Page 94 of 364
OIL COOLER<4G1>
ENGINE LUBRICATION12-7
OIL COOLER<4G1>
M2120008000020
AK402142
Oil outletOil inlet
To cylinder block
From oil filter
Coolant inlet
(from throttle body)
Coolant outlet
(to water inlet pipe)
Oil cooler boltOil cooler
AC
An
oil cooler is used for the vehicle wit h a turb o-
charge r to improve the per formance of cooling lubri-
cant.
By circulating the coolant an d the o il within t he oil
cooler
, he at is exchang ed an d the o il is coole d .
Page 97 of 364

GENERAL INFORMATION
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-3
SYSTEM BLOCK DIAGRAM
AK600486
Barometric pressure sensorThrottle valve control servo
Manifold absolute pressure
sensor
Engine coolant
temperature sensor
No.1 injector
No.2 injector
No.3 injector
No.4 injector
No.1 Ignition coil
No.2 Ignition coil
No.3 Ignition coil
No.4 Ignition coil
Engine control relay
Throttle valve control servo relay
A/C compressor relay
Fuel pump relay
Alternator G terminal
Cooling fan control relay
Purge control solenoid valve
Diagnostic output terminal
Intake air temperature sensor
Accelerator pedal
position sensor (main) Throttle position sensor (sub)
Camshaft position sensor
Crank angle sensor
Oxygen sensor (front)
Oxygen sensor (rear)
Alternator FR terminal
Inhibitor switch
Detonation sensor
Ignition switch-IG
Ignition switch-ST
Stop lamp switch
Power supply
Accelerator pedel
position sensor (sub) Throttle position sensor (main)
Throttle valve control unitEngine control unit
Engine-ECU or
Engine-CVT-ECU
Throttle opening feedback control Oxygen sensor heater (front)
Oxygen sensor heater (rear)
[1] Fuel injection control
[2] Throttle valve opening control
and idle speed control
[3] MIVEC (Mitsubishi Innovative
Valve timing Electronic
control system)
[4] Ignition timing control
[5] Engine control relay control
[6] Throttle valve control servo
relay control
[7] Fuel pump relay control
[8] Oxygen sensor heater
control
[9] Fan relay control
[10] A/C compressor relay
control
[11] Alternator control
[12] Purge control
[13] EGR control
[14] Diagnostic output
[15] RAM data transmission
Oil feeder control valve
(for MIVEC)
EGR valve
(Stepper motor)
AB
Page 98 of 364

GENERAL INFORMATION
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-4
CONTROL SYSTEM DIAGRAM
AK600525
1 Oxygen sensor
(front)4 Intake air temperature
sensor
3 Manifold absolute
presssure sensor
2 Oxygen sensor (rear) 3 Throttle valve control
servo
10 Throttle position sensor
(main)
2 Purge control
solenoid valve
8 Engine coolant
temperature sensor
9 Detonation sensor
7 Crank angle sensor
6 Camshaft position sensor
4 Oil feeder control valve
1 Injector
AB
M
1 Oxygen sensor (front)
2 Oxygen sensor (rear)
3 Manifold absolute
presssure sensor
4 Intake air temperature
sensor
5 Throttle position
sensor
(sub)
6 Camshaft position
sensor
7 Crank angle sensor
8 Engine coolant
temperature sensor
9 Detonation sensor
10 Throttle position
sensor (main) 1 Injector
2 Purge control
solenoid valve
3 Throttle valve control
servo
4 Oil feeder control
valve
Power supply
Ignition switch-IG
Ignition switch-ST
Accelerator pedal
position sensor
(main)
Accelerator pedal
position sensor
(sub)
Alternator FR
terminal
Stop lamp switchEngine-ECUEngine control relay
Fuel pump relay
A/C compressor relay
Throttle valve
control servo relay
Ignition coil
Cooling fan
control relay
Diagnosis output
Alternator G terminal
Oxygen sensor heater
(front)
Oxygen sensor heater
(rear)
Canister Air
inlet
Catalytic converter From fuel
pump
5 Throttle position sensor
(sub)
Barometric
pressure
sensor
Page 99 of 364

