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Nissan Murano Z51 (2008 year). Manual - part 229

AUTOMATIC AIR CONDITIONER SYSTEM

HAC-139

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

HAC

SWITCHES AND THEIR CONTROL FUNCTION

AIR CONDITIONER LAN CONTROL SYSTEM

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

JPIIA0445GB

JPIIA0452GB

Revision: 2008 October

2009 Murano

HAC-140

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

AUTOMATIC AIR CONDITIONER SYSTEM

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

SYSTEM CONSTRUCTION

A small network exists between the A/C auto amp., the mode door motor, the air mix door motors, the upper
ventilator door motor and the intake door motor. The A/C auto amp. and motors are connected by data trans-
mission 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 A/C auto amp. and each door motor.
The following functions are contained in LCUs built into the mode door motor, the air mix door motors, the
upper ventilator door motor and the intake door motor.
• Address
• Motor opening angle signals
• Data transmission
• Motor stop and drive decision
• Opening angle sensor (PBR function)
• Comparison
• Decision (A/C auto amp. indicated value and motor opening angle comparison)

Operation

The A/C auto amp. receives data from each of the sensors. The A/C auto amp. sends mode door, the air mix
door and the intake door opening angle data to the mode door motor LCU, the air mix door motor LCUs, the
upper ventilator door motor LCU and the intake door motor LCU.
The mode door motor, the air mix door motors, the upper ventilator door motor and the intake door motor read
their respective signals according to the address signal. Opening angle indication signals received from the A/
C auto amp. and each of the motor position sensors is compared by the LCUs in each door motor with the
existing decision and opening angles. Next, HOT/COLD, DEF/VENT, OPEN/SHUT or FRE/REC operation is
selected. The new selection data is returned to the A/C auto amp.

Transmission Data and Transmission Order

A/C auto amp. data is transmitted consecutively to each of the door motors following the form as shown in the
figure below.

JPIIA0489GB

JPIIA0490GB

JPIIA0491GB

Revision: 2008 October

2009 Murano

AUTOMATIC AIR CONDITIONER SYSTEM

HAC-141

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

HAC

START:

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

ADDRESS:

• Data sent from the A/C auto amp. is selected according to data-based decisions made by the mode door

motor, the air mix door motors, the upper ventilator door motor and the 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 has no error, door con-
trol begins.

• If an error exists, the received data is rejected and corrected the 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 is then compiled. The error

check prevents corrupted data from being used by the mode door motor, the air mix door motors, the upper
ventilator door motor 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 A/C auto amp. This completes one data transmission and control cycle.

Component Part Location

INFOID:0000000003469262

ENGINE COMPARTMENT

JPIIA0492GB

Revision: 2008 October

2009 Murano

HAC-142

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

AUTOMATIC AIR CONDITIONER SYSTEM

PASSENGER COMPARTMENT

Refrigerant pressure sensor

Compressor (magnet clutch)

Ambient sensor

JPIIA0607ZZ

Revision: 2008 October

2009 Murano

AUTOMATIC AIR CONDITIONER SYSTEM

HAC-143

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

HAC

Intake door motor

Upper ventilator door motor

Air mix door motor (passenger side)

Air mix door motor (driver side)

Mode door motor

Sunload sensor

In-vehicle sensor

A/C auto amp.

Intake sensor

10. Blower motor

JPIIA0608ZZ

Revision: 2008 October

2009 Murano

HAC-144

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

AUTOMATIC AIR CONDITIONER SYSTEM

Component Description

INFOID:0000000003469263

Component

Reference

Refrigerant pressure sensor

EC-463, "Description"

Compressor

HAC-191, "Description"

Ambient sensor

HAC-163, "Description"

Intake door motor

HAC-182, "Description"

Upper ventilator door motor

HAC-184, "Description"

Air mix door motor (driver side)

HAC-175, "Description"

Air mix door motor (passenger side)

HAC-177, "Description"

Mode door motor

HAC-179, "Description"

Sunload sensor

HAC-172, "Description"

In-vehicle sensor

HAC-166, "Description"

A/C auto amp.

