INFINITI QX56 2006 Factory Service Manual

ATC-20
REFRIGERATION SYSTEM
Revision: November 20092006 QX56
Component LayoutEJS003X3
FRONT REFRIGERATION SYSTEM
WJIA0956E

REFRIGERATION SYSTEMATC-21
C
DE
F
G H
I
K L
M A
B
AT C
Revision: November 2009 2006 QX56
REAR REFRIGERATION SYSTEM
1. Defroster nozzle2. LH side demister duct3. LH ventilator duct
4. RH side demister duct 5. RH ventilator duct6. Center ventilator duct
7. Front heater and cooling unit assembly 8. Floor duct 9. Clips
10. Heat duct
1. Rear floor duct 2. Rear heater and cooling unit assembly 3. Rear lower overhead duct
4. Rear upper overhead duct
LJIA0142E

ATC-22
OIL
Revision: November 20092006 QX56
OILPFP:KLG00
Maintenance of Oil Quantity in CompressorEJS003X4
The oil in the compressor circulates through the system with the refrigerant. Add oil to compressor when
replacing any component or after a large refrigerant leakage has occurred. It is important to maintain the spec-
ified amount.
If oil quantity is not maintained properly, the following malfunctions may result:

Lack of oil: May lead to a seized compressor

Excessive oil: Inadequate cooling (thermal exchange interference)
OIL
Name: NISSAN A/C System Oil Type S (DH-PS) or equivalent
Part number: KLH00-PAGS0
CHECKING AND ADJUSTING
CAUTION:
If excessive oil leakage is noted, do not perform the oil return operation.
Start the engine and set the following conditions:
Test Condition

Engine speed: Idling to 1,200 rpm

A/C switch: On

Blower fan speed: MAX position

Temp. control: Optional [Set so that intake air temperature is 25° to 30 ° C (77 ° to 86 °F)]

Intake position: Recirculation ( )

Perform oil return operation for about ten minutes
Adjust the oil quantity according to the following table.
Oil Adjusting Procedure for Components Replacement Except Compressor
After replacing any of the following major components, add the correct amount of oil to the system.
Amount of oil to be added :

*1: If refrigerant leak is small, no addition of oil is needed.
Part replaced Oil to be added to system
Remarks
Amount of oil
m (US fl oz, Imp fl oz)
Front evaporator 75 (2.5, 2.6)—
Rear evaporator 75 (2.5, 2.6)—
Condenser 75 (2.5, 2.6)—
Liquid tank 5 (0.2, 0.2)Add if compressor is not replaced.
In case of refrigerant leak 30 (1.0, 1.1)
Large leak
— Small leak *1

OIL
ATC-23
C
D E
F
G H
I
K L
M A
B
AT C
Revision: November 2009 2006 QX56
Oil Adjustment Procedure for Compressor Replacement
1. Before connecting recovery/recycling equipment to vehicle, check recovery/recycling equipment gauges.
No refrigerant pressure should be displayed. If NG, recover refrigerant from equipment lines.
2. Connect recovery/recycling equipment to vehicle. Confirm refrigerant purity in supply tank using recovery/ recycling equipment and refrigerant identifier. If NG, refer to AT C - 5 , "
Contaminated Refrigerant" .
3. Confirm refrigerant purity in vehicle A/C system using recovery/recycling equipment and refrigerant identi- fier. If NG, refer to AT C - 5 , "
Contaminated Refrigerant" .
4. Discharge refrigerant into the refrigerant recovery/recycling equipment. Measure oil discharged into the recovery/recycling equipment.
5. Drain the oil from the “old” (removed) compressor into a graduated container and recover the amount of
oil drained.
6. Drain the oil from the “new ” compressor into a separate, clean container.
7. Measure an amount of new oil installed equal to amount drained from “old” compressor. Add this oil to
“new ” compressor through the suction port opening.
8. Measure an amount of new oil equal to the amount recovered during discharging. Add this oil to “new”
compressor through the suction port opening.
9. If the liquid tank also needs to be replaced, add an additional 5 m (0.2 US fl oz, 0.2 Imp fl oz) of oil at this time.
1. New compressor 2. Old compressor3. Recovery/recycling equipment
4. Measuring cup X 5. Measuring cup Y6. New oil
A. Drain oil from the new compressor into clean container B. Record amount of oil recovered C.
Add an additional 5 m (0.2 US fl oz,
0.2 Imp fl oz) of new oil when replac-
ing liquid tank
D. Install new oil equal to recorded amounts in measuring cups X plus Y
WJIA1716E

ATC-24
OIL
Revision: November 20092006 QX56
CAUTION:
Do not add this 5 m (0.2 US fl oz, 0.2 Imp fl oz) of oil if only replacing the compressor.

