2011 INFINITI QX56 heater

HAC-26
< SYSTEM DESCRIPTION >[AUTOMATIC AIR CONDITIONING]
SYSTEM
REAR AUTOMATIC AIR CONDITION ING SYSTEM : Door Control
INFOID:0000000006275873
DOOR MOTOR CONTROL
 LCU (Local Control Unit) is built in to each door moto r. And detects door position by PBR (Potentio Balance
Resistor).
 A/C auto amp. communicates with each LCU via comm unication line. And receives each door position feed
back signal from each LCU.
 Each LCU controls each door to the appropriate pos ition depending on the control signal from A/C auto amp.
when the door movement is complete, transmits the signal of door movement completion to A/C auto amp.
SWITCHES AND THEIR CONTROL FUNCTION
JMIIA0729GB
1. Rear blower motor 2. Rear evaporator 3. Rear air mix door
4. Rear heater core 5. Rear mode door
Recirculation air
Rear ventilator Rear A/C foot
Switch/Dial position Door position
Rear mode door Rear air mix door
AUTO switch Front A/C control
AUTO
Rear A/C control
JMIIA0744ZZ
Revision: 2010 May2011 QX56

HAC-134
< SYMPTOM DIAGNOSIS >[AUTOMATIC AIR CONDITIONING]
FRONT AUTOMATIC AIR CONDITIONING SYSTEM
Compressor does not operate. Circuit between magnet clutch and
IPDM E/R
 Magnet clutch
 IPDM E/R (A/C relay)
 Circuit between ECM and refriger- ant pressure sensor
 Refrigerant pressure sensor
 CAN communication circuit
 A/C auto amp. HAC-142, "Diagnosis Procedure"
 Insufficient cooling.
 No cool air comes out. (Air flow volume is normal.)
 Magnet clutch control system
 Drive belt slipping
 Refrigerant cycle
 Air leakage from each duct
 A/C auto amp. connection recogni-
tion signal circuit
 Temperature settin g trimmer (front)HAC-138, "FRONT AIR CONDI-
TIONER : Diagnosis Procedure"
 Insufficient heating.
 No warm air comes out. (Air flow volume is nor-
mal.)  Engine cooling system
 Heater hose
 Heater core
 Air leakage from each duct
 Temperature settin
g trimmer (front)HAC-140, "FRONT AIR CONDI-
TIONER : Diagnosis Procedure"
Noise is heard when front
air conditioning system op-
erates. During compressor
operation
Refrigerant cycle
HA-27, "
Symptom Table"
During front blower
motor operation Mixing any foreign object in front
blower motor
 Front blower motor fan breakage
 Front blower motor rotation inferiori- ty HAC-122, "Component Inspection
(Front Blower Motor)"
 Memory function does not operate.
 Setting temperature is not memorized.
 Battery power supply system of A/C
auto amp.
 A/C auto amp. HAC-110, "A/C AUTO AMP. : Diag-
nosis Procedure"
Symptom Corresponding malfunction part Reference
Revision: 2010 May2011 QX56

HAC-136
< SYMPTOM DIAGNOSIS >[AUTOMATIC AIR CONDITIONING]
REAR AUTOMATIC AIR CONDITIONING SYSTEM
 Insufficient heating.
 No warm air comes out. (Air flow volume is nor-
mal.)  Engine cooling system
 Heater hose
 Rear heater core
 Air leakage from each duct
 Temperature setting trimmer (rear)
HAC-141, "REAR AIR CONDI-
TIONER : Diagnosis Procedure"
Noise is heard when rear blower motor operates.
 Mixing any foreign object in rear
blower motor
 Rear blower motor fan breakage
 Rear blower motor rotation inferiori- ty HAC-132, "Component Inspection"
Symptom Corresponding malfunction part Reference
Revision: 2010 May2011 QX56