HAC-193, "A/C AUTO AMP. : Description"

Intake sensor

HAC-169, "Description"

Blower motor

HAC-187, "Description"

Revision: 2008 October

2009 Murano

MODE DOOR CONTROL SYSTEM

HAC-145

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

HAC

MODE DOOR CONTROL SYSTEM

System Diagram

INFOID:0000000003469269

System Description

INFOID:0000000003469270

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 A/C auto amp. receives data from each of the sensors.
• The A/C auto amp. sends the air mix door, the mode door, the upper ventilator door and the intake door

opening angle data to the air mix door motor LCU(s), the mode door motor LCU, the upper ventilator door
motor LCU and the intake door motor LCU.

• The air mix door motor(s), the mode door motor, the upper ventilator door motor and the intake door motor

read their respective signals according to the address signal. Opening angle indication signals received from
the A/C auto amp. and each of the motor position sensors are compared by the LCUs in each door motor
with the existing decision and opening angles.

• Next, HOT/COLD, DEF/VENT, OPEN/SHUT or FRE/REC operations is selected. The newly selected data is

returned to the A/C auto amp.

Door Motor Circuit

Mode Door Control Specification

JSIIA1543GB

JPIIA0495GB

Revision: 2008 October

2009 Murano

HAC-146

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

MODE DOOR CONTROL SYSTEM

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

JPIIA0767GB

Revision: 2008 October

2009 Murano

UPPER VENTILATOR DOOR CONTROL SYSTEM

HAC-147

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

HAC

UPPER VENTILATOR DOOR CONTROL SYSTEM

System Diagram

INFOID:0000000003469271

System Description

INFOID:0000000003469272

The upper ventilator door motor is attached to the heater & cooling unit assembly. The upper ventilator door
motor operates by the UPPER VENT switch ON/OFF. Motor rotation is conveyed to a rod which activates the
upper ventilator door.

SYSTEM OPERATION

• The A/C auto amp. receives data from each of the sensors.
• The A/C auto amp. sends air mix door, the mode door, the upper ventilator door and the intake door opening

angle data to the air mix door motor LCU(s), the mode door motor LCU, the upper ventilator door motor LCU
and the intake door motor LCU.

• The air mix door motor(s), the mode door motor, the upper ventilator door motor and the intake door motor

• Next, HOT/COLD, DEF/VENT, OPEN/SHUT or FRE/REC operations is selected. The newly selected data is

returned to the A/C auto amp.

Door Motor Circuit

Upper Ventilator Specification

JSIIA1544GB

JPIIA0495GB

Revision: 2008 October

2009 Murano

HAC-148

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

UPPER VENTILATOR DOOR CONTROL SYSTEM

UPPER VENT switch

MODE position

Upper ventilator door position

OFF

—

VENT or B/L

Open (Fully-open)

FOOT or D/F

Open (Intermediate)

DEF

Revision: 2008 October

2009 Murano

AIR MIX DOOR CONTROL SYSTEM

HAC-149

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

HAC

AIR MIX DOOR CONTROL SYSTEM

System Diagram

INFOID:0000000003469275

System Description

INFOID:0000000003469276

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

SYSTEM OPERATION

• The A/C auto amp. receives data from each of the sensors.
• The A/C auto amp. sends air mix door, the mode door, the upper ventilator door and the intake door opening

angle data to the air mix door motor LCU(s), the mode door motor LCU, the upper ventilator door motor LCU
and the intake door motor LCU.

• The air mix door motor(s), the mode door motor, the upper ventilator door motor and the intake door motor

• Next, HOT/COLD, DEF/VENT, OPEN/SHUT or FRE/REC operation is selected. The newly selected data is

returned to the A/C auto amp.

Door Motor Circuit

Air Mix Door Control Specification

JSIIA1545GB

JPIIA0495GB

Revision: 2008 October

2009 Murano

HAC-150

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

AIR MIX DOOR CONTROL SYSTEM

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

C (60

F), air mix door is set on full cold, and when the tempera-

ture is set at 32

C (90

F), it is set to full hot.

