2011 INFINITI QX56 engine

REAR A/C UNITHA-47
< REMOVAL AND INSTALLATION >
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REAR A/C UNIT ASSEMBLY
REAR A/C UNIT ASSEMBLY : Removal and InstallationINFOID:0000000006276188
REMOVAL
1. Use a refrigerant collecting equipment (for HF C-134a) to discharge the refrigerant. Refer to HA-22, "Per-
form Lubricant Return Operation".
2. Drain engine coolant from cooling system. Refer to HA-22, "
Perform Lubricant Return Operation".
3. Remove rear ventilator duct upper. Refer to VTL-12, "
REAR VENTILATOR DUCT UPPER : Removal and
Installation".
4. Remove rear ventilator duct lower. Refer to VTL-12, "
REAR VENTILATOR DUCT LOWER : Removal and
Installation".
5. Remove mounting bolt, and then disconnect rear cooler unit pipe assembly from rear cooler pipe assem-
bly.
1. Rear blower harness 2. Rear blower motor 3. Rear A/C unit case RH
4. Rear evaporator pipe assembly 5. O-ring 6. Rear expantion valve assembly
7. Rear A/C cooler pipe assembly 8. Pipe bracket 9. Grommet
10. Rear cooler pipe 11. Rear heater outlet tube assembly 12. Blind cap
13. Rear heater inlet tube assembly 14. Clamp 15. Clamp
16. Shild plate 17. Bracket 18. Rear A/C unit case LH
19. Rear evapolator 20. Drain hose 21. Rear air mix door
22. Rear heater core 23. Rear heater pipe clamp 24. Rear A/C unit upper case (front)
25. Rear mode door 26. Rear A/C unit upper case (rear) 27. Air mix door harness
28. Rear intake sensor 29. Packing
Refer to GI-4, "
Components" for symbols in the figure.
JMIIA0641GB
Revision: 2010 May2011 QX56

REAR A/C UNITHA-49
< REMOVAL AND INSTALLATION >
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5. Pull out heater core (1) from rear A/C unit assembly.
INSTALLATION
Note the following item, and install in the reverse order of removal.
NOTE:
Refer to CO-9, "
Refilling" when filling radiator with engine coolant.
EXPANSION VALVE
EXPANSION VALVE : Removal and InstallationINFOID:0000000006276192
REMOVAL
1. Remove rear A/C unit assembly. Refer to HA-47, "REAR A/C UNIT ASSEMBLY : Removal and Installa-
tion".
2. Disassembly rear A/C unit assembly.
3. Remove mounting bolts, and then disconnect rear exp ansion valve assembly from rear evaporator pipe
assembly and rear cooler pipe assembly.
INSTALLATION
Note the following items, and install in the reverse order of removal.
CAUTION:
 Replace O-rings with new ones. Then apply compressor oil to them when installing.
 Check for leakages when recharging refrigerant. Refer to HA-18, "
Leak Test".
JMIIA0685ZZ
Revision: 2010 May2011 QX56

HA-50
< SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS)
CompressorINFOID:0000000006276197
LubricantINFOID:0000000006276198
RefrigerantINFOID:0000000006276199
Engine Idling SpeedINFOID:0000000006276200
Refer to EC-538, "Idle Speed".
Belt TensionINFOID:0000000006276201
Refer to EM-20, "TensionAdjustment".
Model VALEO THERMAL SYSTEMS JAPAN make
DSK-17D
Ty p e Fixation displacement swash plate
Displacement
cm
3 (cu in)/rev Maximum 175 (10.7)
Direction of rotation Clockwise (viewed from clutch)
Drive belt Poly V
Disc to pulley clearance
mm (in) Standard 0.3 – 0.6 (0.012 – 0.024)
Name
UV Luminaus Oil Type S (DH-PS)
Capacity
m (Imp fl oz) Total in system 210 (7.1)
Compressor (service part) charging
amount
210 (7.1)
Ty p e
HFC-134a (R-134a)
Capacity
kg (lb) 1.05 (2.32)
Revision: 2010 May2011 QX56