HAC-140
< SYMPTOM DIAGNOSIS >[AUTOMATIC AIR CONDITIONING]
INSUFFICIENT HEATING
INSUFFICIENT HEATING
FRONT AIR CONDITIONER
FRONT AIR CONDITIONER : DescriptionINFOID:0000000006275990
Symptom Insufficient heating
 No warm air comes out. (Air flow volume is normal.)
FRONT AIR CONDITIONER
: Diagnosis ProcedureINFOID:0000000006275991
NOTE:
Perform self-diagnoses with on board diagnosis and CO NSULT-III before performing symptom diagnosis. If
DTC is detected, perform the corresponding diagnosis.
1.CHECK COOLING SYSTEM
1. Check engine coolant level and check leakage. Refer to CO-8, "
Inspection".
2. Check reservoir tank cap. Refer to CO-11, "
RESERVOIR TANK CAP : Inspection".
3. Check water flow sounds of the engine coolant. Refer to CO-9, "
Refilling".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Refill engine coolant and repair or repl ace parts depending on the inspection results.
2.CHECK HEATER HOSE
Check installation of heater hose by visually or touching.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace parts depending on the inspection results.
3.CHECK FRONT HEATER CORE
1. Check temperature of inlet hose and outlet hose of front heater core.
2. Check that inlet side of front heater core is hot and t he outlet side is slightly lower than/almost equal to the
inlet side.
CAUTION:
Always perform the temperature in spection in a short period of time because the engine coolant
temperature is very hot.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace front heater core. Refer to HA-44, "
HEATER CORE : Removal and Installation".
4.CHECK AIR LEAKAGE FROM EACH DUCT
Check duct and nozzle, etc. of front air conditioning system for air leakage.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace parts depending on the inspection results.
5.CHECK SETTING OF TEMPERATURE SETTING TRIMMER (FRONT)
1. Check setting value of temperature setting trimmer (front). Refer to HAC-68, "
FRONT AUTOMATIC AIR
CONDITIONING SYSTEM : Temperature Setting Trimmer (Front)".
2. Check that temperature setting trimmer (front) is set to “ − direction”.
NOTE:
The control temperature can be set by t he temperature setting trimmer (front).
3. Set difference between the set temperature and control temperature to “0”.
Are the symptoms solved?
YES >> INSPECTION END
NO >> Replace A/C auto amp.. Refer to HAC-146, "
Removal and Installation".
REAR AIR CONDITIONER
Revision: 2010 May2011 QX56

INSUFFICIENT HEATINGHAC-141
< SYMPTOM DIAGNOSIS > [AUTOMATIC AIR CONDITIONING]
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REAR AIR CONDITIONER : DescriptionINFOID:0000000006275992
Symptom
 Insufficient heating
 No warm air comes out. (Air flow volume is normal.)
REAR AIR CONDITIONER : Diagnosis ProcedureINFOID:0000000006275993
CAUTION:
Perform the self-diagnoses with on board diagnosi s and CONSULT-III before performing symptom
diagnosis. If any malfunction result or DTC is detected, perform the corresponding diagnosis.
1.CHECK COOLING SYSTEM
1. Check engine coolant level and check leakage. Refer to CO-8, "
Inspection".
2. Check reservoir tank cap. Refer to CO-11, "
RESERVOIR TANK CAP : Inspection".
3. Check water flow sounds of the engine coolant. Refer to CO-9, "
Refilling".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Refill the engine coolant and repair or replace the parts depending on the inspection results.
2.CHECK HEATER HOSE
Check installation of heater hose by visually or touching.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace parts depending on the inspection results.
3.CHECK REAR HEATER CORE
1. Check temperature of inlet hose and outlet hose of rear heater core.
2. Check that the inlet side of rear heater core is hot and the outlet side is slightly lower than/almost equal to
the inlet side.
CAUTION:
Always perform the temperature inspection in a sh ort period of time because the engine coolant
temperature is very hot.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace rear heater core. Refer to HA-48, "
HEATER CORE : Removal and Installation".
4.CHECK AIR LEAKAGE FROM EACH DUCT
Check duct and nozzle, etc. of the rear air conditioning system for air leakage.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace parts depending on the inspection results.
5.CHECK SETTING OF TEMPERATURE SETTING TRIMMER (REAR)
1. Check setting value of temperature setting trimmer (rear). Refer to HAC-69, "
REAR AUTOMATIC AIR
CONDITIONING SYSTEM : Temperature Setting Trimmer (Rear)".
2. Check that the temperature setting trimmer is set to “ − direction”.
NOTE:
The control temperature can be set by the temperature setting trimmer (rear).
3. Set the difference between the set temperature (rear) and control temperature to “0”.
Are the symptoms solved?
YES >> INSPECTION END
NO >> Replace A/C auto amp.. Refer to HAC-146, "
Removal and Installation".
Revision: 2010 May2011 QX56

