2008 INFINITI QX56 service

REAR AIR CONTROL SYSTEMHAC-61
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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REAR AIR CONTROL SYSTEM
Rear Air Control System DescriptionINFOID:0000000001679804
SYSTEM DESCRIPTION
Component Parts
Rear air control system components are:
• A/C auto amp.
• Rear air control (front)
• Rear air control (rear)
• Air mix door motor (rear)
• Mode door motor (rear)
System Operation
Rear Air Control
When the REAR CTRL indicator is off the rear air cont rol (front) will control all rear blower motor speeds and
the rear temperature and mode operations. When the REAR CTRL switch is pressed (indicator on), the rear
air control (rear) will control all the rear blower motor speeds and the rear temperature and mode operations.
Rear Air Control Component Function CheckINFOID:0000000001679805
SYMPTOM:
• Temperature cannot be adjusted from the rear air controls.
• Mode cannot be adjusted from the rear air controls.
INSPECTION FLOW
1.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 2.
2.CONFIRM SYMPTOM BY PERFORMING REAR AIR CONTROL (FRONT) AIR MIX DOOR MOTOR OP-
ERATIONAL CHECK
AWIIA0197GB
Revision: March 2010 2008 QX56

MAGNET CLUTCHHAC-71
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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MAGNET CLUTCH
System DescriptionINFOID:0000000001679808
SYSTEM DESCRIPTION
The A/C auto amp. controls compressor operation based on ambient and intake temperature and a signal
from ECM.
Low Temperature Protection Control
The A/C auto amp. will turn the compressor ON or OFF as determined by a signal detected by the intake sen-
sor and the ambient sensor.
When intake air temperature is higher than the preset value, the compressor turns ON. The compressor turns
OFF when intake air temperature is lower than the pres et value. That preset value is dependent on the ambi-
ent temperature, refer to the following table.
Magnet Clutch Componen t Function CheckINFOID:0000000001679809
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING O PERATIONAL CHECK - MAGNET CLUTCH
1. Turn ignition switch ON.
2. Press the A/C switch.
3. Press vent switch ( ).
4. Display shows , A/C. Confirm that the compress or clutch engages (sound or visual inspection). (Dis-
charge air and blower speed will depend on ambient, in-vehicle and set temperatures.)
Can the symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to HAC-4, "
Operational Check (Front)".
Does another symptom exist?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to HAC-22, "
A/C Auto Amp. Self-Diagnosis".
Are any self-diagnosis codes present?
YES >> Refer to HAC-23, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 5.
5.CHECK AMBIENT SENSOR
Check and verify ambient s ensor circuit. Refer to HAC-78, "
Ambient Sensor Diagnosis Procedure".
Ambient temperature ° C (°F) Compressor ON intake temperature °C ( °F) Compressor OFF intake temperature °C ( °F)
0 (32) 5.5 (42) 5.0 (41)
10 (50) 5.5 (42) 5.0 (41)
20 (68) 5.5 (42) 5.0 (41)
30 (86) 4.0 (39) 3.5 (38)
40 (104) 3.5 (38) 3.0 (37)
50 (122) 3.5 (38) 3.0 (37)
Revision: March 2010 2008 QX56

HAC-88
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
POWER SUPPLY AND GROUND
CIRCUIT FOR CONTROLLER
POWER SUPPLY AND GROUND CIRCUIT FOR CONTROLLER
Component DescriptionINFOID:0000000001679824
COMPONENT DESCRIPTION
A/C auto amp.
The A/C auto amp. has a built-in microcomputer which processes
information sent from various sensors needed for air conditioner
operation. The air mix door motors, mode door motor, intake door
motor, defroster door motor, blower motor and compressor are then
controlled.
The A/C auto amp. is unitized with control mechanisms. When the
various switches and temperature dials are operated, data is input to
the A/C auto amp.
Self-diagnostic functions are also built into the A/C auto amp. to pro-
vide quick check of malfunctions in the auto air conditioner system.
Potentio Temperature Control (PTC)
There are two PTCs (driver and passenger) built into the A/C auto
amp. They can be set at an interval of 0.5° C (1.0°F) in the 18 °C
(60 °F) to 32° C (90°F) temperature range by rotating the temperature
dial. The set temperature is displayed.
A/C Auto Amp. Component Function CheckINFOID:0000000001679825
SYMPTOM: A/C system does not come on.
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - AUTO MODE
1. Press AUTO switch.
2. Display should indicate AUTO. Confirm that the compressor clutch engages (sound or visual inspection).
(Discharge air and blower speed will depend on am bient, in-vehicle and set temperatures.)
Can a symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.PERFORM COMPLETE OPERATIONAL CHECK
Perform a complete operational check and check for any symptoms. Refer to HAC-4, "
Operational Check
(Front)".
Can a symptom be duplicated?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.CHECK POWER AND GROUND CIRCUIT
AWIIA0573ZZ
AWIIA0211GB
Revision: March 2010 2008 QX56

