2011 INFINITI QX56 engine

HA-6
< PRECAUTION >
PRECAUTIONS
 Turn the compressor shaft by hand more than five turns in both directions after compressor service
operation. This distributes equall y lubricant inside the compressor. Let the engine idle and operate
the compressor for one hour after the compressor is installed.
 Apply voltage to the new one and check for norma l operation after replacing the compressor magnet
clutch.
LEAK DETECTION DYE
CAUTION:
 The A/C system contains a fluorescent leak detect ion dye used for locating refrigerant leakages. An
ultraviolet (UV) lamp is required to il luminate the dye when inspecting for leakages.
 Wear always fluorescence enhancing UV safety goggles to protect eyes and enhance the visibility of
the fluorescent dye.
 The fluorescent dye leak detector is not a replacem ent for an electrical leak detector. The fluorescent
dye leak detector should be used in conjunction with an electrical leak detector to pin-point refriger-
ant leakages.
 Read and follow all manufacture’ s operating instructions and precau tions prior to performing the
work for the purpose of safet y and customer’s satisfaction.
 A compressor shaft seal should not necessarily be repaired because of dye seepage. The compres-
sor shaft seal should only be repaired after conf irming the leakage with an electrical leak detector.
 Remove always any remaining dye from the leakage area after repairs are completed to avoid a mis-
diagnosis during a future service.
 Never allow dye to come into contact with painted body panels or interior components. Clean imme-
diately with the approved dye cl eaner if dye is spilled. Fluorescent dye left on a surface for an
extended period of time cannot be removed.
 Never spray the fluorescent dye cleaning agent on hot surfaces (eng ine exhaust manifold, etc.).
 Never 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. Never use
HFC-134a (R-134a) leak detection dye in CFC-12 (R- 12) A/C system, or CFC-12 (R-12) leak detection
dye in HFC-134a (R-134a) A/C system, or A/C system damage may result.
 The fluorescent properties of the dye remains fo r three or more years unless a compressor malfunc-
tion occurs.
NOTE:
Identification
 Vehicles with factory installed fluorescent dye have a green label.
 Vehicles without factory installed fluorescent dye have a blue label.
Service EquipmentINFOID:0000000006276140
RECOVERY/RECYCLING RECHARGING EQUIPMENT
Be certain to follow the manufacturer’s instructions for machine operation and machine maintenance. Never
introduce any refrigerant other than that specified into the machine.
ELECTRICAL LEAK DETECTOR
Be certain to follow the manufacturer’s instruct ions for tester operation and tester maintenance.
VACUUM PUMP
Revision: 2010 May2011 QX56

SYSTEMHA-15
< SYSTEM DESCRIPTION >
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The refrigerant from the compressor, frows the condens er with liquid tank, the evaporator, and returns to the
compressor. The refrigerant evaporation in the evaporator is controlled by an expansion valve.
Freeze Protection
Automatic air conditioner When intake sensor detects that evaporator surface temperature is 2.5°C (37 °F) or less, A/C auto amp.
requests BCM to turn the compressor OFF.
 BCM requests ECM to turn the compressor to OFF by the signal from A/C auto amp., and ECM makes A/C
relay to OFF, and stops the compressor.
REFRIGERANT SYSTEM PROTECTION
Refrigerant Pressure Sensor
 The refrigerant system is protected against excessively high- or low-pressures by the refrigerant pressure
sensor, installed at the condenser exit. The refrigerant pressure sensor detects the pressure inside the
refrigerant line and sends the voltage signal to the ECM if the system pressure rises above, or falls below
the specifications.
 ECM turns the A/C relay to OFF and stops the compress or when the high-pressure side detected by refriger-
ant pressure sensor is following conditions;
- Approximately 3,120 kPa (31.8 kg/cm
2, 452 psi) or more (Engine speed is less than 1,500 rpm.)
- Approximately 2,740 kPa (27.9 kg/cm
2, 397 psi) or more (Engine speed is 1,500 rpm or more.)
- Approximately 140 kPa (1.4 kg/cm
2, 20 psi) or less
Pressure Relief Valve
The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor.
The release port on the pressure relief valve automatical ly opens and releases refrigerant into the atmosphere
when the pressure of refrigerant in the system incr eases to an unusual level [more than 3,800 kPa (38.8 kg/
cm
2, 551 psi)].
Revision: 2010 May2011 QX56

