Mazda 6. Manual - part 87

 

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Mazda 6. Manual - part 87

 

 

CONTROL SYSTEM 

U–21

U

Outline of Control System

In the full-auto air conditioner system, the climate control unit carries out five basic types of controls based on 
signals from various sensors and control signals from the climate control unit. The climate control unit also has 
three supplementary functions.

Basic control

Control description

Correction

Airflow temperature control

Airflow temperature automatic 
control

Air intake correction

A/C correction

MAX HOT and MAX COLD correction

Coolant temperature correction

Fail-safe function

Airflow volume control

Airflow volume automatic control

Coolant temperature correction (warm-up correction)

Mild start correction

MAX HOT and MAX COLD correction

Windshield mist prevention correction

Start compensation correction

Defroster correction

Fail-safe function

Airflow volume manual control

Defroster correction

Fail-safe function

Airflow mode control

Airflow mode automatic control

Ambient temperature correction (European (L.H.D. 
U.K.) specs.)

Coolant temperature correction

Fail-safe function

Airflow mode manual control

Fail-safe function

Air intake control

Air intake automatic control

MAX COLD correction

Defroster correction

Ambient temperature correction

A/C OFF correction

Air intake manual control

Defroster correction

A/C compressor control

A/C compressor automatic control

Defroster correction

Ambient temperature correction

Windshield mist prevention correction

MAX COLD correction

A/C compressor manual control

Defroster correction

Ambient temperature correction

Windshield mist prevention correction

Supplementary function

Sensor fail-safe function

Sensor signal delay function

On-board diagnostic function

U–22

CONTROL SYSTEM 

Control Transition
Air mix, airflow volume control

( ) : GCC specs.

*1

: Setting temperature fluctuates up or down in increments of 0.5, within the range of 15.0 to 29.0 (European 

(L.H.D. U.K.) specs.) or 18.0 to 32.0 (GCC specs.). When the fan is OFF, the setting temperature can be 
adjusted in the range of 

±

1.0.

*2

: Goes up to the closest manual voltage to auto voltage or defroster correction voltage.

*3

: Goes down to the closest manual voltage to auto voltage or defroster correction voltage.

*4

: Coolant temperature correction takes precedence.

*5

: Returns to condition prior to defroster operation. However, if it is off prior to defroster operation, it switches to 

automatic control.

Airflow mode control, air intake control, A/C compressor control

Operation switch

Air mix control

Airflow volume control

Control before 

switched

Control before switched

Automatic 

control

Automatic control

Defroster 

correction

Manual control

OF

F

1

2

3

4

5

6

7

OFF switch

AUTO

OFF

OFF

OFF

AUTO switch

AUTO

AUTO

AUTO

AUTO

Fan switch

+

AUTO

MANUAL

*2

MANUAL

*2

1

2

3

4

5

6

7

7

AUTO

MANUAL

*3

MANUAL

*3

1

1

1

2

3

4

5

6

MODE switch

AUTO

AUTO

*5

No change

DEFROSTER switch

AUTO

Defroster correction

*5

Defroster correction

A/C switch

AUTO

AUTO

No change

No change

REC/FRESH switch

AUTO

AUTO

No change

No change

Temperatur
e setting 
dial

*1

15.0 (18.0)

MAX COLD

MAX HI

MAX HI

No change

15.5—28.5
(18.5—
31.5)

AUTO

AUTO

No change

No change

29.0 (32.0)

