Mitsubishi Evolution X. Manual — part 121
SENSOR
TSB Revision
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 shaft
Hall 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
TSB Revision
MULTIPORT FUEL SYSTEM (MFI)
13A-14
.
HEATED OXYGEN SENSOR
Heated oxygen sensors are installed in the front exhaust pipe
and in the catalytic converter. Heated oxygen sensor has a
built-in heater to help early activation of the sensor. This allows
feedback 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
AK602262AC
0.8
14
15
16
Theoretical air fuel ratio
Electro motive
force (V)
Rich
Lean
Air fuel ratio
SENSOR
TSB Revision
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 intake 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
signal) that is output to ECM. ECM uses crankshaft position
sensor's output pulse to detect crankshaft position.
.
AK602263AC
100
0
HC
CO
NOx
50
Purge ratio
Theoretical air fuel ratio
AK602576AC
From MFI relay
Heated xygen sensor
Heater
Zirconia element
ECM
0.5V
AK703135 AD
Crankshaft
position
sensor
Crankshaft sensing ring
(36 teeth including 3 missing teeth)
SENSOR
TSB Revision
MULTIPORT FUEL SYSTEM (MFI)
13A-16
The crankshaft position sensor uses a magnetic resistance ele-
ment. When the vane of the crankshaft-sensing ring 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 ring 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 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 intake
side of the cylinder head. The intake camshaft position sensor
monitors 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 opti-
mize the phase of the intake camshaft. Also, ECM uses a com-
bination 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
Vane
Magnetic resistance element
Magnetic resistance element
Magnet flux
Magnet flux
AK602285AC
5V
5V
Crankshaft position sensor
ECM
Output signal
Magnetic resistance element
AK602738AC
Camshaft
Sensing portion
Camshaft position sensor
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст