MANUAL AIR CONDITIONER FUNCTION

id074000638600

Block Diagram

• The climate control unit carries out the defroster control base on signal sent from the airflow mode selector dial, and sends an operating signal to the air intake actuator.
• The center panel sends an A/C signal to the PCM via the refrigerant pressure switch based on signals sent from the A/C switch, fan switch and evaporator temperature sensor.

.

1
Evaporator temperature sensor
2
A/C switch
3
Fan switch
4
Center panel
5
A/C compressor control
6
Refrigerant pressure switch (HI and LO pressure)
7
Refrigerant pressure switch (middle pressure) (Triple-pressure type)
8
Climate control unit
9
Defroster control
10
A/C cut-off control
11
Idle air control
12
Air intake actuator
13
A/C relay
14
Thermal protector
15
Magnetic clutch

Outline of Control System

• Manual air conditioner defroster control and A/C compressor control.

Control name

Control part

Defroster control
Climate control unit
A/C compressor control
Center panel

Defroster Control

1. When the airflow mode selector dial is turned to DEFROSTER position, a wire moves the airflow mode main link, turning the airflow mode to DEFROSTER.

2. The defroster switch turns on at the same time, and the CPU sends a signal to turn the air intake mode to FRESH.

3. The air intake actuator operates and turns the air intake mode to FRESH.

.

1
Climate control unit
2
Airflow mode selector dial
3
DEFROSTER
4
Wire
5
Move
6
Airflow mode main link
7
Defroster switch
8
FRESH signal
9
Air intake actuator
10
FRESH

X: Operates
-: Does not operate

Airflow mode

Air intake mode (REC/FRESH switch pushed)

Defroster control

VENT
REC ⇔ FRESH
-
BI-LEVEL
REC ⇔ FRESH
-
HEAT
REC ⇔ FRESH
-
HEAT/DEF
REC ⇔ FRESH
-
DEFROSTER
FRESH
x

A/C Compressor Control

• The center panel sends an A/C signal to the PCM via the refrigerant pressure switch based on signals sent from the A/C switch, fan switch and evaporator temperature sensor.

.

1
Evaporator temperature sensor
2
A/C signal
3
Center panel
4
Output
5
A/C relay
6
Magnetic clutch

A/C signal on/off control

• The center panel turns the A/C signal (magnetic clutch) on and off based on the temperature of the air passing through the evaporator when the A/C and fan switches are on. This keeps the evaporator surface temperature within the specified range, preventing the evaporator from freezing while the fan switch and A/C switch are turned on.

.

1
A/C signal on/off decision
2
Evaporator temperature sensor
3
A/C signal