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

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2014 - Mazda6 - HVAC

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

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.

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.

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.

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 according to the A/C switch operation.


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