2008 INFINITI QX56 service

VTL-1
VENTILATION, HEATER & AIR CONDITIONER
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CONTENTS
VENTILATION SYSTEM
PRECAUTION ....... ........................................2
PRECAUTIONS .............................................. .....2
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
2
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ............................... ......
2
Precaution for Working with HFC-134a (R-134a) ......3
Precaution for Procedure without Cowl Top Cover ......3
PREPARATION ............................................4
PREPARATION .............................................. .....4
Commercial Service Tool .................................... ......4
FUNCTION DIAGNOSIS ...............................5
IN-CABIN MICROFILTER .............................. .....5
Description .......................................................... ......5
ON-VEHICLE MAINTENANCE .....................6
IN-CABIN MICROFILTER .............................. .....6
Removal and Installation ...........................................6
ON-VEHICLE REPAIR .... ..............................7
CONTROL UNIT ..................................................7
Removal and Installation ...........................................7
IN-VEHICLE SENSOR ................................... .....9
Removal and Installation ...........................................9
OPTICAL SENSOR ........................................ ....10
Removal and Installation .........................................10
INTAKE SENSOR ..............................................11
Removal and Installation .........................................11
BLOWER MOTOR .......................................... ....12
Component .......................................................... ....12
Removal and Installation ..................................... ....12
IN-CABIN MICROFILTER .................................14
Removal and Installation .........................................14
HEATER & COOLING UNIT ASSEMBLY ........15
Component ..............................................................15
Removal and Installation .........................................16
HEATER CORE .................................................18
Component ..............................................................18
Removal and Installation .........................................19
DEFROSTER DOOR MOTOR ..........................21
Removal and Installation .........................................21
INTAKE DOOR MOTOR ...................................22
Removal and Installation .........................................22
MODE DOOR MOTOR ......................................23
Components ............................................................23
Removal and Installation .........................................24
AIR MIX DOOR MOTOR ...................................25
Component ..............................................................25
Removal and Installation .........................................26
VARIABLE BLOWER CONTROL .....................28
Components ............................................................28
Removal and Installation .........................................29
DUCTS AND GRILLES .....................................30
Component ..............................................................30
Removal and Installation .........................................33
REFRIGERANT LINES .....................................35
Removal and Installation for Front Evaporator ........35
Removal and Installation for Rear Evaporator .........36
Removal and Installation for Rear Expansion
Valve ........................................................................
37
Revision: March 2010 2008 QX56

VTL-2
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000004884177
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 severity 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 SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inopera tive, 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 unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harn esses can be identified 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 Airbag Diagnosis Sensor Unit or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or electri c 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 minu tes before performing any service.
Precaution Necessary for Steering W heel Rotation After Battery Disconnect
INFOID:0000000004884178
NOTE:
• This Procedure is applied only to models with Intelligent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
• Remove and install all control units after disconnecting both battery cables with the ignition knob in the
″LOCK ″ position.
• Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS, an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery pow er is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be rotated.
4. Perform the necessary repair operation.
Revision: March 2010 2008 QX56

PRECAUTIONSVTL-3
< PRECAUTION >
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5. When the repair work is completed, return the ignition switch to the ″LOCK ″ position before connecting
the battery cables. (At this time, the steering lock mechanism will engage.)
6. Perform a self-diagnosis check of al l control units using CONSULT-III.
Precaution for Working with HFC-134a (R-134a)INFOID:0000000001516598
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 HA-4, "
Contaminated Refrigerant". To deter-
mine the purity of HFC-134a (R-134a) in the vehicle and recovery tank, use recovery/recycling equip-
ment 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 specified 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 r eseal 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.
Precaution for Procedur e without Cowl Top CoverINFOID:0000000001516599
When performing the procedure after removing cowl top cover, cover
the lower end of windshield with urethane, etc.
PIIB3706J
Revision: March 2010 2008 QX56

VTL-4
< PREPARATION >
PREPARATION
PREPARATION
PREPARATION
Commercial Service ToolINFOID:0000000001516600
Tool nameDescription
Power tool Loosening bolts and nuts
PBIC0190E
Revision: March 2010 2008 QX56

HEATER & COOLING UNIT ASSEMBLYVTL-15
< ON-VEHICLE REPAIR >
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HEATER & COOLING UNIT ASSEMBLY
ComponentINFOID:0000000001516610
Front A/C System
WJIA1578E
1. High-pressure service valve 2 . Grommet 3. High-pressure pipe
4. Refrigerant pressure sensor 5. Condenser 6. Compressor shaft seal
Revision: March 2010 2008 QX56

VTL-16
< ON-VEHICLE REPAIR >
HEATER & COOLING UNIT ASSEMBLY
Rear A/C System
NOTE:
Refer to HA-5, "
Precaution for Refrigerant Connection".
Removal and InstallationINFOID:0000000001516611
FRONT HEATER AND COOLING UNIT ASSEMBLY
Removal
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
AWIIA0134GB
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 motor6. Underfloor rear A/C pipes
7. Underfloor rear heater core pipes A. Bolt torque specification B. Leak checking order (l - r)
C. Tightening torque D. Wrench sizeE. O-ring size
⇐ Front
NOTE: The O-ring size 8 is the high-side and the O-ring size 16 is the low-side.
Revision: March 2010 2008 QX56