AIR CONDITIONER CONTROLATC-25
C
DE
F
G H
I
K L
M A
B
AT C
Revision: November 2009 2006 QX56
AIR CONDITIONER CONTROLPFP:27500
DescriptionEJS003X5
The front air control provides automatic regulation of the vehicle's interior temperature. The system is based
on the driver's and passenger's selected "set temperature", regardless of the outside temperature changes.
This is done by utilizing a microcomputer, also referred to as the front air control, which receives input signals
from the following seven sensors:

Ambient sensor

In-vehicle sensor

Intake sensor

Optical sensor (providing one input for driver and one input for passenger side)

PBR (Position Balanced Resistor)

Vehicle speed sensor (via CAN communication)

Engine coolant temperature (via CAN communication)
The front air control uses these signals (including the set temperature) to automatically control:

Outlet air volume

Air temperature

Air distribution
The front air control also provides separate regulation of the vehicle's interior temperature for the rear passen-
ger area. The system is based on the temperature and rear blower settings selected from rear control
switches located on the front air control, or from the temperature and rear blower settings selected from rear
control switches on the rear air control, when the front air control switches are set to the rear position.
The front air control is used to select:

Outlet air volume

Air temperature/distribution
OperationEJS003X6
AIR MIX DOORS 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.
BLOWER 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.
When AUTO switch is pressed, the blower motor starts to gradually increase air flow volume (if required).
When engine coolant temperature is low, the blower motor operation is delayed to prevent cool air from flow-
ing.
INTAKE DOOR CONTROL
The intake door is automatically controlled by the temperature setting, ambient temperature, in-vehicle tem-
perature, intake temperature, amount of sunload and by the 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.
DEFROSTER DOOR CONTROL
The defroster door is controlled by: Turning the defroster dial to front defroster.

ATC-26
AIR CONDITIONER CONTROL
Revision: November 20092006 QX56
MAGNET CLUTCH CONTROL
When A/C switch or DEF switch is pressed, front air control inputs compressor ON signal to BCM.
BCM sends compressor ON signal to ECM, 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.
Upon receipt of compressor ON signal from ECM, IPDM E/R turns air conditioner relay ON to operate com-
pressor.
SELF-DIAGNOSTIC SYSTEM
The self-diagnostic system is built into the front air control to quickly locate the cause of symptoms. Refer to
AT C - 5 6 , "
A/C System Self-diagnosis Function"
WJIA1163E

AIR CONDITIONER CONTROLATC-27
C
DE
F
G H
I
K L
M A
B
AT C
Revision: November 2009 2006 QX56
Description of Control SystemEJS003X7
The control system consists of input sensors, switches, the front air control (microcomputer) and outputs.
The relationship of these components is shown in the figure below:
Control OperationEJS003X8
Front air control
WJIA1917E
WJIA1714E

ATC-28
AIR CONDITIONER CONTROL
Revision: November 20092006 QX56
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 maintained at the set temperature selected by the oper-
ator.

When pressing AUTO switch, air inlet, air outlet, blower speed, and discharge air temperature are auto-
matically controlled.
TEMPERATURE CONTROL DIAL (TEMPERATURE CONTROL) (DRIVER SIDE)
Increases or decreases the set temperature.
TEMPERATURE CONTROL DIAL (TEMPERATURE CONTROL) (PASSENGER SIDE)
Increases or decreases the set temperature.
TEMPERATURE CONTROL DIAL (TEMPERATURE AND MODE CONTROL) (REAR)
Increases or decreases the set temperature. The mode also changes from foot at full hot setting, to foot/vent
mid-range (warm) setting, and then to panel on full cold setting.
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 turned ON, at the D/F position or in floor position.
DEFROSTER () SWITCH
Positions the air outlet doors to the defrost position. Also positions the intake doors to the outside air position.
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 (FRONT)
Controls the air discharge outlets.
FRONT BLOWER CONTROL DIAL
Manually control the blower speed. Seven speeds are available for manual control (as shown on the display
screen).

AIR CONDITIONER CONTROLATC-29
C
DE
F
G H
I
K L
M A
B
AT C
Revision: November 2009 2006 QX56
Rear Air Control
TEMPERATURE CONTROL DIAL (TEMPERATURE AND MODE CONTROL)
The temperature increases or decreases the set temperature. The mode also changes from foot at full hot set-
ting, to foot/vent at mid-range (warm) setting, and then to vent at full cold setting.
REAR BLOWER CONTROL DIAL
When the rear blower switch (front) is in the OFF position, the rear blower motor cannot operate.
When the rear blower switch (front) is in position (1-4), both the front and rear blower switch can control the
rear blower motor speed.
WJIA1042E