FULL-AUTO AIR CONDITIONER FUNCTION

id074000100600

Block Diagram

• The control system consists of input components (sensors), output components (actuators, magnetic clutch, power MOS FET, and other parts), and a control device (climate control unit).

.

1
Ambient temperature sensor
2
Cabin temperature sensor
3
Water temperature sensor
4
Evaporator temperature sensor
5
Solar radiation sensor
6
Climate control unit
7
Airflow temperature control
8
Airflow volume control
9
Airflow mode control
10
Air intake control
11
A/C compressor control
12
Air mix actuator
13
Power MOS FET
14
Blower motor
15
Airflow mode actuator
16
Air intake actuator
17
Refrigerant pressure switch (HI and LO pressure)
18
Refrigerant pressure switch (middle pressure) (Triple-pressure switch)
19
A/C cut control
20
A/C relay
21
Idle speed control
22
Thermal protector
23
Magnetic clutch

Outline of Control System

• In the full-auto air conditioner system, the climate control unit carries out five basic types of controls based on signals from various sensors and control signals from the climate control unit. The climate control unit also has three supplementary functions.

Basic control

Control description

Correction

Airflow temperature control
Airflow temperature automatic control
• Air intake correction
• A/C correction
• MAX HOT and MAX COLD correction
• Coolant temperature correction
• Fail-safe function
Airflow volume control
Airflow volume automatic control
• Coolant temperature correction (warm-up correction)
• Mild start correction
• MAX HOT and MAX COLD correction
• Windshield mist prevention correction
• Start compensation correction
• Defroster correction
• Fail-safe function
Airflow volume manual control
• Defroster correction
• Fail-safe function
Airflow mode control
Airflow mode automatic control
• Ambient temperature correction (European (L.H.D. U.K.) specs.)
• Engine coolant temperature correction (Warm-up correction)
• Fail-safe function
Airflow mode manual control
• Fail-safe function
Air intake control
Air intake automatic control
• MAX COLD correction
• Defroster correction
• Ambient temperature correction
• A/C OFF correction
Air intake manual control
• Defroster correction
A/C compressor control
A/C compressor automatic control
• Defroster correction
• Ambient temperature correction
• Windshield mist prevention correction
• MAX COLD correction
A/C compressor manual control
• Defroster correction
• Ambient temperature correction
• Windshield mist prevention correction

Supplementary function

Sensor fail-safe function
Sensor signal delay function
On-board diagnostic function

Control Transition

Air mix, airflow volume control

Operation switch

Air mix control

Airflow volume control

Control before switched

Control before switched

Automatic control

Automatic control

Defroster correction

Manual control

OFF

1

2

3

4

5

6

7

OFF switch
AUTO
OFF
OFF
OFF
AUTO switch
AUTO
AUTO
AUTO
AUTO
Fan switch
+
AUTO
MANUAL*2
MANUAL*2
1
2
3
4
5
6
7
7
-
AUTO
MANUAL*3
MANUAL*3
1
1
1
2
3
4
5
6
MODE switch
AUTO
AUTO

*5

No change
DEFROSTER switch
AUTO
Defroster correction

*5

Defroster correction
A/C switch
AUTO
AUTO
No change
No change
REC/FRESH switch
AUTO
AUTO
No change
No change
Temperature setting dial*1
15.0 (18.0)
MAX COLD
MAX HI
MAX HI
No change
15.5-28.5
(18.5-31.5)
AUTO
AUTO
No change
No change
29.0 (32.0)
MAX HOT
AUTO HI*4
AUTO HI
No change

( ) :
Australian, General (L.H.D. R.H.D.) specs.
*1 :
Setting temperature fluctuates up or down in increments of 0.5, within the range of 15.0 to 29.0 (European (L.H.D. U.K.) specs.) or 18.0 to 32.0 (Australian, General (L.H.D. R.H.D.) specs.). When the fan is OFF, the setting temperature can be adjusted in the range of ±1.0.
*2 :
Goes up to the closest manual voltage to auto voltage or defroster correction voltage.
*3 :
Goes down to the closest manual voltage to auto voltage or defroster correction voltage.
*4 :
Coolant temperature correction takes precedence.
*5 :
Returns to condition prior to defroster operation. However, if it is off prior to defroster operation, it switches to automatic control.

Airflow mode control, air intake control, A/C compressor control

Operation switch

Airflow mode control

Air intake control

A/C compressor control

Control before switched

Control before switched

Control before switched

Automatic control

Manual control

Automatic control

Manual control

Automatic control

Manual control

OFF switch
Condition before OFF switch ON*2
No change*2
Condition before OFF switch ON*2
No change*2
OFF
OFF
AUTO switch
AUTO
AUTO
AUTO
AUTO
AUTO
AUTO
Fan switch
+
AUTO
No change
AUTO
No change
AUTO
No change
-
AUTO
No change
AUTO
No change
AUTO
No change
MODE switch
VENT→
BI-LEVEL
BI-LEVEL→
HEAT
HEAT→
HEAT/DEF
HEAT/DEF→
VENT
DEFROSTER
→HEAT
VENT→
BI-LEVEL
BI-LEVEL→
HEAT
HEAT→
HEAT/DEF
HEAT/DEF→
VENT
DEFROSTER
→HEAT
AUTO
No change*2
AUTO
No change*3
DEFROSTER switch
DEFROSTER*2
DEFROSTER*2
DEFROSTER correction*2
DEFROSTER correction*2
DEFROSTER correction*3
DEFROSTER correction*3
A/C switch
AUTO
No change
AUTO
No change
A/C→ECO
ECO→A/C
OFF→A/C*4
A/C→ECO
ECO→A/C
OFF→A/C*4
REC/FRESH switch
AUTO
No change
FRESH→REC
REC→FRESH
FRESH→REC
REC→FRESH
AUTO
No change
Temperature setting dial*1
15.0 (18.0)
AUTO
No change
AUTO
No change
AUTO
No change
15.5-28.5
(18.5-31.5)
29.0 (32.0)

( ) :
Australian, General (L.H.D. R.H.D.) specs.
*1 :
Setting temperature fluctuates up or down in increments of 0.5, within the range of 15.0 to 29.0 (European (L.H.D. U.K.) specs.) or 18.0 to 32.0 (Australian, General (L.H.D. R.H.D.) specs.). When the fan is OFF, the setting temperature can be adjusted in the range of ±1.0.
*2 :
If operated when in defroster correction, it returns to the condition prior to defroster operation.
*3 :
Ambient temperature correction takes precedence. If operated when in defroster correction, it returns to the condition prior to defroster operation. However, if it is off prior to defroster operation, it switches to automatic control.
*4 :
Ambient temperature correction takes precedence. When the fan is OFF, the A/C is fixed at off.