HEATER & COOLING UNIT ASSEMBLYVTL-17
< ON-VEHICLE REPAIR >
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1. Move the two front seats to the rear most position on the seat track.
2. Disconnect the battery negative terminal and battery positive terminal.
3. Discharge the refrigerant from the A/C system. Refer to HA-20, "
HFC-134a (R-134a) Service Procedure".
4. Drain the coolant from the engine cooling system. Refer to CO-11, "
Changing Engine Coolant".
5. Disconnect the front heater hoses from the front heater core.
6. Disconnect the high/low pressure pipes from the front expansion valve.
7. Remove the instrument panel and console panel. Refer to IP-12, "
Removal and Installation".
8. Remove the steering column. Refer to ST-20, "
Removal and Installation".
9. Disconnect the instrument panel wire harness at t he RH and LH in-line connector brackets, and the fuse
block (J/B) electrical connectors. Refer to PG-9, "
Wiring Diagram — Battery Power Supply —".
10. Disconnect the steering member from each side of the vehicle body.
11. Remove the front heater and cooling unit assembly with it attached to the steering member, from the vehi- cle.
CAUTION:
Use care not to damage the seats and interior trim panels when removing the front heater and
cooling unit assembly with it at tached to the steering member.
12. Remove the front heater and cooling uni t assembly from the steering member.
Installation
Installation is in the reverse order of removal.
CAUTION:
• Replace the O-ring of the low-pressure pipe and high-pressure pipe with a new one, and apply com-
pressor oil to it when installing it.
• After charging the refrigerant, check for leaks.
NOTE:
• Fill the engine cooling system with the specified coolant mixture. Refer to CO-11, "
Changing Engine Cool-
ant".
• Recharge the A/C system. Refer to HA-20, "
HFC-134a (R-134a) Service Procedure".
REAR HEATER AND COOLING UNIT ASSEMBLY
Removal
1. Discharge the refrigerant from the A/C system. Refer to HA-20, "HFC-134a (R-134a) Service Procedure".
2. Drain the coolant from the engine cooling system. Refer to CO-11, "
Changing Engine Coolant".
3. Remove the luggage side finisher lower RH. Refer to INT-19, "
Removal and Installation".
4. Disconnect the rear heater core hoses from the rear heater core.
5. Disconnect the rear A/C pipes from the rear expansion valve.
6. Disconnect the following electrical connectors: • Rear blower motor
• Rear variable blower control
• Rear air mix door motor
7. Disconnect the ducts from the rear heater and cooling unit assembly.
8. Remove the rear heater and cooling unit assembly.
Installation
Installation is in the reverse order of removal.
CAUTION:
• Replace the O-ring of the low-pressure pipe and high-pressure pipe with a new one, and apply com- pressor oil to it when installing it.
• After charging the refrigerant, check for leaks.
NOTE:
• Fill the engine cooling system with the specified coolant mixture. Refer to CO-11, "
Changing Engine Cool-
ant".
• Recharge the A/C system. Refer to HA-20, "
HFC-134a (R-134a) Service Procedure".
Revision: March 2010 2008 QX56

REFRIGERANT LINESVTL-37
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REMOVAL
1. Remove the rear heater and cooling unit assembly from the vehicle. Refer to VTL-16, "Removal and
Installation".
2. Remove the blower motor.
3. Remove the variable blower control.
4. Remove the air mix door motor.
5. Remove the mode door motor.
6. Remove the rear duct and mode door assembly. Refer to VTL-33, "
Removal and Installation".
7. Disassemble the rear heater and cooling unit assembly to remove the evaporator.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
• Replace the O-rings on the rear A/C pipes with new ones. Apply compressor oil to the O-rings when installing them.
• After charging the refrigerant, check for leaks.
Removal and Installation for Rear Expansion ValveINFOID:0000000001516626
REMOVAL
1. Discharge the refrigerant. Refer to HA-20, "HFC-134a (R-134a) Service Procedure".
2. Remove the luggage side finisher lower (RH). Refer to INT-19, "
Removal and Installation".
3. Disconnect the A/C refrigerant pi pes from the expansion valve.
CAUTION:
Cap or wrap the A/C refrigerant pipe ends with a suitable material such as vinyl tape to avoid the
entry of air and contaminants.
4. Remove the expansion valve.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
• Replace the O-rings on the A/C refrigerant pipes with new ones, th en apply compressor oil to them
when installing them.
• After charging the refrigerant, check for leaks. Expansion valve bolts : 4 N·m (0.41 kg-m, 35 in-lb)
A/C refrigerant pipe to expansion valve bolt : Refer to HA-29, "
Component".
Revision: March 2010
2008 QX56