INFINITI QX56 2007 Factory Service Manual

ATC-1
AIR CONDITIONER
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CONTENTS
AUTOMATIC AIR CONDITIONER
SERVICE INFORMATION .. ..........................3
PRECAUTIONS .............................................. .....3
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
3
Precaution for Working with HFC-134a (R-134a) ......3
Contaminated Refrigerant .........................................3
General Refrigerant Precaution ................................4
Precaution for Leak Detection Dye ...........................4
A/C Identification Label .............................................4
Precaution for Refrigerant Connection ......................4
Precaution for Service of Compressor ................ ......9
Precaution for Service Equipment ....................... ......9
PREPARATION ..................................................12
Special Service Tool ........................................... ....12
HFC-134a (R-134a) Service Tool and Equipment ....12
Commercial Service Tool ........................................14
REFRIGERATION SYSTEM ..............................16
Refrigerant Cycle ................................................ ....16
Refrigerant System Protection ................................16
Component Part Location ................................... ....17
OIL ......................................................................20
Maintenance of Oil Quantity in Compressor ....... ....20
AIR CONDITIONER CONTROL .........................22
Description .......................................................... ....22
Operation ................................................................22
Description of Control System .................................23
Control Operation ....................................................24
Discharge Air Flow ..................................................26
System Description (Front) .....................................27
System Description (Rear) .................................. ....28
CAN Communication System Description ...............29
TROUBLE DIAGNOSIS .....................................30
CONSULT-II Function (HVAC) ............................ ....30
CONSULT-II Function (BCM) ..................................31
How to Perform Trouble Diagnosis for Quick and
Accurate Repair ................................................... ....
32
Component Parts and Harness Connector Loca-
tion ...........................................................................
32
Schematic ................................................................36
Wiring Diagram - A/C,A - .........................................37
Front Air Control Terminal and Reference Value ....47
A/C System Self-Diagnosis Function .......................48
Operational Check (Front) ................................... ....50
Operational Check (Rear) ........................................51
Power Supply and Ground Circuit for Front Air
Control ................................................................. ....
52
Mode Door Motor Circuit .........................................54
Air Mix Door Motor Circuit ................................... ....59
Intake Door Motor Circuit .........................................70
Defroster Door Motor Circuit ....................................74
Front Blower Motor Circuit .......................................78
Rear Blower Motor Circuit ................................... ....85
Rear Air Control Circuit ............................................93
Magnet Clutch Circuit ..............................................96
Insufficient Cooling ................................................100
Insufficient Heating ................................................108
Noise .....................................................................109
Self-Diagnosis .......................................................111
Memory Function ...................................................112
Water Valve Circuit ................................................113
Ambient Sensor Circuit ..........................................114
In-vehicle Sensor Circuit ........................................116
Optical Sensor Circuit ............................................119
Intake Sensor Circuit .............................................120
CONTROL UNIT ..............................................123
Removal and Installation .......................................123
AMBIENT SENSOR ........................................124
Removal and Installation .......................................124
IN-VEHICLE SENSOR ....................................125
Removal and Installation .......................................125
OPTICAL SENSOR .........................................126

ATC-2
Removal and Installation .......................................126
INTAKE SENSOR ............................................127
Removal and Installation ..................................... ..127
BLOWER MOTOR ...........................................128
Component .......................................................... ..128
Removal and Installation .......................................128
IN-CABIN MICROFILTER ................................130
Removal and Installation ..................................... ..130
HEATER & COOLING UNIT ASSEMBLY .......132
Component .......................................................... ..132
Removal and Installation .......................................133
HEATER CORE ...............................................135
Component .......................................................... ..135
Removal and Installation .......................................136
DEFROSTER DOOR MOTOR .........................138
Removal and Installation ..................................... ..138
INTAKE DOOR MOTOR ..................................139
Removal and Installation ..................................... ..139
MODE DOOR MOTOR ....................................140
Removal and Installation ..................................... ..140
AIR MIX DOOR MOTOR ..................................141
Component .......................................................... ..141
Removal and Installation .......................................141
VARIABLE BLOWER CONTROL ...................143
Removal and Installation ..................................... ..143
REAR BLOWER MOTOR RESISTOR ............144
Removal and Installation ..................................... ..144
DUCTS AND GRILLES ....................................145
Component .......................................................... .145
Removal and Installation .......................................148
REFRIGERANT LINES ................................... ..150
HFC-134a (R-134a) Service Procedure ............... .150
Component ...........................................................152
Removal and Installation for Compressor .............154
Removal and Installation for Compressor Clutch ..155
Removal and Installation for Low-Pressure Flexi-
ble Hose ............................................................... .
158
Removal and Installation for High-pressure Flexi-
ble Hose ............................................................... .
158
Removal and Installation for High-pressure Pipe ..158
Removal and Installation for Low-Pressure Pipe ..159
Removal and Installation for Rear High- and Low-
Pressure A/C and Heater Core Pipes .................. .
159
Removal and Installation for Underfloor Rear
High- and Low-Pressure A/C and Heater Core
Pipes .................................................................... .
160
Removal and Installation for Refrigerant Pressure
Sensor .................................................................. .
161
Removal and Installation for Condenser ...............161
Removal and Installation for Front Evaporator .....163
Removal and Installation for Rear Evaporator ......164
Removal and Installation for Front Expansion
Valve .....................................................................
165
Removal and Installation for Rear Expansion
Valve .................................................................... .
165
Checking of Refrigerant Leaks ..............................166
Checking System for Leaks Using the Fluorescent
Dye Leak Detector ................................................
166
Dye Injection .........................................................166
Electronic Refrigerant Leak Detector ....................167
SERVICE DATA AND SPECIFICATIONS
(SDS) ................................................................
170
Service Data and Specification (SDS) ..................170