HAC-142
< SYMPTOM DIAGNOSIS >[AUTOMATIC AIR CONDITIONING]
COMPRESSOR DOSE DOT OPERATE
COMPRESSOR DOSE DOT OPERATE
DescriptionINFOID:0000000006275994
Symptom: Compressor dose not operate.
Diagnosis ProcedureINFOID:0000000006275995
NOTE:
 Perform self-diagnoses with CONSULT-III before perfo
rming symptom diagnosis. If DTC is detected, per-
form the corresponding diagnosis.
 Check that refrigerant is enclosed in cooler cycle normally. If refrigerant amount is shortage from proper
amount, perform inspection of refrigerant leakage.
1.CHECK MAGNET CLUTCH OPERATION
Check magnet clutch. Refer to HAC-126, "
Component Function Check".
Does it operate normally?
YES >> GO TO 2.
NO >> Repair or replace malfunctioning parts.
2.CHECK REFRIGERANT PRESSURE SENSOR
Check refrigerant pressure sensor. Refer to EC-520, "
Component Function Check".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace malfunctioning parts.
3.CHECK A/C AUTO AMP. OUTPUT SIGNAL
With CONSULT-III
Check “COMP REQ SIG” and “FAN REQ SIG” in “DAT A MONITOR” mode of “HVAC” using CONSULT-III.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace A/C auto amp.. Refer to HAC-146, "
Removal and Installation".
4.CHECK ECM INPUT SIGNAL
With CONSULT-III
Check “AIR COND SIG” and “HEATER FAN SW” in “D ATA MONITOR” mode of “ECM” using CONSULT-III.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Check CAN communication system. Refer to LAN-18, "
Trouble Diagnosis Flow Chart".
5.CHECK IPDM E/R INPUT SIGNAL
With CONSULT-III
1. Start engine.
Monitor item Condition Status
COMP REQ SIG A/C switch ON On
OFF Off
FAN REQ SIG Front blower motor ON On
OFF Off
Monitor item Condition Status
COMP REQ SIG A/C switch ON On
OFF Off
HEATER FAN SW Front blower motor ON On
OFF Off
Revision: 2010 May2011 QX56