REFRIGERANTHA-19
< BASIC INSPECTION >
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Never look directly into UV lamp light source.
NOTE:
 For continuous operating time of UV lamp, fo llow the manufacturer operating instructions.
 Illuminate piping joints from different angles us ing UV lamp and check that there is no leakage.
 Use a mirror in area that is difficult to see to check refrigerant leakage.
 Refrigerant leakage from evaporator can be detected by soaking cotton swab or a similar material with
drain hose water and illuminating it using UV lamp.
 Dust, dirt, and packing materials adhesive used for condenser, evaporator, and other locations may flu- oresce. Be careful not to misidentify leakage.
5. Repair or replace parts where refrigerant leak age occurs and wipe off fluorescent leak detection dye.
NOTE:
Completely wipe off fluorescent leak detection dy e from gaps between parts, screw threads, and others
using a cotton swab or similar materials.
6. Use a UV lamp to check that no fluorescent leak detection dye remains after finishing work. WARNING:
Never look directly into UV lamp light source.
NOTE:
 For continuous operating time of UV lamp, fo llow the manufacturer operating instructions.
 Dust, dirt, and packing materials adhesive used for condenser, evaporator, and other locations may flu-
oresce. Be careful not to misidentify leakage.
CHECK REFRIGERANT LEAKAGE USIN G ELECTRICAL LEAK DETECTOR
WARNING:
Never check refrigerant leakage while the engine is running.
CAUTION:
Be careful of the following items so that in accurate checks or misidentifications are avoided.
 Never allow refrigerant vapor, shop chemical vapors, cigarette smoke, or others around the vehicle.
 Always check refrigerant leakage in a low air flow environment so that refrigerant may not disperse
when leakage occurs.
1. Stop the engine.
2. Connect recovery/recycling/recharging equipment or manifold gauge set to A/C service valve.
3. Check that A/C refrigerant pressure is 345 kPa (3.52 kg/cm
2, 50 psi) or more when temperature is 16 °C
(61 °F) or more. When pressure is lower than the spec ified value, recycle refrigerant completely and fill
refrigerant to the specified level.
NOTE:
Leakages may not be detected if A/C refri gerant pressure is 345 kPa (3.52 kg/cm
2, 50 psi) or less when
temperature is less than 16 °C (61 °F).
4. Clean area where refrigerant leakage check is per formed, and check refrigerant leakage along all sur-
faces of pipe connections and A/C system com ponents using electrical leak detector probe.
CAUTION:
 Continue checking when a leakage is found. Always continue and complete checking along all
pipe connections and A/C system co mponents for additional leakage.
 When a leakage is detected, clean leakage area using compressed air and check again.
 When checking leakage of cooling unit inside, al ways clean inside of drain hose so that the
probe surface may not be exposed to water or dirt.
NOTE:
 Always check leakage starting from high-pressure side and continue to low-pressure side.
 When checking leakage of cooling unit inside, operate blower fan motor for 15 minutes or more at the maximum fan speed while the engine is stopped, and then insert electrical leak detector probe into drain
hose and hold for 10 minutes or more.
 When disconnecting shut-off valve that is connected to A/C service valve, always evacuate remaining
refrigerant so that misidentification can be avoided.
5. Repair or replace parts where refrigerant leak age is detected. (Leakage is detected but leakage area is
unknown. GO TO 6.)
6. Start the engine and set A/C control in the following conditions.  A/C switch ON
 Air flow: VENT (ventilation)
 Intake door position: Recirculation
Revision: 2010 May2011 QX56

