Page 100 of 364

GENERAL INFORMATION
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-6
List of Component Functions
NameFunction
ECU
Engine-ECU or engine-CVT-ECU The signals that are input by the sensors enable the
actuators to be controlled in accordance with the
driving conditions.
Sensors
Ignition switch-IGThis signal indicates the ON/OFF condition of the
ignition switch. When this signal is input, the
engine-ECU or engine-CVT-ECU
supplies power to the crank angle sensor, camshaft
position sensor, etc.
Ignition switch-STThis signal indicates that the engine is cranking.
Based on this signal, the engine-ECU or
engine-CVT-ECU controls the fuel injection,
throttle valve position, and the injection timing that
are suited for starting the engine.
Manifold absolute pressure sensor Uses a pressure conversion element to detect the
pressure in the intake manifold, converts it into a
voltage signal, and outputs it to the
engine-ECU or engine-CVT-ECU. The
engine-ECU or engine-CVT-ECU
optimally corrects the fuel injection amount and the
like based on this signal.
Oxygen sensor This sensor, which contains zirconia and platinum
electrodes, detects the level of oxygen concentration
in the exhaust gases. The engine-ECU or
engine-CVT-ECU determines whether the
air-fuel ratio is at the optimal stoichiometric ratio in
accordance with this oxygen concentration level.
Barometric pressure sensorThis sensor detects the altitude of the vehicle. It
enables the engine-ECU or engine-CVT-ECU
to make fuel injection volume corrections in
order to achieve an appropriate air-fuel ratio.
Intake air temperature sensorThis sensor, which contains a thermistor, detects the
temperature of the intake air. The engine-ECU
or engine-CVT-ECU makes fuel injection
volume corrections that suit the intake air
temperature, in accordance with the voltage that is
output by this sensor.
Engine coolant temperature sensorThis sensor, which contains a thermistor, detects the
temperature of the engine coolant. The engine-ECU
or engine-CVT-ECU determines the
warm-up condition of the engine in accordance with
the voltage that is output by this sensor, in order to
control the fuel injection volume, idle speed, and
ignition timing.
Page 101 of 364

GENERAL INFORMATION
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-7
Throttle position sensor This sensor detects the position of the throttle valve
and inputs it into the engine-ECU or
engine-CVT-ECU . Based on the voltage that
is output by this sensor, the engine-ECU or
engine-CVT-ECU effects throttle valve
feedback control.
Accelerator pedal position sensor This sensor detects the position of the accelerator
and inputs it into the engine-ECU or
engine-CVT-ECU . Based on the voltage that
is output by this sensor, which determines the
accelerator position (and the intention of the driver),
the engine-ECU or engine-CVT-ECU
effects appropriate fuel injection and throttle valve
position controls.
Camshaft position sensorThis sensor detects the top-dead-center (TDC) of the
compression stroke of each cylinder.
Crank angle sensorThis sensor detects the crank angle and inputs it into
the engine-ECU or engine-CVT-ECU .
The engine-ECU or engine-CVT-ECU
effects injector control and other controls in
accordance with the signals received from this
sensor.
Detonation sensorThis sensor, which contains a piezoelectric element,
detects the vibration of the cylinder block that results
from knocking. The engine-ECU or
engine-CVT-ECU detects only the knocking
of the engine from these vibrations, in order to retard
the ignition timing in accordance with the strength of
the knocks.
Alternator FR terminalThis terminal is used for detecting the duty cycle ratio
that energizes the alternator field coil.
Inhibitor switch This is a contact point type switch that inputs a signal
into the engine-CVT-ECU to determine whether the
shift lever is in the neutral position.
Stop lamp switchThis is a contact point type switch that detects how
the brake pedal is depressed.
Actuators
Engine control relayThis relay turns ON and OFF the engine-ECU
or engine-CVT-ECU power circuit.
Throttle valve control servo relayThis relay turns ON and OFF the actuation power
circuit for the throttle valve control servo in the
engine-ECU or engine-CVT-ECU .
InjectorThe injectors inject fuel in accordance with the
injection signals received from the engine-ECU
or engine-CVT-ECU .
Ignition coil (with power transistor)Applies ignition coil primary current intermittently in
accordance with the ignition signals received from
the engine-ECU or engine-CVT-ECU ,
in order to generate high voltage for ignition.
Name Function
Page 102 of 364

