelerator pedal position sensor (main) and accelerator
pedal position sensor (sub) to check for abnormality in sensor.
The relationship between accelerator opening angle and output
voltage of the accelerator pedal position sensor (main) and
accelerator pedal position sensor (sub) is as shown in the fig
-
ure below.
AK602570AC
Magnet
Pedal shaftHall IC
AK602571
S N
S N N S
N S
AC
Hall IC
Hall IC Magnetic flux density
: minimum
Magnetic flux density
: maximum
Magnetic flux

SENSOR
MULTIPORT FUEL SYSTEM (MFI)13A-14
.
HEATED OXYGEN SENSOR (except centor
exhaust pipe heated oxygen sensor )
Heated oxygen sensors are installed in 2 positions (front, rear)
on the catalytic converter. Heated oxygen sensor has a built-in
heater to help early activation of the sensor. This allows feed
-
back control of air-fuel ratio soon after engine start.
.
This sensor uses the oxygen concentration cell principle of
solid electrolyte (zirconia) and displays the property of sudden
change in output voltage near theoretical air-fuel ratio. This
property is used to detect oxygen density in exhaust gas. Feed
-
back to ECM allows it to judge whether air-fuel ratio is rich or
lean compared to theoretical air-fuel ratio.
AK602211
5V 5V
5
4
3
2
1
0
AE
Accelerator pedal position sensor
Accelerator pedal
position sensor (main)
Accelerator pedal
position sensor (main)
Accelerator
pedal stroke Accelerator pedal
position sensor (sub)
Accelerator pedal
position sensor (sub) Hall IC Hall IC
Fully
opened
Output voltage V
ECM
AK602572 AC
Sensing area
AK602262
AC
0.8
14 15 16Theoretical air fuel ratio Electro motive
force (V)
Rich Lean
Air fuel ratio

SENSOR
MULTIPORT FUEL SYSTEM (MFI)13A-15
This allows ECM precise feedback control to get theoretical
air-fuel ratio with best cleaning efficiency of 3-way catalytic con
-
verter.
.
CRANKSHAFT POSITION SENSOR
A crankshaft position sensor is installed on the right side of the
cylinder block. The crankshaft position sensor monitors rotation
of crankshaft sensing ring (36 teeth including 3 missing teeth)
installed on the crankshaft and converts to voltage (pulse sig
-
nal) that is output to ECM. ECM uses crankshaft position sen-
sor's output pulse to detect crankshaft position.
.
AK602263AC
100
0HC
CONOx 50 Purge ratio
Theoretical air fuel ratio
AK602576AC
From MFI relay
Heated xygen sensor
Heater
Zirconia elementECM
0.5V
AK602737AC
Crankshaft
position
sensor Crankshaft sensing ring
(36 teeth including 3 missing teeth)

SENSOR
MULTIPORT FUEL SYSTEM (MFI)13A-16
The crankshaft position sensor uses a magnetic resistance ele-
ment. When the vane of the crankshaft-sensing blade passes
the front surface of the magnetic resistance element, the flux
from the magnet passes the magnetic resistance element.
Thus, resistance of the magnetic resistance element increases.
When the vane of the crankshaft-sensing blade does not pass
the front surface of the magnetic resistance element, the flux
from the magnet does not pass the magnetic resistance ele
-
ment and the resistance decreases. The crankshaft position
sensor converts this change in resistance of the magnetic
resistance element to a 5 V pulse signal and outputs it to ECM.
.
INTAKE CAMSHAFT POSITION SENSOR
The intake camshaft position sensor is installed on the left side
of the cylinder head. The intake camshaft position sensor mon
-
itors shape of the half-moon sensing portion and converts to
voltage (pulse signal) that is output to ECM. Upon receiving this
output voltage, the ECM effects feedback control to optimize
the phase of the intake camshaft. Also, ECM uses a combina
-
tion of the intake camshaft position sensor output pulse signal
and crankshaft position sensor output pulse signal to identify
cylinders in the compression process.
AK602265AC
Crank shaft sensing ring
Crank shaft sensing ring Vane
VaneMagnetic resistance element
Magnetic resistance elementMagnet flux
Magnet flux
AK602285AC
5V5V Crankshaft position sensorECM
Output signal Magnetic resistance element
AK602738AC
Camshaft Sensing portionCamshaft position sensor