MAX HOT

AUTO HI

*4

AUTO HI

No change

Operation switch

Airflow mode control

Air intake control

A/C compressor control

Control before switched

Control before switched

Control before switched

Automatic 

control

Manual 
control

Automatic 

control

Manual 
control

Automatic 

control

Manual 
control

OFF switch

Condition 

before OFF 

switch ON

*2

No change

*2

Condition 

before OFF 

switch ON

*2

No change

*2

OFF

OFF

AUTO switch

AUTO

AUTO

AUTO

AUTO

AUTO

AUTO

Fan switch

+

AUTO

No change

AUTO

No change

AUTO

No change

AUTO

No change

AUTO

No change

AUTO

No change

MODE switch

VENT

BI-LEVEL

BI-LEVEL

HEAT

HEAT

HEAT/DEF

HEAT/DEF

VENT

DEFROSTER

HEAT

VENT

BI-LEVEL

BI-LEVEL

HEAT

HEAT

HEAT/DEF

HEAT/DEF

VENT

DEFROSTER

HEAT

AUTO

No change

*2

AUTO

No change

*3

DEFROSTER switch

DEFROSTER

*2

DEFROSTER

*2

DEFROSTER 

correction

*2

DEFROSTER 

correction

*2

DEFROSTER 

correction

*3

DEFROSTER 

correction

*3

A/C switch

AUTO

No change

AUTO

No change

A/C

ECO

ECO

A/C

OFF

A/C

*4

A/C

ECO

ECO

A/C

OFF

A/C

*4

REC/FRESH switch

AUTO

No change

FRESH

REC

REC

FRESH

FRESH

REC

REC

FRESH

AUTO

No change

CONTROL SYSTEM 

U–23

U

( ) : GCC specs.

*1

: Setting temperature fluctuates up or down in increments of 0.5, within the range of 15.0 to 29.0 (European 

(L.H.D. U.K.) specs.) or 18.0 to 32.0 (GCC specs.). When the fan is OFF, the setting temperature can be 
adjusted in the range of 

±

1.0.

*2

: If operated when in defroster correction, it returns to the condition prior to defroster operation.

*3

: Ambient temperature correction takes precedence. If operated when in defroster correction, it returns to the 

condition prior to defroster operation. However, if it is off prior to defroster operation, it switches to automatic 
control.

*4

: Ambient temperature correction takes precedence. When the fan is OFF, the A/C is fixed at off.

End Of Sie

AIRFLOW TEMPERATURE CONTROL

A6E854001044T04

Airflow temperature is controlled by the air mix actuator so that the passenger compartment temperature 
remains at the target temperature (control computation value T1).

Control computation value T1 is the target temperature in the cabin set by the climate control unit based on 
differences among set temperature, input temperature from the sensors, and sunlight intensity.

.

Temperatur
e setting 
dial

*1

15.0 (18.0)

AUTO

No change

AUTO

No change

AUTO

No change

15.5—28.5
(18.5—
31.5)

29.0 (32.0)

Operation switch

Airflow mode control

Air intake control

A/C compressor control

Control before switched

Control before switched

Control before switched

Automatic 

control

Manual 

control

Automatic 

control

Manual 
control

Automatic 

control

Manual 
control

A6E8540T041

1

Set temperature

2

Sunlight intensity

3

Ambient temperature

4

Evaporator temperature

5

Cabin temperature

6

Airflow  mode

7

Air intake mode

8

A/C compressor control condition

9

Signals

10

Climate control unit

11

Output

12

Feedback

13

Air mix actuator

14

Operation

15

Air mix doors

16

Airflow temperature changes

U–24

CONTROL SYSTEM 

Airflow Temperature Automatic Control

Based on the set temperature and sunlight intensity, the climate control unit calculates the air mix actuator 
opening angle characteristic. The higher the sunlight intensity, the lower the air mix actuator opening angle 
characteristic.

The climate control unit compares the air mix actuator opening angle characteristic, the present ambient 
temperature and target temperature (control computation value T1) and determines a basic angle of opening 
for the air mix actuator.

.

Correction
Air intake correction

When the A/C mode is off, the air mix actuator opening angle is corrected to prevent airflow temperature rise 
when the air intake mode is switched from fresh air to recirculated air. In addition, this correction retards the air 
mix actuator operation to prevent a sudden drop in airflow temperature.

.

A6E8540T042

1

Air mix actuator basic opening

2

MAX HOT

3

MAX COLD

4

Ambient temperature

5

Low

6

High

7

When the sunlight intensity is low

8

When the sunlight intensity is high

9

Air mix actuator opening angle characteristic (A/C 
off mode)

10

Air mix actuator opening angle characteristic (A/C 
on mode)

A6E8540T001

1

Air mix actuator opening angle delay

2

Air  intake  mode

3

Air mix actuator opening angle correction amount

4

HOT

5

COLD

6

FRESH

7

RECIRCULATE

8

Time

 

 

 

 

 

 

 

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