Control System

AUTOMATIC AIR CONDITIONER SYSTEM

Control System Diagram

CONTROL SYSTEM
The control system consists of input sensors, switches, the front air control (microcomputer) and outputs.
The relationship of these components is shown in the figure below:






Control System Description

CONTROL OPERATION

Front air control






AUTO SWITCH
- The compressor, intake door, air mix doors, outlet doors and blower speed are automatically controlled so that the in-vehicle temperature will reach, and be maintained at the set temperature selected by the operator.
- When pressing AUTO switch, air inlet, air outlet, blower speed, and discharge air temperature are automatically controlled.

TEMPERATURE CONTROL DIAL (DRIVER)
Increases or decreases the set temperature.

TEMPERATURE CONTROL DIAL (PASSENGER)
Increases or decreases the set temperature.

RECIRCULATION SWITCH






DEFROSTER SWITCH






REAR WINDOW DEFOGGER SWITCH (CREW CAB)
When switch is ON, rear window and door mirrors are defogged.

OFF SWITCH
The compressor and blower are OFF, the intake doors are set to the outside air position, and the air outlet doors are set to the foot (75% foot and 25% defrost) position.

BLOWER CONTROL DIAL
The blower speed is manually controlled with this dial.

A/C SWITCH
The compressor is ON or OFF.
(Pressing the A/C switch when the AUTO switch is ON will turn off the A/C switch and compressor.)

MODE SWITCHES
Controls the air discharge outlets.

DUAL SWITCH
- When the DUAL switch indicator is illuminated, the driver and passenger temperature can each be set independently.
- When the DUAL switch indicator is not illuminated, the driver temperature setting is applied to both sides.

MAGNET CLUTCH CONTROL






When A/C switch or DEF switch is pressed, front air control inputs compressor ON signal to BCM.
BCM sends compressor ON signal to ECM and front air control, via CAN communication line.

ECM judges whether compressor can be turned ON, based on each sensor status (refrigerant pressure sensor signal, throttle angle sensor, etc.). If it judges compressor can be turned ON, it sends compressor ON signal to IPDM E/R, via CAN communication line.
Upon receipt of compressor ON signal from ECM, IPDM E/R turns air conditioner relay ON to operate compressor.

Discharge Air Flow






Switches And Their Control Function