2004 INFINITI QX56 air conditioner

-1QUICK REFERENCE INDEX AGENERAL INFORMATIONGIGeneral InformationBENGINEEMEngine MechanicalLUEngine Lubrication SystemCOEngine Cooling SystemECEngine Control SystemFLFuel SystemEXExhaust SystemACCAccelerator Control SystemCTRANSMISSION/
TRANSAXLEATAutomatic TransmissionDDRIVELINE/AXLETFTransferPRPropeller ShaftFFDFront Final DriveRFDRear Final DriveFAXFront AxleRAXRear AxleESUSPENSIONFSUFront SuspensionRSURear SuspensionWTRoad Wheels & TiresFBRAKESBRBrake SystemPBParking Brake SystemBRCBrake Control SystemGSTEERINGPSPower Steering SystemHRESTRAINTSSBSeat BeltsSRSSupplemental Restraint System (SRS)IBODYBLBody, Lock & Security SystemGWGlasses, Window System & MirrorsRFRoofEIExterior & InteriorIPInstrument PanelSESeatAPAdjustable PedalsJAIR CONDITIONERATCAutomatic Air ConditionerKELECTRICALSCStarting & Charging SystemLTLighting SystemDIDriver Information SystemWWWiper, Washer & HornBCSBody Control SystemLANLAN SystemAVAudio Visual, Navigation & Telephone SystemACSAuto Cruise Control SystemPGPower Supply, Ground & Circuit ElementsLMAINTENANCEMAMaintenanceMINDEXIDXAlphabetical IndexEdition: February 2004
Revision: August 2007BDACEFGHIJKLM

ATC-1
AUTOMATIC AIR CONDITIONER
J AIR CONDITIONER
CONTENTS
C
D
E
F
G
H
I
K
L
M
SECTION AT C
A
B
AT C
Revision: August 20072004 QX56 PRECAUTIONS .......................................................... 5
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 5
Precautions for Working with HFC-134a (R-134a) ..... 5
Contaminated Refrigerant ........................................ 5
General Refrigerant Precautions .............................. 6
Precautions for Leak Detection Dye ......................... 6
A/C Identification Label ............................................ 7
Precautions for Refrigerant Connection ................... 7
FEATURES OF NEW TYPE REFRIGERANT
CONNECTION ...................................................... 7
O-RING AND REFRIGERANT CONNECTION ..... 8
Precautions for Servicing Compressor ....................11
Precautions for Service Equipment .........................11
RECOVERY/RECYCLING EQUIPMENT .............11
ELECTRONIC LEAK DETECTOR .......................11
VACUUM PUMP ................................................. 12
MANIFOLD GAUGE SET .................................... 12
SERVICE HOSES ............................................... 12
SERVICE COUPLERS ........................................ 13
REFRIGERANT WEIGHT SCALE ...................... 13
CHARGING CYLINDER ...................................... 13
Wiring Diagrams and Trouble Diagnosis ................ 13
PREPARATION ......................................................... 14
Special Service Tools ............................................. 14
HFC-134a (R-134a) Service Tools and Equipment ... 14
Commercial Service Tools ...................................... 17
REFRIGERATION SYSTEM ..................................... 18
Refrigerant Cycle ................................................... 18
REFRIGERANT FLOW ....................................... 18
Refrigerant System Protection ............................... 18
REFRIGERANT PRESSURE SENSOR ............. 18
PRESSURE RELIEF VALVE .............................. 19
Component Layout ................................................. 20
FRONT REFRIGERATION SYSTEM .................. 20
REAR REFRIGERATION SYSTEM .................... 21LUBRICANT .............................................................. 22
Maintenance of Lubricant Quantity in Compressor ... 22
LUBRICANT ........................................................ 22
CHECKING AND ADJUSTING ............................ 22
AIR CONDITIONER CONTROL ............................... 24
Description .............................................................. 24
Operation ................................................................ 24
AIR MIX DOORS CONTROL .............................. 24
FAN SPEED CONTROL ...................................... 24
INTAKE DOOR CONTROL ................................. 24
MODE DOOR CONTROL ................................... 24
DEFROSTER DOOR CONTROL ........................ 24
MAGNET CLUTCH CONTROL ........................... 25
SELF-DIAGNOSTIC SYSTEM ............................ 25
Description of Control System ................................ 26
Control Operation ................................................... 26
DISPLAY SCREEN .............................................. 27
AUTO SWITCH ................................................... 27
TEMPERATURE DIAL (DRIVER) ........................ 27
TEMPERATURE DIAL (PASSENGER) ............... 27
RECIRCULATION SWITCH () ............................. 27
DEFROSTER () SWITCH .................................... 27
REAR WINDOW DEFOGGER SWITCH ............. 27
OFF SWITCH (HOLD FAN DOWN SWITCH
UNTIL SYSTEM SHUTS OFF) ............................ 27
A/C SWITCH ....................................................... 27
MODE SWITCH .................................................. 27
FRONT FAN SWITCH ......................................... 27
REAR FAN SWITCH (FRONT) ............................ 27
REAR TEMPERATURE/MODE DIAL (FRONT) ... 27
REAR TEMPERATURE/MODE DIAL (REAR) .... 28
REAR FAN CONTROL SWITCH (REAR) ........... 28
Discharge Air Flow ................................................. 29
FRONT ................................................................ 29
REAR .................................................................. 29
System Description (Front) ..................................... 30
CONTROLS AND THEIR FUNCTIONS .............. 30
System Description (Rear) ..................................... 31
CONTROLS AND THEIR FUNCTIONS .............. 31
CAN Communication System Description .............. 32