PRECAUTIONSATC-3
< SERVICE INFORMATION >
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PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000003533217
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the SRS section.
• Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
Precaution for Workin g with HFC-134a (R-134a)INFOID:0000000003533218
WARNING:
• CFC-12 (R-12) refrigerant and HFC-134a (R-134a) refr igerant are not compatible. If the refrigerants
are mixed compressor failure is likely to occur. Refer to AT C - 3 , "
Contaminated Refrigerant". To
determine the purity of HFC-134a (R-134a) in the vehicle and recovery tank, use recovery/recycling
equipment and refrigerant identifier.
• Use only specified oil for the HFC-134a (R-134a) A/C system and HFC-134a (R-134a) components. If
oil other than that specifi ed is used, compressor fa ilure is likely to occur.
• The specified HFC-134a (R-134a) oil rapidly absorb s moisture from the atmosphere. The following
handling precautions must be observed:
- When removing refrigerant components from a vehicle, immediately cap (seal) the component to
minimize the entry of mois ture from the atmosphere.
- When installing refrigerant components to a vehicle, do not remove the caps (unseal) until just
before connecting the co mponents. Connect all refrigerant lo op components as quickly as possible
to minimize the entry of moisture into system.
- Only use the specified oil from a sealed container. Immediately reseal containers of oil. Without
proper sealing, oil will become moisture saturat ed and should not be used.
- Avoid breathing A/C refrigerant and oil vapor or mist. Exposure may irritate eyes, nose and throat.
Remove HFC-134a (R-134a) from the A/C system usi ng certified service equipment meeting require-
ments of SAE J2210 [HFC-134a (R-134a) recycling eq uipment], or J2209 [HFC-134a (R-134a) recovery
equipment]. If accidental system discharge occurs , ventilate work area before resuming service.
Additional health and safety information may be ob tained from refrigerant and oil manufacturers.
- Do not allow A/C oil to come in contact with styrofoam parts. Damage may result.
Contaminated RefrigerantINFOID:0000000003533219
If a refrigerant other than pure HFC-134a (R-134a) is identified in a vehicle, your options are:
• Explain to the customer that environmental regulations prohibit the release of contaminated refrigerant into
the atmosphere.
• Explain that recovery of the contaminated refri gerant could damage your service equipment and refrigerant
supply.
• Suggest the customer return the vehicle to the locati on of previous service where the contamination may
have occurred.
• If you choose to perform the repair, recover the refrigerant using only dedicated equipment and contain-
ers. Do not recover contaminated refriger ant into your existing service equipment. If your facility does

ATC-4
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PRECAUTIONS
not have dedicated recovery equipment, you may contact a local refrigerant product retailer for available ser-
vice. This refrigerant must be disposed of in acco rdance 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 Cus-
tomer Affairs for further assistance.
General Refrigerant PrecautionINFOID:0000000003533220
WARNING:
• Do not release refrigerant into th e 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: poisonou s gas will be produced if refrigerant burns.
• Refrigerant will displace oxygen, therefore be certa in to work in well ventilated areas to prevent suf-
focation.
• Do not pressure test or leak test HFC-134a (R-134a) service equipment and/or vehicle air condition-
ing 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 heal th and safety information may be obtained from refrigerant manu-
facturers.
Precaution for Leak Detection DyeINFOID:0000000003533221
• 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 conjuncti on with an electronic refrigerant leak detector (J-
41995).
• For your safety and the customer's satisfaction, r ead 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. Fluoresc ent 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 ov er three (3) years unless a compressor failure occurs.
A/C Identification LabelINFOID:0000000003533222
Vehicles with factory installed fluorescent dye have this identification label on the underside of hood.
Precaution for Refrigerant ConnectionINFOID:0000000003533223
A new type refrigerant connection has been introduced to al l refrigerant lines except the following locations.
• Expansion valve to cooling unit
• Evaporator pipes to evaporator (inside cooling unit)
• Refrigerant pressure sensor
FEATURES OF NEW TYPE REFRIGERANT CONNECTION

PRECAUTIONSATC-5
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• The O-ring has been relocated. It has also been provided with a groove for proper installation. This reduces the possibility of the O-ring being caught in, or damaged by , the mating part. The sealing direction of the O-
ring is now set vertically in relation to the contacting surface of the mating part to improve sealing character-
istics.
• The reaction force of the O-ring will not occur in the dire ction that causes the joint to pull out, thereby facili-
tating piping connections.
O-RING AND REFRIGERANT CONNECTION
SHA815E

