2006 MITSUBISHI COLT engine

GENERAL INFORMATION
MULTIPOINT FUEL INJECTION (MPI) <4G1>13B-5
List of Component Functions
ECU
NameFunction
Engine-ECUThe signals that are input by the sensors enable the
actuators to be controlled in accordance with the
driving conditions.
Sensor
Ignition switch-IGThis signal indicates the ON/OFF condition of the
ignition switch. When this signal is input, the
engine-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 controls the
fuel injection, throttle valve position, and the injection
timing that are suited for starting the engine.
Air flow sensor This signal, which indicates the intake air flow rate
(mass), is input into the engine-ECU. Based on the
signals from this sensor, the engine-ECU effects fuel
injection control.
Oxygen sensor This sensor, which contains zirconia and platinum
electrodes, detects the level of oxygen concentration
in the exhaust gases. The engine-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 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
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
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.
Throttle position sensor This sensor detects the position of the throttle valve
and inputs it into the engine-ECU. Based on the
voltage that is output by this sensor, the engine-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. Based on the
voltage that is output by this sensor, which
determines the accelerator position (and the intention
of the driver), the engine-ECU effects appropriate
fuel injection and throttle valve position controls.

GENERAL INFORMATION
MULTIPOINT FUEL INJECTION (MPI) <4G1>13B-6
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. The engine-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 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.
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 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.
InjectorThe injectors inject fuel in accordance with the
injection signals received from the engine-ECU.
Ignition coil (with power transistor)Applies ignition coil primary current intermittently in
accordance with the ignition signals received from
the engine-ECU, in order to generate high voltage for
ignition.
Fuel pump relayControls the power supplied to the fuel pump in
accordance with the signals received from the
engine-ECU.
A/C compressor relayControls the operation of the A/C compressor in
accordance with the signals received from the
engine-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.
Alternator G terminalControls the amount of current generated by the
alternator in accordance with the signals received
from the engine-ECU.
Cooling fan control relayControls the speed of the cooling fan in accordance
with the signals received from the engine-ECU.
Throttle valve control servoControls the throttle valve position in accordance with
the signals received from the engine-ECU.
ECU
Name Function

FUEL INJECTION CONTROL
MULTIPOINT FUEL INJECTION (MPI) <4G1>13B-7
FUEL INJECTION CONTROL
M2132003000851
The following control is basically the same as those
of the 4G6-MIVEC engine used in the GRANDIS, the
following improvements have been added.•Fuel pressure control solenoid valve
In accordance with the signal received from the
engine-ECU, the fuel is controlled.
System Configuration Diagram
AK401883AD
Air flow sensor
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)
Engine-
ECU
Injector from
fuel pump
To
fuel tank Fuel pressure regulator
Fuel pressure control
solenoid valve
Oil feed
er con t rol valveThe oil fee der control va lve , which is actuate d by the
signals re
ceived f r om th e eng ine-ECU, co ntrols the
valve timing.
Oxygen sensor he ater Tu rns ON a nd OFF the o x ygen senso r heate r circuit
in
accordan ce wit h the sign als rece ive d from the
en
gine-ECU.
Fuel p r essure control solenoid va lveControls the fue l pressure in a cco rdance with the
signals re
ceived f r om th e eng ine-ECU.
Wa ste g a te solen o id valveControls the boo st pre s sure tha t af fe ct s th e waste
ga
te actuator in accord ance with signals re ceived
from the
engin e -ECU.
ECU
Nam
e Func tion

THROTTLE VALVE OPENING ANGLE CONTROL AND IDLE SPEED CONTROL
MULTIPOINT FUEL INJECTION (MPI) <4G1>13B-8
THROTTLE VALVE OPENING ANGLE CONTROL AND IDLE
SPEED CONTROL
M2132003500209
The following control is basically the same as those
of the 4G1-Non-Turbo engine used in the COLT, the
following improvements have been added.
•Clutch monitor switch
The clutch monitor switch inputs the signal into the
engine-ECU to transmit the information about
whether the clutch pedal is depressed or not. By this
signal, the engine-ECU identifies the clutch pedal is
depressed when the transmission is shifted, and per
-
form the following control. When the clutch pedal is
depressed, the throttle valve is automatically closed
and the ignition timing is retarded at the same time.
System Configuration Diagram
AK401884AF
Motor drive power
supply
(From throttle valve
control servo relay)
Engine-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

