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Nissan Pathfinder. Manual - part 691

SYSTEM

HAC-25

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONING]

HAC

FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Temperature Control

INFOID:0000000009176789

• When ignition switch is in the ON position, A/C auto amp. always

automatically controls temperature regardless of front air condi-

tioning operational state.

• A/C auto amp. calculates the target air mix door (front) opening

angle depending on set temperature, in-vehicle temperature, ambi-

ent temperature, and sunload.

• Air mix door (front) is controlled depending on the comparison of

current air mix door (front) opening angle and target air mix door

(front) opening angle.

• Regardless of in-vehicle temperature, ambient temperature, and

sunload, air mix door (front) is fixed at the fully cold position when

set temperature is 18.0

°C (60°F), and at the fully hot position when

set temperature is 32.0

°C (90°F).

FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Fail-safe

INFOID:0000000009176790

FAIL-SAFE FUNCTION

If a communication error exists between the A/C auto amp., and the AV control unit and preset switch for 30

seconds or longer, air conditioning is controlled under the following conditions:

When ambient temperature is less than 3

°C (37°F) and engine coolant temperature is less than 56°C (133°F)

When ambient temperature is 3

°C (37°F) or more, or engine coolant temperature is 56°C (133°F) or more

REAR AUTOMATIC AIR CONDITIONING SYSTEM

Discharge air flow

MODE/DEF set

position

Condition

Air outlet/distribution

Ventilator

Foot

Defroster

Center

Side

Front

Rear

DUAL switch:
OFF

50%

—

26%

30%

14%

—

14%

40%

16.5%

29.5%

—

14%

35%

16%

35%

—

12%

—

88%

JMIIA0731GB

Compressor

: ON

Air outlet

: DEF

Air inlet

: FRE (Fresh air intake)

Blower fan speed

: AUTO

Set temperature

: Setting before communication error occurs

Compressor

: ON

Air outlet

: AUTO

Air inlet

: 20% FRE (20% fresh air intake)

Blower fan speed

: AUTO

Set temperature

: Setting before communication error occurs

HAC-26

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONING]

SYSTEM

REAR AUTOMATIC AIR CONDITIONING SYSTEM : System Diagram

INFOID:0000000009176791

REAR AUTOMATIC AIR CONDITIONING SYSTEM : System Description

INFOID:0000000009176792

• Rear automatic air conditioning system is controlled by each function of A/C auto amp.

Control by A/C auto amp.

HAC-28, "REAR AUTOMATIC AIR CONDITIONING SYSTEM : Air Flow Control"

HAC-29, "REAR AUTOMATIC AIR CONDITIONING SYSTEM : Air Outlet Control"

HAC-29, "REAR AUTOMATIC AIR CONDITIONING SYSTEM : Door Control"

HAC-30, "REAR AUTOMATIC AIR CONDITIONING SYSTEM : Temperature Control"

HAC-27, "REAR AUTOMATIC AIR CONDITIONING SYSTEM : Intelligent Key Interlock Function"

- Correction for input value of each sensor

ALIIA0686GB

SYSTEM

HAC-27

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONING]

HAC

Ambient sensor (setting temperature correction)

• A/C auto amp. controls passenger room temperature so that the optimum level always matches the temper-

ature level that passenger may feel. Correction is applied to the target temperature that is set using temper-

ature control dial, according to ambient temperature detected by ambient sensor.

Intake sensor (intake temperature correction)

• A/C auto amp. performs correction to change recognition intake temperature of A/C auto amp. quickly when

difference is large between recognition intake temperature and intake temperature detected by intake tem-

perature sensor. The correction is performed to change recognition intake temperature slowly when differ-

ence is small.

Sunload sensor (sunload amount correction)

• Sunload amount detected by sunload sensor is corrected for each rear automatic air conditioning control.

• A/C auto amp. performs correction to change recognition sunload amount of A/C auto amp. slowly when

sunload amount changes quickly, for example when entering or exiting a tunnel.

