#
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