INSUFFICIENT COOLINGHAC-109
< SYMPTOM DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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INSUFFICIENT COOLING
Component Function CheckINFOID:0000000001679830
SYMPTOM: Insufficient cooling
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERAT IONAL CHECK - TEMPERATURE DECREASE
1. Press the AUTO switch.
2. Turn temperature control dial (driver) counterclockwise until 18 °C (60° F) is displayed.
3. Check for cold air at discharge air outlets.
Can the symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to HAC-4, "
Operational Check (Front)".
Does another symptom exist?
YES >> Refer to HAC-108, "SymptomMatrixChart".
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis Refer to HAC-22, "
A/C Auto Amp. Self-Diagnosis".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Refer to HAC-23, "
A/C System Self-Diagnosis Code Chart".
5.CHECK DRIVE BELTS
Check compressor belt tension. Refer to EM-13, "
Checking Drive Belts".
Is the inspection result normal?
OK >> GO TO 6.
NG >> Adjust or replace compressor belt. Refer to EM-13, "
Removal and Installation".
6.CHECK AIR MIX DOOR OPERATION
Check and verify air mix door mechanism for smooth operation. Refer to HAC-31, "
Air Mix Door Motor Compo-
nent Function Check".
Does air mix door operate correctly?
YES >> GO TO 7.
NO >> Check air mix door motor circuit. Refer to HAC-32, "
Air Mix Door Motor (Driver) Diagnosis Proce-
dure" or HAC-35, "Air Mix Door Motor (Passenger) Diagnosis Procedure".
7.CHECK COOLING FAN MOTOR OPERATION
Check and verify cooling fan moto r for smooth operation. Refer to EC-395, "
Component Inspection".
Does cooling fan motor operate correctly?
YES >> GO TO 8.
NO >> Check cooling fan motor. Refer to EC-395, "
Diagnosis Procedure".
8.CHECK WATER VALVE OPERATION
Check and verify water valve for smooth operation. Refer to HAC-76, "
Description".
Does water valve operate correctly?
YES >> GO TO 9.
Revision: March 2010 2008 QX56

INSUFFICIENT HEATINGHAC-117
< SYMPTOM DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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INSUFFICIENT HEATING
Component Function CheckINFOID:0000000001679835
SYMPTOM: Insufficient heating
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERAT IONAL CHECK - TEMPERATURE INCREASE
1. Press the AUTO switch.
2. Turn the temperature control dial (driver) clockwise until 32 °C (90 °F) is displayed.
3. Check for hot air at discharge air outlets.
Can this symptom be duplicated?
YES >> GO TO 2.
NO >> Perform complete system operational check. Refer to HAC-4, "
Operational Check (Front)".
2.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 3.
3.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis. Refer to HAC-22, "
A/C Auto Amp. Self-Diagnosis".
Is the inspection results normal?
YES >> GO TO 4.
NO >> Refer to HAC-23, "
A/C System Self-Diagnosis Code Chart".
4.CHECK ENGINE COOLING SYSTEM
1. Check for proper engine coolant level. Refer to CO-10, "
Inspection".
2. Check hoses for leaks or kinks.
3. Check radiator cap. Refer to CO-10, "
Inspection".
4. Check for air in cooling system.
>> GO TO 5.
5.CHECK AIR MIX DOOR OPERATION
Check the operation of the air mix door.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Check the air mix door motor circuit. Refer to HAC-31, "
Air Mix Door Motor Component Function
Check".
6.CHECK AIR DUCTS
Check for disconnected or leaking air ducts.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair all disconnected or leaking air ducts.
7.CHECK HEATER HOSE TEMPERATURES
1. Start engine and warm it up to normal operating temperature.
2. Touch both the inlet and outlet heater hoses.
Is the inspection result normal?
YES >> Hot inlet hose and a warm outlet hose: GO TO 8.
NO >> • Inlet hose cold: GO TO 11. • Both hoses warm: GO TO 9.
8.CHECK ENGINE COOLANT SYSTEM
Check engine control temperature sensor. Refer to EC-126, "
Component Inspection".
Revision: March 2010 2008 QX56