PRECAUTIONSHAC-5
< PRECAUTION > [AUTOMATIC AIR CONDITIONING]
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006275847
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 whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision that would result in air ba g 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 AIR BAG”.
 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.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the
ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
 When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minutes before performing any service.
Revision: 2010 May2011 QX56

HAC-6
< SYSTEM DESCRIPTION >[AUTOMATIC AIR CONDITIONING]
COMPONENT PARTS
SYSTEM DESCRIPTION
COMPONENT PARTS
FRONT AUTOMATIC AIR CONDITIONING SYSTEM
FRONT AUTOMATIC AIR CONDITIONING
SYSTEM : Component Parts Location
INFOID:0000000006275848
1. Preset switch 2. Engine coolant temperature sensor
Refer to EC-16, "
Component Parts
Location". 3. IPDM E/R
Refer to PCS-4, "
Component Parts
Location".
4. ECM Refer to EC-16, "
Component Parts
Location"
5. Refrigerant pressure sensor 6. Ambient sensor
7. Magnet clutch 8. AV control unit Refer to AV- 9 , "
Component Parts Lo-
cation". 9. Combination meter
Refer to MWI-6, "
METER SYSTEM :
Component Parts Location".
10. Sunload sensor 11. Front display 12. Upper ventilator door motor
JMIIA0812ZZ
Revision: 2010 May2011 QX56

COMPONENT PARTSHAC-7
< SYSTEM DESCRIPTION > [AUTOMATIC AIR CONDITIONING]
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FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Component Description
INFOID:0000000006275849
13. Aspirator 14. Front air mix door motor (Driver side) 15. Intake sensor
16. Front mode door motor 17. Front air mix door motor (Passenger
side)18. Intake door motor
19. Front blower motor 20. A/C auto amp. 21. Front in-vehicle sensor
A. Left side of heater & cooling unit as- sembly B. Right side of heater & cooling unit as-
sembly C. Back side of blower unit assembly
D. Cluster lid C is removed E. Ins trument lower panel LH is re-
moved
Component Description
Ambient sensor Ambient sensor measures ambient air temperature. The sensor uses a
thermistor which is sensitive to the change in temperature. The electrical
resistance of the thermistor decreases as temperature increases.
AV c o n t r o l u n i t AV control unit transmits front A/C control operation signal to A/C auto amp.
via CAN communication line.
A/C auto amp. A/C auto amp. controls front automatic air conditioning system by inputting
and calculating signals from each sensor and each switch. A/C auto amp.
has self-diagnosis function. Diagnosis of front automatic air conditioning
system can be performed quickly.
Blower unit Front blower motor Refer to
HAC-12
.
Intake door motor The LCU (Local Control Unit) is installed to intake door motor so as to per-
form the multiplex commu
nication control (LIN).
Refer to HAC-18, "
FRONT AUTOMATIC AIR CONDITIONING SYSTEM :
Door Control".
Combination meter Combination meter transmits vehicle speed signal to A/C auto amp. via
CAN communication line.
ECM ECM controls compressor according to status of engine and refrigerant.
ECM transmits engine coolant temperature signal to A/C auto amp. via
CAN communication line.
Engine coolant temperature sensor Engine coolant temperature sensor measures engine coolant temperature.
The sensor uses a thermistor which is sensitive to the change in tempera-
ture. The electrical resistance of the thermistor decreases as temperature
increases.
Front display Front display indicates operation status of front automatic air conditioning
system.
Front in-vehicle sensor Front in-vehicle sensor measures temperature of intake air that flows
through aspirator to passenger room. The sensor uses a thermistor which
is sensitive to the change in temperature. The electrical resistance of the
thermistor decreases as temperature increases.
Revision: 2010 May2011 QX56

