Infiniti G35 (V35) Sedan. Manual - part 766

 

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Infiniti G35 (V35) Sedan. Manual - part 766

 

 

HAC-36

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

AUTOMATIC AIR CONDITIONER SYSTEM

SWITCHES AND THEIR CONTROL FUNCTION

AIR CONDITIONER LAN CONTROL SYSTEM

The LAN (Local Area Network) system consists of unified meter and A/C amp., mode door motor, air mix door
motors and intake door motor.

JSIIA0078GB

JSIIA0080GB

AUTOMATIC AIR CONDITIONER SYSTEM

HAC-37

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

C

D

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A configuration of these components is shown in the figure below.

SYSTEM CONSTRUCTION

A small network is constructed between the unified meter and A/C amp., mode door motor, air mix door
motors and intake door motor. The unified meter and A/C amp. and motors are connected by data transmis-
sion lines and motor power supply lines. The LAN network is built through the ground circuits of each door
motor.
Addresses, motor opening angle signals, motor stop signals and error checking messages are all transmitted
through the data transmission lines connecting the unified meter and A/C amp. and each door motor.
The following functions are contained in LCUs built into the mode door motor, the air mix door motors and the
intake door motor.
• Address
• Motor opening angle signals
• Data transmission
• Motor stop and drive decision
• Opening angle sensor (PBR function)
• Comparison
• Decision (Unified meter and A/C amp. indicated value and motor opening angle comparison)

Operation

The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp.
sends mode door, air mix door and intake door opening angle data to the mode door motor LCU, air mix door
motor LCUs and intake door motor LCU.
The mode door motor, air mix door motors 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 is compared by the LCUs in each door motor with the existing decision and open-
ing angles. Subsequently, HOT/COLD, DEF/VENT and FRE/REC operation is selected. The new selection
data is returned to the unified meter and A/C amp.

Transmission Data and Transmission Order

Unified meter and A/C amp. data is transmitted consecutively to each of the doors motor following the form
shown in the figure below.

SJIA1609E

RJIA1747E

RJIA1748E

HAC-38

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

AUTOMATIC AIR CONDITIONER SYSTEM

START:

• Initial compulsory signal is sent to each of the door motors.

ADDRESS:

• Data sent from the unified meter and A/C amp. are selected according to data-based decisions made by the

mode door motor, air mix door motors and intake door motor.

• If the addresses are identical, the opening angle data and error check signals are received by the door motor

LCUs. The LCUs then make the appropriate error decision. If the opening angle data have no error, door
control begins.

• If an error exists, the received data are rejected and corrected data received. Finally, door control is based

upon the corrected opening angle data.

OPENING ANGLE:

• Data that shows the indicated door opening angle of each door motor.

ERROR CHECK:

• In this procedure, transmitted and received data is checked for errors. Error data are then compiled. The

error check prevents corrupted data from being used by the mode door motor, the air mix door motors and
the intake door motor. Error data can be related to the following symptoms.

- Malfunction of electrical frequency
- Poor electrical connections
- Signal leakage from transmission lines
- Signal level fluctuation

STOP SIGNAL:

• At the end of each transmission, a stop operation, in-operation, or internal malfunction message is delivered

to the unified meter and A/C amp. This completes one data transmission and control cycle.

AIR MIX DOOR CONTROL (AUTOMATIC TEMPERATURE CONTROL)

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.

FAN SPEED CONTROL

Blower speed is automatically controlled by the temperature setting, ambient temperature, in-vehicle tempera-
ture, intake temperature, amount of sunload and air mix door position.
With pressing AUTO switch, the blower motor starts to gradually increase air flow volume.
When engine coolant temperature is low, the blower motor operation is delayed to prevent cool air from flow-
ing.

INTAKE DOOR CONTROL

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.

MODE DOOR CONTROL

The mode door is automatically controlled by the temperature setting, ambient temperature, in-vehicle temper-
ature, intake temperature and amount of sunload.

RJIA1749E

AUTOMATIC AIR CONDITIONER SYSTEM

HAC-39

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

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MAGNET CLUTCH CONTROL

When A/C switch, AUTO switch, DEF switch is pressed or when shifting mode position D/F, unified meter and
A/C amp. transmits compressor ON signal to ECM, via CAN communication.
ECM judges whether compressor can be turned ON, based on each sensor status (refrigerant-pressure sen-
sor signal, throttle angle, etc.). If it judges compressor can be turned ON, it sends compressor ON signal to
IPDM E/R, via CAN communication.
Upon receipt of compressor ON signal from ECM, IPDM E/R turns air conditioner relay ON to operate com-
pressor.
When sending compressor ON signal to IPDM E/R via CAN communication line, ECM simultaneously sends
compressor feedback signal to ECM via CAN communication line.
ECM sends compressor feedback signal to unified meter and A/C amp., then, uses input compressor feed-
back signal to control air inlet.

WITH LEFT AND RIGHT VENTILATION TEMPERATURE SEPARATELY CONTROL 
SYSTEM : Component Part Location

INFOID:0000000000959914

ENGINE COMPARTMENT

JSIIA0148GB

 

 

 

 

 

 

 

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