2004 INFINITI QX56 Air

PRECAUTIONS
ATC-11
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: August 20072004 QX56

After connecting line, conduct leak test and make sure that there is no leakage from connections.
When the gas leaking point is found, disconnect that line and replace the O-ring. Then tighten con-
nections of seal seat to the specified torque.
Precautions for Servicing CompressorEJS002BM

Plug all openings to prevent moisture and foreign matter from entering.

When the compressor is removed, store it in the same position as it is when mounted on the car.

When replacing or repairing compressor, follow “Maintenance of Lubricant Quantity in Compres-
sor” exactly. Refer to ATC-22, "
Maintenance of Lubricant Quantity in Compressor" .

Keep friction surfaces between clutch and pulley clean. If the surface is contaminated with lubri-
cant, wipe it off by using a clean waste cloth moistened with thinner.

After compressor service operation, turn the compressor shaft by hand more than 5 turns in both
directions. This will equally distribute lubricant inside the compressor. After the compressor is
installed, let the engine idle and operate the compressor for 1 hour.

After replacing the compressor magnet clutch, apply voltage to the new one and check for normal
operation. Refer to ATC-167, "
Removal and Installation for Compressor Clutch"
Precautions for Service EquipmentEJS002BN
RECOVERY/RECYCLING EQUIPMENT
Follow the manufacturer's instructions for machine operation and machine maintenance. Never introduce any
refrigerant other than that specified into the machine.
ELECTRONIC LEAK DETECTOR
Follow the manufacturer's instructions for tester operation and tester maintenance.
RHA861F

PRECAUTIONS
ATC-13
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: August 20072004 QX56
SERVICE COUPLERS
Never attempt to connect HFC-134a (R-134a) service couplers to a
CFC-12 (R-12) A/C system. The HFC-134a (R-134a) couplers will
not properly connect to the CFC-12 (R-12) system. If an improper
connection is attempted, discharging and contamination may occur.
REFRIGERANT WEIGHT SCALE
Verify that no refrigerant other than HFC134a (R-134a) and specified
lubricants have been used with the scale. If the scale controls refrig-
erant flow electronically, the hose fitting must be 1/2”-16 ACME.
CHARGING CYLINDER
Using a charging cylinder is not recommended. Refrigerant may be vented into air from cylinder's top valve
when filling the cylinder with refrigerant. Also, the accuracy of the cylinder is generally less than that of an
electronic scale or of quality recycle/recharge equipment.
Wiring Diagrams and Trouble DiagnosisEJS002BO
When you read wiring diagrams, refer to the following:

GI-15, "How to Read Wiring Diagrams"

PG-4, "POWER SUPPLY ROUTING CIRCUIT"
When you perform trouble diagnosis, refer to the following:

GI-11, "How to Follow Trouble Diagnoses"

GI-27, "How to Perform Efficient Diagnosis for an Electrical Incident"
Shut-off valve rotation A/C service valve
Clockwise Open
Counterclockwise Close
RHA273D
RHA274D

ATC-16
PREPARATION
Revision: August 20072004 QX56
(J-39183-C)
Manifold gauge set (with hoses
and couplers)Identification:

The gauge face indicates R-134a.
Fitting size-Thread size

1/2"-16 ACME
Service hoses

High side hose
(J-39500-72B)

Low side hose
(J-39500-72R)

Utility hose
(J-39500-72Y)
Hose color:

Low side hose: Blue with black stripe

High side hose: Red with black stripe

Utility hose: Yellow with black stripe
or green with black stripe
Hose fitting to gauge:

1/2"-16 ACME
Service couplers

High side coupler
(J-39500-20A)

Low side coupler
(J-39500-24A)
Hose fitting to service hose:

M14 x 1.5 fitting is optional or perma-
nently attached.
(J-39699)
Refrigerant weight scaleFor measuring of refrigerant
Fitting size-Thread size

1/2"-16 ACME
(J-39649)
Vacuum pump
(Including the isolator valve)
Capacity:

Air displacement: 4 CFM

Micron rating: 20 microns

Oil capacity: 482 g (17 oz)
Fitting size-Thread size

1/2"-16 ACME Tool number
(Kent-Moore No.)
Tool nameDescription
RJIA0196E
S-NT201
S-NT202
S-NT200
S-NT203

ATC-22
LUBRICANT
Revision: August 20072004 QX56
LUBRICANTPFP:KLG00
Maintenance of Lubricant Quantity in CompressorEJS002BV
The lubricant in the compressor circulates through the system with the refrigerant. Add lubricant to compres-
sor when replacing any component or after a large refrigerant leakage has occurred. It is important to maintain
the specified amount.
If lubricant quantity is not maintained properly, the following malfunctions may result:

Lack of lubricant: May lead to a seized compressor

Excessive lubricant: Inadequate cooling (thermal exchange interference)
LUBRICANT
Name: NISSAN A/C System Lubricant Type S (DH-PS)
Part number: KLH00-PAGS0
CHECKING AND ADJUSTING
CAUTION:
If excessive lubricant leakage is noted, do not perform the lubricant return operation.
Start the engine and set the following conditions:
test condition

Engine speed: Idling to 1,200 rpm

A/C switch: On

Blower 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 lubricant return operation for about ten minutes
Adjust the lubricant quantity according to the following table.
Lubricant Adjusting Procedure for Components Replacement Except Compressor
After replacing any of the following major components, add the correct amount of lubricant to the system.
Amount of Lubricant to be Added
*1: If refrigerant leak is small, no addition of lubricant is needed.
Lubricant 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 lubricant discharged into
the recovery/recycling equipment.
5. Drain the lubricant from the “old” (removed) compressor into a graduated container and recover the
amount of lubricant drained.
6. Drain the lubricant from the “new” compressor into a separate, clean container.
Part replacedLubricant to be added to system
Remarks
Amount of lubricant
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 leak30 (1.0, 1.1) Large leak
— Small leak *1

ATC-24
AIR CONDITIONER CONTROL
Revision: August 20072004 QX56
AIR CONDITIONER CONTROLPFP:27500
DescriptionEJS002BW
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 that is part of the front air control, which receives input signals from
the following five sensors:

Ambient sensor

In-vehicle sensor

Intake sensor

Optical sensor (one sensor for driver and passenger side)

PBR (position balanced resistor)
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 on the front air control
rear fan switch (front) and rear temperature/mode dial (front), or from the rear fan switch (rear) and rear tem-
perature/mode dial (rear) on the rear air control, when the rear fan switch (front) is set to the rear (R) position.
The front air control or rear air control is used to select:

Outlet air volume

Air temperature/mode distribution
OperationEJS002BX
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.
FAN SPEED CONTROL
Blower speed is automatically controlled based on temperature setting, ambient temperature, in-vehicle tem-
perature, 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 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.

AIR CONDITIONER CONTROL
ATC-25
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: August 20072004 QX56
MAGNET CLUTCH CONTROL
When the A/C or DEF switch is activated, the front air control outputs a compressor ON signal to the BCM.
Upon receiving this input, the BCM sends a compressor ON signal to the ECM via CAN communication lines.
The ECM then judges whether the compressor can be turned ON, based on each sensor status (refrigerant
pressure sensor signal, throttle angle sensor, etc.). If it determines the compressor can be turned ON, a com-
pressor ON signal is sent to the IPDM E/R via CAN communication lines.
Upon receipt of a compressor ON signal, the IPDM E/R turns ON the A/C relay which engages the magnet
clutch and operates the A/C compressor.
SELF-DIAGNOSTIC SYSTEM
A self-diagnostic system is built into the front air control to quickly locate the cause of symptoms. Refer to
ATC-53, "
A/C System Self-diagnosis Function"
WJIA0751E

ATC-26
AIR CONDITIONER CONTROL
Revision: August 20072004 QX56
Description of Control SystemEJS002BY
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 OperationEJS002BZ
Front air control
WJIA0755E
WJIA0756E

AIR CONDITIONER CONTROL
ATC-27
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: August 20072004 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.
TEMPERATURE DIAL (DRIVER)
Increases or decreases the driver zone temperature.
TEMPERATURE DIAL (PASSENGER)
Increases or decreases the passenger zone temperature.
RECIRCULATION SWITCH ()

When pressed an indicator turns ON in the display, and air inlet is set to recirculation mode.

Recirculation mode is cancelled by pressing the switch again, turning ON the front defroster, pressing the
OFF switch, or pressing the A/C switch to turn off the A/C system and compressor.
DEFROSTER () SWITCH
Positions the air outlet doors to the defrost position. Also positions the intake door to the outside air position.
REAR WINDOW DEFOGGER SWITCH
When switch is ON, rear window is defogged.
OFF SWITCH (HOLD FAN DOWN SWITCH UNTIL SYSTEM SHUTS OFF)
The compressor and blower are OFF, the intake door is 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 FAN SWITCH
Manually controls the blower speed. Seven speeds are available for manual control (as shown on the display
screen).
REAR FAN SWITCH (FRONT)
Manually controls the rear blower speed. Four speeds are available for manual control. When the rear fan
switch (front) is in the off (0) position, the rear blower motor cannot operate. Position (R) allows control of rear
blower speed and rear temperature/mode operation to be transferred to rear air control.
REAR TEMPERATURE/MODE DIAL (FRONT)
Increases or decreases the rear zone temperature and adjusts the mode simultaneously. FLOOR is full hot
setting, FLOOR/PANEL is warm setting, and PANEL is full cold setting.