
HEATER UNIT
HEATER, AIR CONDITIONER AND VENTILATION55-5
HEATER UNIT
M2551000800219
COOLING UNIT AND HEATER UNIT
AC313940AB
Air intake boxResistor
(Power transistor)*Heater unit
Mode selection
damper
Blower motor
Air mixing
damper motor*
Mode selection
damper
Heater core
Air mixing damper
Evaporator
(Cooling unit)
Outside/Inside air
selection damper
Outside/Inside air selection
damper motor
Clean air filter
NO TE: *: Indicat e s vehicles with a u tomatic A/C.
The following co oling unit and heate r unit have been
inst
alled for grea ter fan p o wer , red u ced noise, an d
imp
r oved A/C p e rformance .
•The h eat er unit int egra t es t he hea ter , b l owe r , and
co
oling unit for re duce d weigh t and size.
•Smaller air int a ke b o x ha s be en ado pted fo r
la
rger p a ssenge r leg sp ace .
•The case has a crush able structure so as to be
crushe
d when a collision occurs, t hereby prote c t
-
ing p a ssenger s from imp a ct an d improving t he
safety
.
•Rehea ting of heat er is minimise d to red u ce A/ C
lo
ad, the r eby imp r oving fue l co nsumption.
•Clean air filter with deod orant function is inst alled
for h
i ghe r comfort.

A/C-ECU
HEATER, AIR CONDITIONER AND VENTILATION55-8
A/C-ECU
M2551001200179
CONTROL SYSTEM
The manual and automatic A/Cs have the following
control functions.
ControlManual A/CAutomatic A/C
Automatic wind temperature change controlApplicableApplicable
Automatic outside/inside air selection controlApplicableApplicable
Idle-up controlApplicableApplicable
Cooling fun load controlApplicableApplicable
Cooling controlApplicableApplicable
Detection control for refrigerant leaksApplicableApplicable
MAX A/C controlNot applicableApplicable
Estimation control for compressor torqueApplicableApplicable
Defroster linked controlNot applicableApplicable
AUTOMATIC CHANGE CONTROL OF
BLOW WIND TEMPERATURE
(COMPRESSOR
ENERGY-CONSERVATION CONTROL)
Optimum ON/OFF control of the compressor is
achieved according to the outside/inside air mode,
air temperature (air temperature sensor), and insula
-
tion.
OUTSIDE/INSIDE AIR AUTO SWITCHING
CONTROL
When the A/C is turned on in high ambient tempera-
ture, the recirculation function is automatically acti-
vated to cool down the passenger compartment and
improve fuel consumption.
COOLING FUN LOAD CONTROL
Depending on the A/C load, the cooling fan cycle
time is controlled and the exterior noise in the inter
-
mediary stage is decreased. Also, the load of the
alternator is decreased to improve the fuel economy.
COOLING CONTROL
If air temperature is high, the CVT rotates at a high
speed to prevent deterioration in cooling perform
-
ance.
DETECTION CONTROL FOR
REFRIGERANT LEAKS
When it is judged from the air temperature (air tem-
perature sensor) and the refrigerant pressure (A/C
pressure sensor) that the refrigerant amount is the
specified value or less, or the refrigerant pressure is
abnormal, the compressor is forced to be cut off to
protect the A/C system.
MAX A/C CONTROL
When MAX COOL position is set, automatically the
mode is changed to the inside air mode before the
A/C is turned ON, thereby facilitating the operation
for obtaining maximum cooling performance.
ESTIMATION CONTROL FOR
COMPRESSOR TORQUE
Communication between the engine⋅CVT-ECU and
A/C-ECU is made to control the engine according to
the compressor torque for higher drivability and
reduction in fuel consumption.
FORCIBLE DEFROSTER CONTROL
When the defroster vents are selected, the A/C is
automatically turned ON. At this time, the out
-
side/inside air selection damper is operated to the
fresh-air position to defrost the windshield glass
quickly.

A/C-ECU
HEATER, AIR CONDITIONER AND VENTILATION55-10
SERVICE DATA OUTPUT
Item No.Check items
02Ambient temperature sensor
03Air thermo sensor
04A/C pressure sensor
05Water temperature sensor
07Set temperature
08Set temperature (control part set value)
15Outside/Inside air selection damper
20Blower motor
21Blower motor (Target)
30A/C switch
31A/C switch (control part set value)
35Rear window defogger switch (control part set value)
36Blower switch
37Outside/Inside air selection switch
40Abnormal low pressure judgement
41Refrigerant leaks judgement
42DEF position flag
43Forcible DEF position flag
44Forcible DEF DRY flag
ACTUATOR TEST
Item No.Check items
30Outside/Inside air selection damper control motor
31
40Rear defogger switch
41
09Condenser fan
0B
50Idle-up requirement
51
52

GROUP 13A
MULTIPOINT FUEL INJECTION (MPI)
<4A9>
CONTENTS
GENERAL INFORMATIO N . . . . . . . .13A-2
FUEL INJECTION CONTROL . . . . . .13A-9
THROTTLE VALVE OPENING
ANGLE CONTROL AND IDLE
SPEED CONTROL . . . . . . . . . . . . . . .13A-10
IGNITION TIMING AND
DISTRIBUTION CONTROL . . . . . . . .13A-11
OTHER CONTROL FUNCTIONS . . . .13A-11
FAN RELAY CONTROL . . . . . . . . . . .13A-12
CONTROLLER AREA NETWORK
(CAN) . . . . . . . . . . . . . . . . . . . . . . . . .13A-13
DIAGNOSIS SYSTEM. . . . . . . . . . . . .13A-14

GENERAL INFORMATION
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-2
GENERAL INFORMATION
M2132000100990
Although the control systems are basically the same
as those of the 4G1-Non-Turbo engine used in the
COLT, the following improvements have been added.
ImprovementRemark
Dual oxygen sensor is used Higher reliability of air-fuel ratio control
Fan relay control is changedAbolish the two stage control of the fan rotating speed.

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
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

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

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