2010 INFINITI QX56 air condition

HAC-12
< FUNCTION DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
REFRIGERATION SYSTEM
PRESSURE RELIEF VALVE
The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor.
When the pressure of refrigerant in the system increases to an abnormal level [more than 2,990 kPa (30.5 kg/
cm
2, 433.6 psi)], the release port on the pressure relief valve automatically opens and releases refrigerant into
the atmosphere.
Revision: April 20092010 QX56

AUTOMATIC AIR CONDITIONER SYSTEMHAC-13
< FUNCTION DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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AUTOMATIC AIR CONDITIONER SYSTEM
Control System DiagramINFOID:0000000005147675
CONTROL SYSTEM
The control system consists of input sensors, switches, the A/C auto amp.(microcomputer) and outputs.
The relationship of these components is shown in the figure below:
Control System DescriptionINFOID:0000000005147676
CONTROL OPERATION
AWIIA0088GB
Revision: April 20092010 QX56

HAC-14
< FUNCTION DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AUTOMATIC AIR CONDITIONER SYSTEM
A/C auto amp.
DISPLAY SCREEN
Displays the operational status of the system.
AUTO SWITCH
• The compressor, intake door, air mix doors, outlet
doors and blower speed are automatically controlled so
that the in-vehicle temperature will reach, and be mainta ined at the set temperature selected by the operator.
• When pressing AUTO switch, air inlet, air outlet, bl ower speed, and discharge air temperature are automati-
cally controlled.
TEMPERATURE CONTROL DIAL (DRIVER)
Increases or decreases the set temperature.
TEMPERATURE CONTROL DIAL (PASSENGER)
Increases or decreases the set temperature.
RECIRCULATION ( ) SWITCH
• When REC switch is ON, REC switch indicator turns ON, and air inlet is set to REC.
• When REC switch is turned OFF, or when compressor is turned from ON to OFF, REC switch is automati-
cally turned OFF. REC mode can be re-entered by pressing REC switch again.
• REC switch is not operated when DEF switch is tur ned ON, at the D/F position, or in floor position.
DEFROSTER ( ) SWITCH
Positions the air outlet doors to the defrost position. Al so positions the intake doors to the outside air position,
and turns A/C compressor ON.
REAR WINDOW DEFOGGER SWITCH
When switch is ON, rear window and door mirrors are defogged.
OFF SWITCH
The compressor and blower are OFF, the intake doors are set to the outside air position, and the air outlet
doors are set to the foot (75% foot and 25% defrost) position.
A/C SWITCH
The compressor is ON or OFF.
(Pressing the A/C switch when the AUTO switch is ON will turn off the A/C switch and compressor.)
MODE SWITCH
Controls the air discharge outlets.
FRONT BLOWER CONTROL SWITCHES
Manually control the blower speed.
AWIIA0081ZZ
Revision: April 20092010 QX56

AUTOMATIC AIR CONDITIONER SYSTEMHAC-15
< FUNCTION DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Rear Air Controls
REAR TEMPERATURE CONTROL DIAL (FRONT/REAR)
The temperature increases or dec reases the set temperature.
REAR MODE SWITCHES (FRONT/REAR)
Controls the air discharge outlets.
REAR BLOWER CONTROL DIAL (FRONT)
When the REAR CTRL switch is in the off (indicator off) the rear air control (front) controls the rear blower
motor speed regardless of the rear air control (rear) blow er control dial (rear) position. The rear air control
(front) controls the blower motor speed.
REAR BLOWER CONTROL DIAL (REAR)
When the REAR CTRL switch is in the on (indicator on) the rear air control (rear) controls the rear blower
motor speed regardless of the rear air control (front) blow er control dial (front) position. The rear air control
(rear) controls the blower motor speed.
MAGNET CLUTCH CONTROL
When A/C switch or DEF switch is pressed, A/ C auto amp. inputs compressor ON signal to BCM.
BCM sends compressor ON signal to ECM and A/C auto amp., via CAN communication line.
ECM judges whether compressor can be turned ON, based on each sensor status (refrigerant pressure sen-
sor signal, throttle angle sensor, etc.). If it judges compressor can be turned ON, it sends compressor ON sig-
nal to IPDM E/R, via CAN communication line.
AWIIA0082ZZ
1. Rear air control (front )2. Rear air control (rear)
AWIIA1069GB
Revision: April 20092010 QX56

HAC-16
< FUNCTION DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AUTOMATIC AIR CONDITIONER SYSTEM
Upon receipt of compressor ON signal from ECM, IPDM E/R turns air conditioner relay ON to operate com-
pressor.
Discharge Air Flow (Front)INFOID:0000000005147677
Discharge Air Flow (Rear)INFOID:0000000005147678

Mode door positionAir outlet/distribution
Vent Foot Defroster
95% 5% —
60% 40% —
—7 0% 3 0%
—6 0% 4 0%
—1 0% 9 0%
AWIIA0818ZZ
Revision: April 20092010 QX56

AUTOMATIC AIR CONDITIONER SYSTEMHAC-17
< FUNCTION DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Mode door position Air outlet/distribution
Ve n t F o o t
100% —
50% 50%
—1 00 %
WJIA0541E
Revision: April 20092010 QX56

HAC-18
< FUNCTION DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AUTOMATIC AIR CONDITIONER SYSTEM
Switches And Their Cont rol Function (Front)
INFOID:0000000005147679
WJIA1680E
AWIIA0083GB
Revision: April 20092010 QX56

AUTOMATIC AIR CONDITIONER SYSTEMHAC-19
< FUNCTION DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Switches And Their C ontrol Function (Rear)INFOID:0000000005147680
AWIIA0275GB
AWIIA0084GB
Revision: April 20092010 QX56