COMPONENT PARTSHAC-9
< SYSTEM DESCRIPTION > [AUTOMATIC AIR CONDITIONING]
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REAR AUTOMATIC AIR CONDITIONING SY STEM : Component Parts Location
INFOID:0000000006275850
1. Rear A/C control 2. Preset switch 3. Engine coolant temperature sensor
Refer to EC-16, "
Component Parts
Location".
4. ECM Refer to EC-16, "
Component Parts
Location". 5. Ambient sensor 6. AV control unit
Refer to AV- 9 , "
Component Parts Lo-
cation".
7. Combination meter Refer to MWI-6, "
METER SYSTEM :
Component Parts Location". 8. Sunload sensor 9. Front display
10. Rear mode door motor 11. Rear air mix door motor 12. Rear in-vehicle sensor
13. Rear blower motor 14. Rear A/C solenoid valve 15. Rear A/C relay
16. Intake sensor 17. A/C auto amp.
A. Right side of rear A/C unit assembly B. Left side of rear A/C unit assembly C. Back side of engine room (RH)
D. Left side of heater & cooling unit as- sembly E. Cluster lid C is removed
JMIIA0813ZZ
Revision: 2010 May2011 QX56

HAC-10
< SYSTEM DESCRIPTION >[AUTOMATIC AIR CONDITIONING]
COMPONENT PARTS
REAR AUTOMATIC AIR CONDITIONING SYSTEM : Component Description
INFOID:0000000006275851
ACCS (ADVANCED CLIMATE CONTROL SYSTEM)
Component Description
Ambient sensor Ambient sensor measures ambient air temperature. The sensor uses a
thermistor which is sensitive to the change in temperature. The electrical
resistance of the thermistor decreases as temperature increases.
AV c o n t r o l u n i t AV control unit transmits front A/C control operation signal to A/C auto amp.
via CAN communication line.
A/C auto amp. A/C auto amp. controls rear automatic air conditioning system by inputting
and calculating signals from each sensor and each switch. A/C auto amp.
has self-diagnosis function. Diagnosis of rear automatic air conditioning
system can be performed quickly.
Combination meter Combination meter transmits vehicle speed signal to A/C auto amp. via
CAN communication line.
ECM ECM transmits engine coolant temperature signal to A/C auto amp. via
CAN communication line.
Engine coolant temperature sensor Engine coolant temperature sensor measures engine coolant temperature.
The sensor uses a thermistor which is sensitive to the change in tempera-
ture. The electrical resistance of the thermistor decreases as temperature
increases.
Front display Front display indicates operation status of rear automatic air conditioning
system.
Heater & cooling unit
assembly Intake sensor Intake sensor measures temperature of front evaporator fin temperature.
The sensor uses a thermistor which is sensitive to the change in tempera-
ture. The electrical resistance of the thermistor decreases as temperature
increases.
Preset switch Preset switch is integrated with front A/C control and AV operation switch.
Front A/C control operation signal is transmitted from preset switch to AV
control unit via communication line.
Rear A/C control The operation of the rear A/C control is communicated with the A/C auto
amp. via communication line.
Rear A/C relay Power is supplied to the rear A/C solenoid valve through rear A/C relay with
A/C auto amp. control.
Rear A/C unit assem-
bly Rear air mix door motor
The LCU (Local Contro
l Unit) is installed to rear air mix door motor so as to
perform the multiplex communication control (LIN).
Refer to HAC-26, "
REAR AUTOMATIC AIR CONDITIONING SYSTEM :
Door Control".
Rear A/C solenoid valve Rear A/C solenoid valve operates by power supply from rear A/C relay and
opens refrigerant line to rear evaporator.
Rear blower motor Refer to HAC-13
.
Rear in-vehicle sensor Rear in-vehicle sensor measures temperature of intake air that flows
through rear blower motor to passenger room. The sensor uses a ther-
mistor which is sensitive to the change in temperature. The electrical resis-
tance of the thermistor decreases as temperature increases.
Rear mode door motor The LCU (Local Control Unit) is installed to rear mode door motor so as to
perform the multiplex communication control (LIN).
Refer to
HAC-26, "
REAR AUTOMATIC AIR CONDITIONING SYSTEM :
Door Control".
Sunload sensor Sunload sensor measures sunload amount. This sensor is a dual system
so that sunload for driver side and passenger side are measured separate-
ly. This sensor converts sunload amount to voltage signal by photodiode
and transmits to A/C auto amp..
Revision: 2010 May2011 QX56