ATC-6
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PRECAUTIONS
Front A/C Compressor and Condenser
WJIA1578E
1. High-pressure service valve 2. Grommet 3. High-pressure pipe
4. Refrigerant pressure sensor 5. Condenser 6. Compressor shaft seal
7. High-pressure flexible hose 8. Low-pressure flexible hose 9. Low-pressure service valve
10. Low-pressure pipe 11. Expansion valve (front) 12. Drain hose

PRECAUTIONSATC-7
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Rear A/C
CAUTION:
The new and former refrigerant connections use diffe rent 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
WJIA2315E
1. Rear heater and cooling unit assembly 2. Rear A/C pipes 3. Rear A/C heater core pipes
4. Rear heater core hose 5. Rear blower motor 6. Underfloor rear A/C pipes
7. Underfloor rear heater core pipes A. Bolt torque specifications B. Leak checking order (l - r)
C. Tightening torque D. Wrench size E. O-ring size
⇐ Front
NOTE: The O-ring size 8 is the high-side and the O-ring size 16 is the low-side.

ATC-8
< SERVICE INFORMATION >
PRECAUTIONS
*: Always check with the Parts Department for the latest parts information.
WARNING:
Make sure all refrigerant is discharged into the recycling equipment and the pressure in the system is
less than atmospheric pressure. Then gradually loo sen the discharge side hose fitting and remove it.
CAUTION:
When replacing or cleaning refrigeran t 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 oil to enter the low pressure chamber.
• When connecting tubes, always use a torque wrench and a back-up wrench.
• After disconnecting tubes, immedi ately 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 othe r components until just before required for con-
nection.
• 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 refrigerat ion system before charging the refrigerant.
• Always replace used O-rings.
• When connecting tube, apply oil to circle of the O-rings shown in illustration. Be careful not to apply
oil to threaded portion.
Oil name: NISSAN A/C System Oil Type S or equivalent
• 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 cl ick, then tighten the nut or bolt by hand until snug. Make sure that
the O-ring is installed to tube correctly.
• After connecting line, conduct leak test and make sure that there is no leakage from connections.
When the gas leaking point is foun d, disconnect that line and replace the O-ring. Then tighten con-
nections of seal seat to the specified torque.
Connec-
tion typeO-ring
size Part 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)
SHA814E

PRECAUTIONSATC-9
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Precaution for Service of CompressorINFOID:0000000003533224
• 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 co mpressor, follow “Maintenance of Oil Quantity in Compressor”
exactly. Refer to ATC-20, "
Maintenance of Oil Quantity in Compressor".
• Keep friction surfaces between clutch and pulley clean . If the surface is contaminated with oil, wipe
it off by using a clean wast e cloth moistened with thinner.
• After compressor service operation, turn the compressor shaft by hand more than 5 turns in both
directions. This will equa lly distribute oil inside the compresso r. After the compressor is installed,
let the engine idle and oper ate the compressor for 1 hour.
• After replacing the compressor magnet clutch, ap ply voltage to the new one and check for normal
operation. Refer to ATC-155, "
Removal and Installation for Compressor Clutch".
Precaution for Service EquipmentINFOID:0000000003533225
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 fo r tester operation and tester maintenance.
VACUUM PUMP
1. Plug 2. O-ring A. Torque wrench
B. Apply oil C. Do not apply oil to threads D. NG (no good)
E. OK (okay) F. Inflated portion
WJIA1774E

ATC-10
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PRECAUTIONS
The oil contained inside the vacuum pump is not compatible with the
specified oil for HFC-134a (R-134a) A/C systems. The vent side of
the vacuum pump is exposed to atmospheric pressure so the vac-
uum pump oil may migrate out of the pump into the service hose.
This is possible when the pump is switched off after evacuation (vac-
uuming) and hose is connected to it.
To prevent this migration, use a manual valve situated near the
hose-to-pump connection, as follows.
• Usually vacuum pumps have a manual isolator valve as part of the
pump. Close this valve to isolat e the service hose from the pump.
• For pumps without an isolator, use a hose equipped with a manual shut-off valve near the pump end. Close the valve to isolate the
hose from the pump.
• If the hose has an automatic shut off valve, disconnect the hose from the pump: as long as the hose is connected, the valve is open
and lubricating oil may migrate.
Some one-way valves open when vacuum is applied and close
under a no vacuum condition. Such valves may restrict the pump's
ability to pull a deep vacuum and are not recommended.
MANIFOLD GAUGE SET
Be certain that the gauge face indicates HFC-134a (R-134a or
134a). Make sure the gauge set has 1/2 ″-16 ACME threaded con-
nections for service hoses. Confirm the set has been used only with
refrigerant HFC-134a (R-134a) along with specified oil.
SERVICE HOSES
Be certain that the service hoses display the markings described
(colored hose with black stripe). All hoses must include positive shut-
off devices (either manual or aut omatic) near the end of the hoses
opposite the manifold gauge.
SERVICE COUPLERS
RHA270D
SHA533D
RHA272D