Mazda CX-5 Service & Repair Manual: 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.

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:

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.