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Nissan Pathfinder. Manual - part 689

COMPONENT PARTS

HAC-17

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONING]

HAC

Rear blower motor 2

The rear blower motor-2 varies the speed at which the air flows through the ventilation sys-
tem.

Rear blower motor relay

The rear blower motor relay controls the flow of current to the rear blower motor. The relay
is connected directly to ground, and is controlled by the BCM.

Rear shut-off door motor

The rear shut-off door controls the conditioned air through the ventilation system. The rear
shut-off door motor receives position commands from the A/C auto amp. and reports actual
door position back via an LCU (Local Control Unit) installed inside the motor. Commands
and responses are sent across the LIN (Local Interconnect Network) to each motor simulta-
neously, with each motor having its own unique address, thereby only responding to re-
quests sent to its specific address. The LCU reads the door position from a Position
Balanced Resistor (PBR), also part of the motor, and returns that information to the front air
control. The LCU switches the polarity of the circuits connected to the DC motor to drive the
motor forward or backward as requested by the A/C auto amp. The mode door has 2 expect-
ed positions and therefore will set a DTC if the expected position is not reported back to the
A/C auto amp.

Component

Description

HAC-18

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONING]

SYSTEM

SYSTEM

FRONT AUTOMATIC AIR CONDITIONING SYSTEM
FRONT AUTOMATIC AIR CONDITIONING SYSTEM : System Diagram

INFOID:0000000009176781

FRONT AUTOMATIC AIR CONDITIONING SYSTEM : System Description

INFOID:0000000009176782

• Front automatic air conditioning system is controlled by each function of A/C auto amp., ECM, IPDM E/R

and BCM.

Control by A/C auto amp.

HAC-20, "FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Air Flow Control"

HAC-21, "FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Air Inlet Control"

ALIIA0685GB

SYSTEM

HAC-19

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONING]

HAC

HAC-21, "FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Air Outlet Control"

HAC-22, "FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Compressor Control"

HAC-23, "FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Door Control"

HAC-25, "FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Temperature Control"

HAC-19, "FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Intelligent Key Interlock Function"

- Correction for input value of each sensor

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 the passenger may feel. Correction is applied to the target temperature that is set using tem-

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

In-vehicle sensor [in-vehicle temperature (front side) correction]

• Passenger room temperature (front side) detected by in-vehicle sensor is corrected for each front air condi-

tioning control (driver side and passenger side).

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 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.

Control by ECM

- Cooling fan control

Refer to

EC-38, "COOLING FAN CONTROL : System Description"

- Air conditioning cut control

Refer to

EC-36, "AIR CONDITIONING CUT CONTROL : System Description"

Control by IPDM E/R

- Relay control

Refer to

PCS-5, "RELAY CONTROL SYSTEM : System Description"

- Cooling fan control

Refer to

EC-38, "COOLING FAN CONTROL : System Description"

Control by BCM

- Intelligent Key interlock function

Refer to

HAC-19, "FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Intelligent Key Interlock Function"

- Relay control

Refer to

BCS-7, "BODY CONTROL SYSTEM : System Description"

• Vehicles with base audio system, the A/C switch assembly transmits the commands for front automatic air

conditioning system operation to the A/C auto amp. via communication line. A/C auto amp. transmits each

indication information to the A/C display unit via communication line. A/C display unit displays each indica-

tion information that is received.

• Vehicles without base audio system, the A/C and AV switch assembly transmits the commands for front

automatic air conditioning system operation to the 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 indi-

cation information to AV control unit via CAN communication. AV control unit displays each indication infor-

mation that is received.

FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Intelligent Key Interlock Func-
tion

INFOID:0000000009176783

DESCRIPTION

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

Intelligent Key. 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.

HAC-20

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONING]

SYSTEM

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

inlet status, and others) of 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 air conditioning system according to

setting information of Key ID that is received.

NOTE:

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

FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Air Flow Control

INFOID:0000000009176784

DESCRIPTION

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

flow is increased, duty ratio of front 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 consist of starting fan speed control,

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

door motor operation

AUTOMATIC AIR FLOW CONTROL

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

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

so that air flow matches the target air flow.

• When air outlet is VENT or B/L, the minimum air flow is changed

depending on sunload.

STARTING AIR FLOW CONTROL

Operation

Conditions

A/C and AV switch assembly

AUTO switch (ON / OFF)

Setting temperature (Setting value)

Air flow (Setting value)

Air inlet (FRE / REC)

Air outlet (VENT / B/L / FOOT / D/F / DEF)

“Climate” menu screen

“A/C” (ON / OFF)

“DUAL” (ON / OFF)

JMIIA0735GB

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