GENERAL INFORMATION
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-5
AK403079
1 Oxygen sensor
(front)4 Intake air temperature
sensor
3 Manifold absolute
presssure sensor
2 Oxygen sensor (rear) 4 Throttle valve control
servo
10 Throttle position sensor
(main)
2 EGR valve
(stepper motor) 3 Purge control
solenoid valve
8 Engine coolant
temperature sensor
9 Detonation sensor
7 Crank angle sensor
6 Camshaft position sensor
5 Oil feeder control valve
1 Injector
AC
1 Oxygen sensor (front)
2 Oxygen sensor (rear)
3 Manifold absolute
presssure sensor
4 Intake air temperature
sensor
5 Throttle position
sensor (sub)
6 Camshaft position
sensor
7 Crank angle sensor
8 Engine coolant
temperature sensor
9 Detonation sensor
10 Throttle position
sensor (main) 1 Injector
2 EGR valve
(stepper motor)
3 Purge control
solenoid valve
4 Throttle valve control
servo
5 Oil feeder control
valve
Power supply
Ignition switch-IG
Ignition switch-ST
Accelerator pedal
position sensor
(main)
Accelerator pedal
position sensor
(sub)
Inhibitor switch
Alternator FR
terminal
Stop lamp switchEngine-
CVT-ECUEngine control relay
Fuel pump relay
A/C compressor relay
Throttle valve
control servo relay
Ignition coil
Cooling fan
control relay
Diagnosis output
Alternator G terminal
Oxygen sensor heater
(front)
Oxygen sensor heater
(rear)
Canister Air
inlet
Catalytic converter From fuel
pump
5 Throttle position sensor
(sub)
Barometric
pressure
sensor
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 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 110 of 364

DIAGNOSIS SYSTEM
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-16
P0606Microcomputer malfunctionAbnormality in engine-ECU
or engine-CVT-ECU ON
P0622Alternator FR terminal systemOpen circuit or short-circuit in
system-related circuits−
P0638*Throttle valve control servo circuit
range/performance problemAbnormal throttle valve control
servoON
P0642*Throttle position sensor power
supplyAbnormality in engine-ECU
or engine-CVT-ECU ON
P0657*Throttle valve control servo relay
circuit malfunctionOpen circuit or short-circuit in
sensor-related circuitsON
P1021Oil feeder control valve systemOpen circuit or short-circuit in
solenoid valve-related circuitsON
P1602*Communication malfunction
(between engine-ECU or
engine-CVT-ECU main
processor and system LSI)Abnormality in engine-ECU
or engine-CVT-ECU ON
P1603*Battery backup circuit malfunctionOpen circuit or short-circuit in
system-related circuitsON
P2100*Throttle valve control servo circuit
(open)Open circuit in throttle valve control
servo-related circuitON
P2101*Throttle valve control servo
magneto malfunctionShort-circuit in system-related
circuitsON
P2108*Throttle valve control servo
processor malfunctionAbnormality in engine-ECU
or engine-CVT-ECU ON
P2122*Accelerator pedal position sensor
(main) circuit low inputOpen circuit or short-circuit in
sensor-related circuitsON
P2123*Accelerator pedal position sensor
(main) circuit high inputOpen circuit in sensor-related
circuitsON
P2127*Accelerator pedal position sensor
(sub) circuit low inputOpen circuit or short-circuit in
sensor-related circuitsON
P2128*Accelerator pedal position sensor
(sub) circuit high inputOpen circuit in sensor-related
circuitsON
P2135*Throttle position sensor (main and
sub) range/performance problemAbnormal sensor outputON
P2138*Accelerator pedal position sensor
(main and sub) range/performance
problemAbnormal sensor outputON
P2226Barometric pressure sensor
systemAbnormality in engine-ECU
or engine-CVT-ECU ON
U1073Bus offAbnormality in CAN bus line−
U1102ABS-ECU time-outAbnormality in CAN bus line−
U1106EPS-ECU time-outAbnormality in CAN bus line−
U1108Combination meter time-outAbnormality in CAN bus lineON
U 111 0A/C-ECU time-outAbnormality in CAN bus line−
Code No. Diagnosis item Main diagnosis contents Engine
warning lamp