DOOR MOTORHAC-153
< REMOVAL AND INSTALLATION > [AUTOMATIC AIR CONDITIONING]
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MODE DOOR MOTOR
MODE DOOR MOTOR : Re moval and InstallationINFOID:0000000006276009
REMOVAL
1. Remove instrument lower panel RH. Refer to IP-14, "Removal and Installation".
2. Remove power steering control unit bracket.
3. Remove fixing screws (A), and then remove mode door motor (1).
4. Disconnect mode door motor connector.
INSTALLATION
Install in the reverse order of removal.
AIR MIX DOOR MOTOR
AIR MIX DOOR MOTOR : Re moval and InstallationINFOID:0000000006276010
REMOVAL
Driver side
1. Remove automatic drive position control unit. Refer to ADP-136, "Removal and Installation".
2. Remove fixing screws (A), and then remove air door motor LH (1).
3. Disconnect air mix door motor connector.
Passenger side
1. Remove heater core. Refer to HA-44, "HEATER CORE : Removal and Installation".
2. Remove fixing screws, and then remove air mix door motor RH.
INSTALLATION
Install in the reverse order of removal.
INTAKE DOOR MOTOR
INTAKE DOOR MOTOR : Re moval and InstallationINFOID:0000000006276011
REMOVAL
1. Remove blower unit assembly. Refer to VTL-15, "Removal and Installation".
2. Remove fixing screws, and then remove intake door motor.
1. Rear A/C unit assembly 2. Rear mode door lever 2 3. Rear mode door lever 1
4. Rear mode door motor 5. Rear air mix door motor
JMIIA0790ZZ
JMIIA0788ZZ
Revision: 2010 May2011 QX56

MA-4
< PERIODIC MAINTENANCE >
GENERAL MAINTENANCE
PERIODIC MAINTENANCE
GENERAL MAINTENANCE
Explanation of General MaintenanceINFOID:0000000006287728
General maintenance includes those items which shoul d be checked during the normal day-to-day operation
of the vehicle. They are essential if the vehicle is to continue operating properly. The owners can perform
checks and inspections themselves or have their INFINITI dealers do them.
OUTSIDE THE VEHICLE
The maintenance items listed here should be performed fr om time to time, unless otherwise specified.
INSIDE THE VEHICLE
The maintenance items listed here should be checked on a regular basis, such as when performing periodic maintenance, cleaning the vehicle,
etc.
Item Reference page
Tires Check the pressure with a gauge often and always prior to long distance trips.
Adjust the pressure in all tires, including the spare, to the pressure specified.
Check carefully for damage, cuts or excessive wear. WT-69
Wheel nuts
When checking the tires, make sure no nuts are missing, and check for any
loose nuts. Tighten if necessary. —
Tire rotation Tires should be rotated every 12,000km (7,500 miles). If the vehicle is equipped
with different sized tires in the front and rear, tires cannot be rotated. WT-63
Tire Pressure Moni-
toring System (TPMS)
transmitter compo-
nentsReplace the TPMS transmitter grommet seal, valve core and cap when the tires
are replaced due to wear or age.
WT-66
Wheel alignment and
balanceIf the vehicle should pull to either side while driving on a straight and level road,
or if you detect uneven or abnormal tire wear, there may be a need for wheel
alignment. If the steering wheel or seat vibrates at normal highway speeds,
wheel balancing may be needed. FSU-7
RSU-6
Windshield
Clean the windshield on a regular basis. Check the windshield at least every six
months for cracks or other damage. Repair as necessary. —
Windshield wiper
blades Check for cracks or wear if they do not wipe properly. —
Doors and engine
hood Check that all doors and the engine hood operate smoothly as well as the back
door. Also make sure that all latches lock securely. Lubricate if necessary. Make
sure that the secondary latch keeps the hood from opening when the primary
latch is released.
When driving in areas using road salt or other corrosive materials, check lubri-
cation frequently. MA-34
Lamps
Make sure that the headlamps, stop lamps, tail lamps, turn signal lamps, and
other lamps are all operating properly and installed securely. Also check head-
lamp aim. Clean the headlamps on a regular basis. —
Item
Reference page
Warning lamps and
chimes Make sure that all warning lamps and chimes are operating properly. —
Windshield wiper and
washer Check that the wipers and washer operate properly and that the wipers do not
streak.
—
Windshield defroster Check that the air comes out of the defroster outlets properly and in sufficient
quantity when operating the heater or air conditioner. —
Steering wheel Check that it has the specified play. Check for changes in the steering condi-
tion, such as excessive play, hard steering or strange noises.
Free play: Less than 35 mm (1.38 in) —
Revision: 2010 May2011 QX56