A/C COMPRESSOR CONTROL [FULL-AUTO AIR CONDITIONER]

id0740a1108000

Purpose

• The A/C compressor control switches the A/C compressor on/off according to the vehicle environment.

Function

• The A/C compressor control turns the A/C compressor on/off based on the climate control unit operation and signals from each sensor.

• The A/C compressor control has automatic and manual controls.

• The A/C compressor automatic control performs the following correction:

― Defroster correction

A/C compressor automatic control

• The climate control unit determines the A/C ON/OFF mode based on the ambient temperature.

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• The climate control unit determines the A/C signal on/off according to the air conditioner operation such as A/C ON mode (A/C switch ON) or AUTO mode (AUTO switch ON).

• In A/C ON mode, the A/C signal (magnetic clutch) on/off is determined based on the ambient temperature and the temperature of the air passing through the evaporator.

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• In AUTO mode, the A/C signal (magnetic clutch) on/off is determined based on the ambient temperature calculation value and the temperature of the air passing through the evaporator.

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• The ambient temperature calculation value is calculated based on the ambient temperature, set temperature, cabin temperature, and sunlight intensity.

• When the ambient temperature is low, the A/C signal (magnetic clutch) OFF temperature is set lower to prevent window fogging.

A/C compressor manual control

• The climate control unit switches the A/C ON/OFF mode and ECO mode according to the A/C switch operation.

A/C mode

Operation condition

A/C ON mode (A/C display)

A/C mode (A/C display)

Fixed in A/C mode.

A/C OFF mode (No display)

Fixed in A/C OFF mode.

A/C ON mode (ECO display)

ECO mode (ECO display)

Fixed in ECO mode.

A/C mode	Operation condition
A/C ON mode (A/C display)	A/C mode (A/C display)	Fixed in A/C mode.
A/C OFF mode (No display)	Fixed in A/C OFF mode.
A/C ON mode (ECO display)	ECO mode (ECO display)	Fixed in ECO mode.

Correction

Defroster correction

• When the defroster switch is turned on, the system is switched to A/C ON mode to improve defogging.

Construction

• The A/C compressor control consists of the parts indicated in the following table:

Input device

Control part

Output device

•  A/C switch (climate control unit)

•  Mode switch (climate control unit)

•  Temperature setting dial (climate control unit)

•  Refrigerant pressure sensor

•  Solar radiation sensor

•  Cabin temperature sensor

•  Ambient temperature sensor

•  Evaporator temperature sensor

•  Climate control unit

•  PCM

•  Instrument cluster

•  A/C relay

•  Magnetic clutch (A/C compressor)

Input device	Control part	Output device
• A/C switch (climate control unit) • Mode switch (climate control unit) • Temperature setting dial (climate control unit) • Refrigerant pressure sensor • Solar radiation sensor • Cabin temperature sensor • Ambient temperature sensor • Evaporator temperature sensor	• Climate control unit • PCM • Instrument cluster	• A/C relay • Magnetic clutch (A/C compressor)

Operation

1. The climate control determines the A/C ON/OFF based on the operations of each switch/dial and signals from each sensor which changes according to the vehicle environment.

2. The climate control unit sends the A/C signal to the PCM according to the result of the A/C ON/OFF determination and corrections.

3. When the PCM turns the A/C relay on based on the A/C signal, the magnetic clutch of the A/C compressor turns on.

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