Operation by front controller (with base audio system)

- Front A/C control (A/C switch assembly) transmits the commands for rear automatic air conditioning system

operation to A/C auto amp. via communication line, the A/C auto amp. transmits each indication information

to A/C display unit via communication line. A/C display unit displays each indication information that is

received.

Operation by front controller (except base audio system)

- Front A/C control (A/C and AV switch assembly) transmits the commands for rear automatic air conditioning

system operation to AV control unit via communication line, then AV control unit transmits the commands to

A/C auto amp. via CAN communication. A/C auto amp. transmits each indication information to AV control

unit via CAN communication. AV control unit displays each indication information that is received.

Operation by rear controller

- Rear air control transmits the commands for rear automatic air conditioning system operation to A/C auto

amp. via communication line.

REAR AUTOMATIC AIR CONDITIONING SYSTEM : Intelligent Key Interlock Function

INFOID:0000000009176793

DESCRIPTION

• Setting value of rear air conditioning system when ignition switch is previously OFF can be memorized for

each Intelligent Key. Rear air conditioning system is automatically operated by the setting value.

NOTE:

Setting value can be memorized for up to 3 Intelligent Keys.

• Interlock items are as per the following table.

Operation Description

Memory

1. Unlock door using Intelligent Key or driver door request switch.

2. BCM transmits Key ID signal to A/C auto amp. via CAN communication line.

3. When ignition switch turns OFF, A/C auto amp. memorizes setting information (setting temperature, air

outlet status, and others) of rear air conditioning system to memory for each Key ID.

Readout

1. Unlock door using Intelligent Key or driver door request switch.

2. BCM transmits Key ID signal to A/C auto amp. via CAN communication line.

3. When ignition switch turns ON, A/C auto amp. operates automatically rear air conditioning system accord-

ing to setting information of Key ID that is received.

NOTE:

Operation

Conditions

A/C and AV switch assembly / Rear
air control

AUTO switch (ON/OFF)

Setting temperature (Setting value)

Air flow (Setting value)

Air outlet (VENT / FOOT)

HAC-28

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONING]

SYSTEM

When Intelligent Key interlock function operates, “Connection with the key has been done.” is displayed.

REAR AUTOMATIC AIR CONDITIONING SYSTEM : Air Flow Control

INFOID:0000000009176794

DESCRIPTION

• A/C auto amp. changes duty ratio of rear blower motor drive signal and controls air flow continuously. When

air flow is increased, duty ratio of rear blower motor control signal gradually increases to prevent a sudden

increase in air flow.

• In addition to manual control and automatic control, air flow control is composed of starting fan speed con-

trol, low coolant temperature starting control, high in-vehicle temperature starting control and fan speed con-

trol at door motor operation

AUTOMATIC AIR FLOW CONTROL

• A/C auto amp. decides target air flow depending on target air mix door (rear) opening angle.

• A/C auto amp. changes duty ratio of rear blower motor control signal and controls the air flow continuously

so that air flow matches to target air flow.

• When air outlet is VENT, the minimum air flow is changed depend-

ing on sunload.

STARTING AIR FLOW CONTROL

• When rear blower motor is activated, A/C auto amp. gradually

increases duty ratio of rear blower motor control signal to prevent a

sudden increase in discharge air flow.

• It takes approximately 8 seconds for air flow to reach HI from LOW.

LOW COOLANT TEMPERATURE STARTING CONTROL

If the engine coolant temperature is 56

°C (133°F) or less, to prevent

a cold discharged air flow, A/C auto amp. suspends rear blower

motor activation for the maximum 150 seconds depending on target

air mix door (rear) opening angle. After this, rear blower motor con-

trol signal is increased gradually, and rear blower motor is activated.

HIGH IN-VEHICLE TEMPERATURE STARTING CONTROL

When front evaporator fin temperature is high [intake sensor value is 35

°C (95°F) or more], to prevent a hot

discharged air flow, A/C auto amp. suspends rear blower motor activation for approximately 3 seconds so that

rear evaporator is cooled by refrigerant.

FAN SPEED CONTROL AT DOOR MOTOR OPERATION

JMIIA0738GB

JMIIA0739GB

JMIIA0740GB

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