GENERAL INFORMATION
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-8
Fuel pump relayControls the power supplied to the fuel pump in
accordance with the signals received from the
engine-ECU or engine-CVT-ECU .
A/C compressor relayControls the operation of the A/C compressor in
accordance with the signals received from the
engine-ECU or engine-CVT-ECU .
Purge control solenoid valveControls the flow rate of the purge air introduced into
the inlet manifold in accordance with the signals
received from the engine-ECU or
engine-CVT-ECU .
EGR valve (stepper motor) Controls the EGR flow rate in accordance with the
signals received from the engine-CVT-ECU.
Alternator G terminalControls the amount of current generated by the
alternator in accordance with the signals received
from the engine-ECU or engine-CVT-ECU
.
Cooling fan control relayControls the rotation of cooling the fan in accordance
with the signals received from the engine-ECU
or engine-CVT-ECU .
Throttle valve control servoControls the throttle valve position in accordance with
the signals received from the engine-ECU or
engine-CVT-ECU .
Oil feeder control valveThe oil feeder control valve, which is actuated by the
signals received from the engine-ECU or
engine-CVT-ECU , controls the valve timing.
Oxygen sensor heater Turns ON and OFF the oxygen sensor heater circuit
in accordance with the signals received from the
engine-ECU or engine-CVT-ECU .
Name Function
Page 103 of 364
FUEL INJECTION CONTROL
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-9
FUEL INJECTION CONTROL
M2132003000840
This control system is basically the same as that of
the 4G1-Non-Turbo engine used in the COLT.
System Configuration Diagram
AK600487
Catalytic
converterInjector
From fuel
pump
AB
Manifold absolute pressure sensor
Engine-ECU
or
Engine-CVT-
ECU Barometric pressure sensor
Intake air temperature sensor
Engine coolant temperature sensor
Throttle position sensor
Accelerator pedal position sensor Detonation sensor
Camshaft position sensor Crank angle sensor
Ignition switch-ST Oxygen sensor (front)
Oxygen sensor (rear)
Page 104 of 364
THROTTLE VALVE OPENING ANGLE CONTROL AND IDLE SPEED CONTROL
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-10
THROTTLE VALVE OPENING ANGLE CONTROL AND IDLE
SPEED CONTROL
M2132003500191
These control systems are basically the same as
those of the 4G1- Non-Turbo engine used in the
COLT.
System Configuration Diagram
AK401884AE
Motor drive power
supply
(From throttle valve
control servo relay)
Engine-ECU or
Engine-CVT-ECU
Throttle
position
sensor
Main Sub Sub Main
Throttle valve
control servo Accelerator
pedal position
sensor
Throttle valve control unit
Engine control unit
Motor drive circuit
Page 105 of 364

IGNITION TIMING AND DISTRIBUTION CONTROL
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-11
IGNITION TIMING AND DISTRIBUTION CONTROL
M2132005000750
This control system is basically the same as that of
the 4G1-Non-Turbo engine used in the COLT.
System Configuration Diagram
AK402031
Ignition switch-IG
Ignition
coil Battery
Spark plug
Cylinder No. 1 2 3 4
Manifold absolute
pressure sensor
Intake air temperature sensor
Barometric pressure sensor
Engine coolant
temperature sensor
Camshaft position sensor
Crank angle sensor
Detonation sensor
Ignition switch-ST
Engine-ECU
or Engine-
CVT-ECU
AG
OTHER CONTROL FUNCTI O NS
M21320100 0059 6
The following co ntrols are b a sically t he sa me a s
those
of the 4G1 - No n
−turbo eng ine u s ed in the
CO
L
T
.
•ENGINE CONTROL RELA Y CONTROL
•THROTTLE VA L V E C O NTROL SER VO R E LA Y
CONTROL
•MIVEC (Mitsub i sh i Inno vative V a lve T i ming Elec-
tronic Con t rol System)
•FUEL PUMP RELA Y CONTROL
•OXYGEN S E NSOR HEA T E R CONTR O L
•A/C RELAY CONTROL
•ALTER N A T OR CONTROL
Page 106 of 364
FAN RELAY CONTROL
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-12
FAN RELAY CONTROL
M2132026400117
M
AK402032
OFFON ON
OFF
Engine coolant temperature sensor
Accelerator pedal position sensor Crank angle sensor
Engine-ECU or
Engine-CVT-ECU
Battery
Ignition
switch-IG
Cooling fan
control relay
Cooling fan
control relay A/C switch
AD
A/C switchVehicle speedEngine coolant
temperaturePower transistorFan operation
OFF80 km/h or lessApproximately 96°C
or moreONRotated
Approximately 96°C
or lessOFFStopped
80 km/h or moreApproximately
105
°C or more
ONRotated
Approximately
105
°C or less
OFFStopped
ON−−ONRotated
Page 107 of 364
CONTROLLER AREA NETWORK (CAN)
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-13
CONTROLLER AREA NETWORK (CAN)
M2132019000292
Establishing communication without fail is designed
by CAN communication protocol. Refer to Group
54C-CAN
P.54C-2 for the details about CAN.
The signals input into engine-ECU or
engine-CVT-ECU are as follows:
CAN Communication Input Signal Table
Input signal nameTransmitter ECU
Motor electric current signalEPS-ECU
Compressor signalMeter and A/C-ECU
Idle-up request signal
Cooling fan request signal
SYSTEM CONFIGURATION DIAGRAM
AK600527AB
Engine-ECU
or
Engine-CVT
-ECU
M.U.T.-III
EPS-ECU ETACS
-ECU
Steering
wheel
sensor G and
yaw rate
sensor
ABS-ECU
CAN_H
CAN_L Diagnosis
connector Combination
meter
(incorporating
meter-A/C-ECU)
: Shows sub bus line. : Shows main bus line. Terminal resistor
Terminal resistor
Main bus lines