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.
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
GENERAL INFORMATION
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-6
List of Component Functions
NameFunction
ECU
Engine-ECU
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
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
engine-CVT-ECU
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
engine-ECU
optimally corrects the fuel injection amount and the
like based on this signal.
Oxygen sensor
electrodes, detects the level of oxygen concentration
in the exhaust gases. The engine-ECU
engine-CVT-ECU
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
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
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
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.
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
Engine-CVT-
ECU
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)
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
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
DIAGNOSIS SYSTEM
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-14
DIAGNOSIS SYSTEM
M2132009000882
Engine-ECU
been provided with the following functions for easier
system inspection.FREEZE-FRAME DATA
When the engine-ECU
diagnosis code, the engine condition at that time is
also memorized. The M.U.T.-III can then be used to
analyze this data in order to increase the effective
-
ness of troubleshooting. The freeze-frame data dis-
play items are given below.
Item No.DataUnit
13Intake air temperature sensor°C
21Engine coolant temperature sensor°C
22Crank angle sensorr/min
24Vehicle speed sensorkm/h
32Manifold absolute pressure sensorkPa
44Ignition advancedeg
81Long-term fuel compensation%
82Short-term fuel compensation%
87Calculated load value%
88Fuel control conditionOpen loopOL
Closed loopCL
Open loop owing to drive conditionOL-DRV
Open loop owing to system malfunctionOL-SYS
Closed loop based on one oxygen sensorCL-HO2S
8AThrottle position sensor (main)%
A1Oxygen sensor (front)V
A2Oxygen sensor (rear)V
DIAGNOSIS CODE
The diagnosis and engine warning lamp items are
given in the table below.
Code No.Diagnosis itemMain diagnosis contentsEngine
warning lamp
P0011Variable valve timing systemAbnormal MIVEC system−
P0105Manifold absolute pressure sensor
systemOpen circuit or short-circuit in
sensor-related circuitsON
P0110Intake air temperature sensor
systemOpen circuit or short-circuit in
sensor-related circuitsON
P0115Engine coolant temperature sensor
systemOpen circuit or short-circuit in
sensor-related circuitsON
P0122*Throttle position sensor (main)
circuit low inputOpen circuit or short-circuit in
sensor-related circuitsON
P0123*Throttle position sensor (main)
circuit high inputShort-circuit in sensor-related
circuitsON