MEMORY FUNCTION DOES NOT OPERATEHAC-121
< SYMPTOM DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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MEMORY FUNCTION DOES NOT OPERATE
Memory Function CheckINFOID:0000000001679837
SYMPTOM: Memory function does not operate.
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPER ATIONAL CHECK - MEMORY FUNCTION
1. Set the temperature to 32° C (90°F).
2. Rotate the front blower control di al (driver) to turn system OFF.
3. Turn ignition switch OFF.
4. Turn ignition switch ON.
5. Press the AUTO switch.
6. Confirm that the set temperature remains at previous temperature.
7. Rotate the front blower control dial (LH) to turn system OFF.
Can the symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.PERFORM COMPLETE OPERATIONAL CHECK
Perform a complete operational check and check for any symptoms. Refer to HAC-4, "
Operational Check
(Front)".
Can a symptom be duplicated?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to HAC-22, "
A/C Auto Amp. Self-Diagnosis".
Are any self-diagnosis codes present?
YES >> Refer to HAC-23, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 5.
5.CHECK POWER AND GROUND CIRCUIT
Check main power supply and ground circuit. Refer to HAC-88, "
A/C Auto Amp. Component Function Check".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair or replace as necessary.
6.RECHECK FOR SYMPTOMS
Perform a complete operational check for any symptoms. Refer to HAC-4, "
Operational Check (Front)".
Does another symptom exist?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> Replace A/C Auto amp. Refer to VTL-7, "
Removal and Installation".
Revision: March 2010 2008 QX56

HAC-122
< PRECAUTION >[AUTOMATIC AIR CONDITIONER]
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint Syst
em (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000004876563
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.
Working with HFC-134a (R-134a)INFOID:0000000001679839
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 vehic le and recovery tank, use Refrigerant Recovery/
Recycling Recharging 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 specified is used, compressor failure is likely to occur.
• The specified HFC-134a (R-134a) oi l rapidly absorbs 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 moisture from the atmosphere.
- When installing refrigerant co mponents to a vehicle, do not remove the caps (unseal) until just
before connecting the components. Connect all refrigerant loop 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 irrita te eyes, nose and throat.
Remove HFC-134a (R-134a) from the A/C system usin g certified service equipment meeting require-
ments of SAE J2210 [HFC-134a (R-134a) recycling equipment], or J2209 [HFC-134a (R-134a) recy-
cling equipment], If accidental system discharge occurs, ventilate work area before resuming
service. Additional health and safety information may be obtain ed from refrigerant and oil manufac-
turers.
- Do not allow A/C oil to come in contact with styrofoam parts. Damage may result.
CONTAMINATED REFRIGERANT
Revision: March 2010 2008 QX56

PRECAUTIONSHAC-123
< PRECAUTION > [AUTOMATIC AIR CONDITIONER]
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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 refrig erant into your existing service equipment. If your facility does
not have dedicated recovery equipment, you may contact a local refrigerant product retailer for available ser-
vice. 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 Cus-
tomer Affairs for further assistance.
Precaution for Service EquipmentINFOID:0000000001679840
MANIFOLD GAUGE SET
Be certain that the gauge face indicates R-134a or 134a. Make sure
the gauge set has 1/2 ″-16 ACME threaded connections 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
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. However, if an
improper connection is attempted, discharging and contamination
may occur.
SHA533D
RHA272D
Shut-off valve rotati on A/C service valve
Clockwise Open
Counterclockwise Close
RHA273D
Revision: March 2010 2008 QX56