Infiniti EX35. Manual - part 913

HAC-48

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

AIR MIX DOOR CONTROL SYSTEM

Door Motor Circuit

Air Mix Door Control Specification

When ignition switch is ON, unified meter and A/C amp. continuously
and automatically controls temperatures regardless of air conditioner
operational condition. When setting a target temperature with tem-
perature control dial, unified meter and A/C amp. corrects the set
temperature and decides a target air mix door opening angle. Unified
meter and A/C amp. controls air mix door according to the target air
mix door opening angle and current air mix door opening angle for
keeping an optimum air mix door opening angle. When a tempera-
ture is set at 18

°

C (60

°

F), air mix door is fixed at full cold, and when

a temperature is set at 32

°

C (90

°

F), it is set at full hot.

WITH LEFT AND RIGHT VENTILATION TEMPERATURE SEPARATELY CON-
TROL SYSTEM

WITH LEFT AND RIGHT VENTILATION TEMPERATURE SEPARATELY CONTROL 
SYSTEM : System Diagram

INFOID:0000000003545593

WITH LEFT AND RIGHT VENTILATION TEMPERATURE SEPARATELY CONTROL 

JSIIA0775GB

RJIA1782E

JSIIA0776GB

AIR MIX DOOR CONTROL SYSTEM

HAC-49

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

C

D

E

F

G

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J

K

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A

B

HAC

N

O

P

SYSTEM : System Description

INFOID:0000000003545594

The air mix doors are automatically controlled so that in-vehicle temperature is maintained at a predetermined
value by the temperature setting, ambient temperature, in-vehicle temperature and amount of sunload.

SYSTEM OPERATION

• The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp.

sends air mix doors, mode door and intake door opening angle data to the air mix door motor LCUs, mode
door motor LCU and intake door motor LCU.

• The air mix door motors, mode door motor and intake door motor read their respective signals according to

the address signal. Opening angle indication signals received from the unified meter and A/C amp. and each
of the motor position sensors are compared by the LCUs in each door motor with the existing decision and
opening angles. Subsequently, HOT/COLD, DEF/VENT and FRE/REC operation is selected. The new
selection data are returned to the unified meter and A/C amp.

Door Motor Circuit

Air Mix Door Control Specification

When ignition switch is ON, unified meter and A/C amp. continuously
and automatically controls temperatures regardless of air conditioner
operational condition. When setting a target temperature with tem-
perature control dial, unified meter and A/C amp. corrects the set
temperature and decides a target air mix door opening angle. Unified
meter and A/C amp. controls air mix door according to the target air
mix door opening angle and current air mix door opening angle for
keeping an optimum air mix door opening angle. When a tempera-
ture is set at 18

°

C (60

°

F), air mix door is fixed at full cold, and when

a temperature is set at 32

°

C (90

°

F), it is set at full hot.

JSIIA0880GB

RJIA1782E

HAC-50

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

INTAKE DOOR CONTROL SYSTEM

INTAKE DOOR CONTROL SYSTEM

System Diagram

INFOID:0000000003545595

System Description

INFOID:0000000003545596

The intake doors are automatically controlled by the temperature setting, ambient temperature, in-vehicle tem-
perature, intake temperature, amount of sunload and ON/OFF operation of the compressor.

SYSTEM OPERATION

The intake door control judges intake door position based on the ambient temperature, the intake air tempera-
ture and the in-vehicle temperature. When shifting mode position D/F, when the DEF or OFF switches are
pressed, or when A/C switch is OFF, the unified meter and A/C amp. sets the intake door at the FRE position.

Door Motor Circuit

Intake Door Control Specification

JSIIA0133GB

JSIIA0880GB

INTAKE DOOR CONTROL SYSTEM

HAC-51

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

C

D

E

F

G

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B

HAC

N

O

P

Intake door position is basically fixed at FRE when FRE indicators of
DEF switch and intake switch turn ON, and fixed at REC when REC
indicator of intake switch turns ON.
Intake door automatic control selects FRE, 20 - 80%FRE, or REC
depending on a target air mix door opening angle, based on in-vehi-
cle temperature, ambient temperature, and sunload.

RJIA4067E