JPIIA0633GB

Revision: 2008 October

2009 Murano

INTAKE DOOR CONTROL SYSTEM

HAC-151

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

HAC

INTAKE DOOR CONTROL SYSTEM

System Diagram

INFOID:0000000003469277

System Description

INFOID:0000000003469278

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 in shifting mode position D/F, if the DEF or OFF switches are
pressed, or when the A/C switch is OFF, the A/C auto amp. sets the intake door to the FRE position.

Door Motor Circuit

Intake Door Control Specification

JSIIA1546GB

JPIIA0495GB

Revision: 2008 October

2009 Murano

HAC-152

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

INTAKE DOOR CONTROL SYSTEM

Intake door position is basically set to the FRE when the FRE indica-
tor of the DEF switch and the intake switch turn ON, and set on the
REC when the REC indicator of intake switch turns ON.
The intake door automatic control selects the FRE, the 20%FRE, or
the REC depending on the target air mix door opening angle, based
on in-vehicle temperature, ambient temperature, and sunload.

JPIIA0634GB

Revision: 2008 October

2009 Murano

BLOWER MOTOR CONTROL SYSTEM

HAC-153

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

HAC

BLOWER MOTOR CONTROL SYSTEM

System Diagram

INFOID:0000000003469281

System Description

INFOID:0000000003469282

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.
By pressing the 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.

SYSTEM OPERATION

System operation

• For air flow, the manual selection (1-7) with the fan control dial has

priority.

• If the AUTO switch is pressed or if the DEF switch is pressed while

in the OFF condition, it changes to the automatic control by A/C
auto amp.

• When increasing the air flow, it changes the duty ratio of the blower

motor drive signal to prevent the air flow from suddenly increasing.

• There are the following types of air flow control: starting air flow

control, starting air flow control at low coolant temperature, starting
air flow control at high in-vehicle temperature, and air flow control
at actuator operation in addition to manual control, normal auto-
matic air flow control.

Normal automatic air flow control

• When the target temperature is set by the temperature control dial of preset switch, the A/C auto amp. per-

forms the calculation and decides the target according to the signal from each sensor.

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

so that the air flow becomes the target air flow.

• The minimum air flow will change according to the sunload when the air discharge outlet is VENT or B/L.

JSIIA1547GB

JSIIA0999ZZ

Revision: 2008 October

2009 Murano

HAC-154

< FUNCTION DIAGNOSIS >

[WITH 7 INCH DISPLAY]

BLOWER MOTOR CONTROL SYSTEM

Fan Speed Control Specification

Starting air flow control

• When starting the automatic control of air flow, the system gradually increases the duty ratio of the blower

motor drive signal to prevent too much air from blowing.

• The time period from when the air flow changes from LO to HI is approximately 8 seconds.
• It becomes the starting air flow control at low coolant temperature according to the calculation result of the A/

C auto amp. and engine coolant temperature [approximately 58

C (136

F) or less] during the automatic air

flow control.

• Do not perform the starting air flow control when the air discharge outlet is set to DEF.

Starting Fan Speed Control

Start up from COLD SOAK Condition (Automatic mode)
In cold start up condition where the engine coolant temperature is below 58

C (136

F), the blower does not

operate for a short period of time (up to 150 seconds). The exact start delay time varies depending on the
ambient temperature and engine coolant temperature.
In the most extreme case (very low ambient temperature) the blower start delay is 150 seconds as described
above. After this delay, the blower will operate at low speed until the engine coolant temperature rises above
58

C (136

F), and then the blower speed increases to the objective speed.

Start up from usual or HOT SOAK Condition (Automatic mode)
The blower will begin operation momentarily after the AUTO switch is pressed. The blower speed rises gradu-
ally to the objective speed over a time period of 3 seconds or less (actual time depends on the objective
blower speed).

JPIIA0635GB

Revision: 2008 October

2009 Murano

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