SENSOR
MULTIPORT FUEL SYSTEM (MFI)13A-17
The intake camshaft position sensor uses a magnetic resis-
tance element. When the camshaft position sensing portion
passes the front surface of the magnetic resistance element,
the flux from the magnet passes the magnetic resistance ele
-
ment. Thus, resistance of the magnetic resistance element
increases. When the camshaft position sensing portion does
not pass the front surface of the magnetic resistance element,
the flux from the magnet does not pass the magnetic resistance
element and the resistance decreases. The intake camshaft
position sensor converts this change in resistance of the mag
-
netic resistance element to a 5 V pulse signal and outputs it to
ECM
.
EXHAUST CAMSHAFT POSITION SENSOR
The exhaust camshaft position sensor is installed on the right
side of the cylinder head. The exhaust camshaft position sen
-
sor monitors shape of the half-moon sensing portion and con-
verts to voltage (pulse signal) that is output to ECM. Upon
receiving this output voltage, the ECM effects feedback control
to optimize the phase of the exhaust camshaft. The structure
and system of this sensor are basically the same as intake
camshaft position sensor.
.
.
KNOCK SENSOR
A knock sensor is installed on the left side of the cylinder block.
Knock sensor uses the piezoelectric element to convert the
vibration of the cylinder block generated when engine is in
operation to minute voltage that is output to ECM. ECM uses
the minute output voltage from the knock sensor filtered
through the cylinder block's natural frequency to detect knock
-
ing, and compensates the ignition timing lag according to the
strength of the knocking.
AK602574AC
Camshaft position sensing portion
Camshaft position sensing portionMagnetic resistance element
Magnetic resistance elementMagnet flux
Magnet flux
AK602287
5V5V Camshaft position sensorECM
Output signal Magnetic resistance element
AC
AK602739
Piezoelectric element
AC

SENSOR
MULTIPORT FUEL SYSTEM (MFI)13A-18
.
BAROMETRIC PRESSURE SENSOR
A barometric pressure sensor is built into ECM. The barometric
pressure sensor is a semiconductor diffused pressure element
which outputs voltage to ECM according to atmospheric pres
-
sure. ECM uses this output voltage to sense the altitude of the
vehicle and compensates fuel injection volume to achieve the
appropriate air-fuel ratio for that altitude.
.
ENGINE OIL PRESSURE SWITCH
The engine oil pressure switch is installed on the left side of the
cylinder block. The engine oil pressure switch detects whether
the oil pressure is high or low using the contact switch. When
the oil pressure becomes higher than the specified value after
the engine starts, the contact point of the engine oil pressure
switch opens. This allows the ECM to detect the oil pressure is
higher than the specified value. The ECM outputs the OFF sig
-
nal to the combination meter through the CAN and then turns
off the oil pressure warning lamp.
AK602226AD
5V
Knock sensor
Piezoelectric elementECM
AK602575AC
Barometric pressure sensor
(built in ECM)
AK602587AC
Oil
pressure
Contact switch

SENSOR
MULTIPORT FUEL SYSTEM (MFI)13A-19
.
POWER STEERING PRESSURE SWITCH
A power steering pressure switch is installed on the power
steering oil pump. The power steering pressure switch uses a
contact switch to detect the power steering oil pressure. When
power steering oil pressure rises due to operation of the steer
-
ing wheel, the power steering load switch outputs an ON signal
to ECM. ECM performs idle-up according to the voltage and
prevents reduction in engine speed due to power steering load
and so maintains stable idle speed.
.
AK602228
ON
OFF
AD
12
0ONOFF ECM terminal voltage V
Oil pressure:lowOil pressure: high Operating pressure
Oil pressure kPa (in.Hg) Engine oil
pressure switch
ECM
AK601174AF
Power steering
pressure switch
Oil
pressure
AK602213
ON
OFF
AE
Oil pressure:low
Oil pressure: highOperating pressure
Power steering
pressure switch12
0OFF
ON
ECM
ECM
terminal voltage V
Oil pressure kPa (in.Hg)