ATC-6
PRECAUTIONS
Revision: August 20072004 QX56

If you choose to perform the repair, recover the refrigerant using only dedicated equipment and contain-
ers. Do not recover contaminated refrigerant into your existing service equipment. If your facility
does not have dedicated recovery equipment, you may contact a local refrigerant product retailer for avail-
able service. This refrigerant must be disposed of in accordance with all federal and local regulations. In
addition, replacement of all refrigerant system components on the vehicle is recommended.

If the vehicle is within the warranty period, the air conditioner warranty is void. Please contact NISSAN
Customer Affairs for further assistance.
General Refrigerant PrecautionsEJS002BI
WAR NIN G:

Do not release refrigerant into the air. Use approved recovery/recycling equipment to capture the
refrigerant every time an air conditioning system is discharged.

Always wear eye and hand protection (goggles and gloves) when working with any refrigerant or
air conditioning system.

Do not store or heat refrigerant containers above 52°C (125°F).

Do not heat a refrigerant container with an open flame; if container warming is required, place the
bottom of the container in a warm pail of water.

Do not intentionally drop, puncture, or incinerate refrigerant containers.

Keep refrigerant away from open flames: poisonous gas will be produced if refrigerant burns.

Refrigerant will displace oxygen, therefore be certain to work in well ventilated areas to prevent
suffocation.

Do not pressure test or leak test HFC-134a (R-134a) service equipment and/or vehicle air condi-
tioning systems with compressed air during repair. Some mixtures of air and HFC-134a (R-134a)
have been shown to be combustible at elevated pressures. These mixtures, if ignited, may cause
injury or property damage. Additional health and safety information may be obtained from refriger-
ant manufacturers.
Precautions for Leak Detection DyeEJS002BJ

The A/C system contains a fluorescent leak detection dye used for locating refrigerant leaks. An ultraviolet
(UV) lamp is required to illuminate the dye when inspecting for leaks.

Always wear fluorescence enhancing UV safety goggles to protect your eyes and enhance the visibility of
the fluorescent dye.

The fluorescent dye leak detector is not a replacement for an electronic refrigerant leak detector. The fluo-
rescent dye leak detector should be used in conjunction with an electronic refrigerant leak detector (J-
41995).

