Infiniti EX35. Manual - part 912

HAC-44

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

CAN COMMUNICATION SYSTEM

CAN COMMUNICATION SYSTEM

System Description

INFOID:0000000003545584

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only. For details, refer to 

LAN-27,

"CAN System Specification Chart"

.

MODE DOOR CONTROL SYSTEM

HAC-45

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

C

D

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F

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A

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HAC

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MODE DOOR CONTROL SYSTEM

System Diagram

INFOID:0000000003545589

System Description

INFOID:0000000003545590

The mode door is automatically controlled by the temperature setting, ambient temperature, in-vehicle temper-
ature, intake 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 door, mode door and intake door opening angle data to the air

mix door motor LCU(s), mode door motor LCU and intake door motor LCU.

• The air mix door motor(s), 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

Mode Door Control Specification

JSIIA0772GB

JSIIA0880GB

HAC-46

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

MODE DOOR CONTROL SYSTEM

Mode position can be selected manually by pressing MODE switch
or DEF switch of the preset switch. This enables to fix a mode posi-
tion. Automatic control by unified meter and A/C amp. Pressing
AUTO switch allows automatic control by unified meter and A/C
amp. During the automatic control of mode position, a mode door
position (VENT, B/L, FOOT, or D/F) is selected based on a target air
mix door opening angle and sunload depending on a temperature
calculated by unified meter and A/C amp. In addition, D/F is selected
to prevent windshield fogging only when ambient temperature is
extremely low with mode position FOOT.

RJIA1778E

AIR MIX DOOR CONTROL SYSTEM

HAC-47

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

C

D

E

F

G

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J

K

L

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A

B

HAC

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AIR MIX DOOR CONTROL SYSTEM

WITHOUT LEFT AND RIGHT VENTILATION TEMPERATURE SEPARATELY
CONTROL SYSTEM

WITHOUT LEFT AND RIGHT VENTILATION TEMPERATURE SEPARATELY CON-
TROL SYSTEM : System Diagram

INFOID:0000000003545591

WITHOUT LEFT AND RIGHT VENTILATION TEMPERATURE SEPARATELY CON-
TROL SYSTEM : System Description

INFOID:0000000003545592

The air mix door is 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.

JSIIA0774GB