IGNITION TIMING AND DISTRIBUTION CONTROL
MULTIPOINT FUEL INJECTION (MPI) <4G1>13B-9
IGNITION TIMING AND DISTRIBUTION CONTROL
M2132005000761
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
Air flow sensor
Intake air temperature sensor
Barometric pressure sensor
Engine coolant temperature
sensor
Camshaft position sensor
Crank angle sensor
Detonation sensor
Ignition switch-ST
Clutch switch
Engine-
ECU
AH

FUEL PRESSURE CONTROL
MULTIPOINT FUEL INJECTION (MPI) <4G1>13B-10
FUEL PRESSURE CONTROL
M2132020000069
Normally, the negative pressure in the intake mani-
fold acts upon the fuel pressure regulator to maintain
the fuel pressure at a constant level with regard to
the pressure inside the intake manifold, causing the
amount of fuel injected to be controlled proportion to
the injector drive time. However, if the engine is
started while the engine coolant temperature and the
intake air temperature are high, the engine-ECU makes current flow to the fuel pressure control sole
-
noid valve to activate the fuel pressure regulator by
means of atmospheric pressure. Because of this, the
generation of fuel vapour due to the high fuel pres
-
sure and high temperature is avoided, and the idling
stability immediately after restarting the engine at
high temperature is maintained.
AK402663
To fuel
tank
From
fuel
pump
Fuel pressure
regulator
Fuel pressure
control solenoid
AB
Engine control
relay
Engine coolant temperature
sensorIntake air temperature
sensor
Engine-ECU
Battery

WASTE GATE CONTROL
MULTIPOINT FUEL INJECTION (MPI) <4G1>13B-11
WASTE GATE CONTROL
M2132013000078
Turbo pressure used in the waste gate actuator is
controlled by duty control of the waste gate solenoid
valve. As a result, turbo pressure corresponding to
driving conditions can be obtained.
AK402657
Waste gate
solenoid valveWaste gate
actuator
Battery Engine-ECU Crank angle sensor
Engine
control relay
Air flow sensor
Air by-pass valve
Air
inlet Intercooler
Turbocharger
AB
AK305437
Solenoid
On SolenoidSpring set pressure
Set pressure Actual turbo
pressure (kPa)
Turbo pressure acting on waste
gate actuator (kPa)
OFFAB
The eng
ine-ECU turns the power tran sistor ON and,
whe
n normal curren t (duty 100% ) flows in th e waste
gate solen
o id valve coil, the waste gat e solenoid valve do es n o t ope n if tu rbo pre ssu re does not rise
above the set pre s sure of th e waste gate actua t or
spring since some of the turb o pressure used in th e
wa ste g a te actuato r leaks o u t.
On the ot
her hand, when current do es not flow in the
wa
ste g a te soleno id valve co il (d uty 0 % ), the wa ste
gate valve ope
ns if turbo pressure rise to the set
pressure o
f the waste gat e act uator sprin g since no
pressure leaks out
.
Conseq uently , by u s in g duty co ntrol for the waste
g
a te solen o id valve, turbo pressu re can b e con t ro lled
in a range
f r om 0% to 1 00% duty . Th is du ty co ntrol is
performed in cycles of
approximately 60ms.

OTHER CONTROL FUNCTIONS
MULTIPOINT FUEL INJECTION (MPI) <4G1>13B-12
OTHER CONTROL FUNCTIONS
M2132010000648
The following controls are basically the same as
those of the 4G1-Non-Turbo engine used in the
COLT.
•ENGINE CONTROL RELAY CONTROL
•THROTTLE VALVE CONTROL SERVO RELAY
CONTROL
•MIVEC (Mitsubishi Innovative Valve Timing Elec-
tronic Control System)
•FUEL PUMP RELAY CONTROL
•OXYGEN SENSOR (front) HEATER CONTROL
•OXYGEN SENSOR (rear) HEATER CONTROL
•FAN RELAY CONTROL
•A/C RELAY CONTROL
•ALTERNATOR CONTROL