For your safety and the customer's satisfaction, read and follow all manufacturer's operating instructions
and precautions prior to performing work.

A compressor shaft seal should not be repaired because of dye seepage. The compressor shaft seal
should only be repaired after confirming the leak with an electronic refrigerant leak detector (J-41995).

Always remove any dye from the leak area after repairs are complete to avoid a misdiagnosis during a
future service.

Do not allow dye to come into contact with painted body panels or interior components. If dye is spilled,
clean immediately with the approved dye cleaner. Fluorescent dye left on a surface for an extended period
of time cannot be removed .

Do not spray the fluorescent dye cleaning agent on hot surfaces (engine exhaust manifold, etc.).

Do not use more than one refrigerant dye bottle (1/4 ounce / 7.4 cc) per A/C system.

Leak detection dyes for HFC-134a (R-134a) and CFC-12 (R-12) A/C systems are different. Do not use
HFC-134a (R-134a) leak detection dye in CFC-12 (R-12) A/C systems or CFC-12 (R-12) leak detection
dye in HFC-134a (R-134a) A/C systems or A/C system damage may result.

The fluorescent properties of the dye will remain for over three (3) years unless a compressor failure
occurs.

ATC-10
PRECAUTIONS
Revision: August 20072004 QX56
CAUTION:
The new and former refrigerant connections use different O-ring configurations. Do not confuse O-
rings since they are not interchangeable. If a wrong O-ring is installed, refrigerant will leak at or
around the connection.
O-Ring Part Numbers and Specifications
*: Always check with the Parts Department for the latest parts information.
WAR NIN G:
Make sure all refrigerant is discharged into the recycling equipment and the pressure in the system is
less than atmospheric pressure. Then gradually loosen the discharge side hose fitting and remove it.
CAUTION:
When replacing or cleaning refrigerant cycle components, observe the following.

When the compressor is removed, store it in the same position as it is when mounted on the car.
Failure to do so will cause lubricant to enter the low pressure chamber.

When connecting tubes, always use a torque wrench and a back-up wrench.

After disconnecting tubes, immediately plug all openings to prevent entry of dirt and moisture.

When installing an air conditioner in the vehicle, connect the pipes as the final stage of the opera-
tion. Do not remove the seal caps of pipes and other components until just before required for
connection.

Allow components stored in cool areas to warm to working area temperature before removing seal
caps. This prevents condensation from forming inside A/C components.

Thoroughly remove moisture from the refrigeration system before charging the refrigerant.

Always replace used O-rings.

When connecting tube, apply lubricant to circle of the O-rings shown in illustration. Be careful not
to apply lubricant to threaded portion.
Lubricant name: NISSAN A/C System Oil Type DH-PS
Part number: KLH00-PAGS0

O-ring must be closely attached to dented portion of tube.

When replacing the O-ring, be careful not to damage O-ring and tube.

Connect tube until you hear it click, then tighten the nut or bolt by hand until snug. Make sure that
the O-ring is installed to tube correctly.
Connec-
tion typeO-ring
sizePart number* D mm (in) W mm (in)
New 8 92471 N8210 6.8 (0.268) 1.85 (0.0728)
Former 10 J2476 89956 9.25 (0.3642) 1.78 (0.0701)
New
1292472 N8210 10.9 (0.429) 2.43 (0.0957)
Former 92475 71L00 11.0 (0.433) 2.4 (0.094)
New
1692473 N8210 13.6 (0.535) 2.43 (0.0957)
Former 92475 72L00 14.3 (0.563) 2.3 (0.091)
New
1992474 N8210 16.5 (0.650) 2.43 (0.0957)
Former 92477 N8200 17.12 (0.6740) 1.78 (0.0701)
New 24 92195 AH300 21.8 (0.858) 2.4 (0.094)
SHA8 14 E

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.