HA-20
< BASIC INSPECTION >
REFRIGERANT
 Temperature setting: Full cold
 Fan speed: Maximum speed set
7. Run the engine at approximately 1,500 rpm for 2 minutes or more.
8. Stop the engine. Check again for refrigerant leakage. GO TO 4.
WARNING:
Be careful not to get burned when the engine is hot.
NOTE:
 Start refrigerant leakage check immediately after the engine is stopped.
 When refrigerant circulation is stopped, pressure on the low-
pressure side rises gradually, and after this, pressure on the
high-pressure side falls gradually.
 The higher the pressure is, the easier it is to find the refriger-
ant leakage.
Recycle RefrigerantINFOID:0000000006276151
WARNING:
 Always use HFC-134a for A/C refrigerant. If CFC-12 is accidentally charged, compressor is damaged
due to insufficient lubrication.
 Always observe and follow precaution s described on refrigerant container. Incorrect handling may
result in an explosion of refrigerant co ntainer, frostbite, or the loss of eyesight.
 Never breathe A/C refrigerant and lubricant vapor or mist. Exposure may irritate eyes, nose, or
throat.
 Never allow HFC-134a to be exposed to an open flam e or others because it generates poisonous gas
when in contact with high temperature ob jects. Keep workshop well ventilated.
1. Perform lubricant return operation. Refer to HA-22, "
Perform Lubricant Return Operation". (If refrigerant or
lubricant leakage is detected in a large am ount, omit this step, and then GO TO 2.)
CAUTION:
Never perform lubricant return op eration if a large amount of refrigerant or lubricant leakage is
detected.
2. Check gauge pressure readings of recovery/recyc ling/recharging equipment. When remaining pressure
exists, recycle refrigerant from high-pressure hose and low-pressure hose.
NOTE:
Follow manufacturer instructions for the handling or maintenance of the equipment. Never fill the equip-
ment with non-specified refrigerant.
3. Remove A/C service valve cap from the vehicle.
4. Connect recovery/recycling/rechargi ng equipment to A/C service valve.
5. Operate recovery/recycling/recharging equipm ent, and recycle refrigerant from the vehicle.
6. Evacuate air for 10 minutes or more to remove any remaining refrigerant integrated to compressor lubri-
cant, etc.
7. Refrigerant recycle operation is complete.
Charge RefrigerantINFOID:0000000006276152
WARNING:
 Always use HFC-134a for A/C refrigerant. If CFC-12 is accidentally charged, compressor is damaged
due to insufficient lubrication.
 Always observe and follow precaution s described on refrigerant container. Incorrect handling may
result in an explosion of refrigerant co ntainer, frostbite, or the loss of eyesight.
 Never breathe A/C refrigerant and lubricant vapor or mist. Exposure my irritate eyes, nose, or throat.
 Never allow HFC-134a to be exposed to an open flam e or others because it generates poisonous gas
when in contact with high temperature ob jects. Keep workshop well ventilated.
1. Connect recovery/recycling/recharging equipment to the A/C service valve.
SHA839E
Revision: 2010 May2011 QX56

HA-22
< BASIC INSPECTION >
LUBRICANT
LUBRICANT
DescriptionINFOID:0000000006276153
MAINTENANCE OF LUBRICANT LEVEL
The compressor lubricant is circulating in the system together with the refrigerant. It is necessary to fill com-
pressor with lubricant when replacing A/C system pa rts or when a large amount of refrigerant leakage is
detected. It is important to always maintain lubricant level within the specified level. Otherwise, the following
conditions may occur.
 Insufficient lubricant amount: Stuck compressor
 Excessive lubricant amount: Insufficient cooling (caused by insufficient heat exchange)
InspectionINFOID:0000000006276154
If a compressor is malfunctioning (internal noise, insufficient cooling), check the compressor oil.
1.COMPRESSOR OIL JUDGMENT
1. Remove the compressor. Refer to HA-30, "
Exploded View".
2. Sample a compressor oil and judge on the figure.
Judgement result 1>>Replace compressor only.
Judgement result 2>>Replace compressor and liquid tank.
Perform Lubricant Return OperationINFOID:0000000006276155
CAUTION:
If a large amount of refrigerant or lubricant leakag e is detected, never perform lubricant return opera-
tion.
1. Start the engine and set to the following conditions.
 Engine speed: Idling to 1,200 rpm
 A/C switch: ON
 Fan speed: Maximum speed set
 Intake door position: Recirculation
 Temperature setting: Full cold
2. Perform lubricant return operation for approximately 10 minutes.
3. Stop the engine.
4. Lubricant return operation is complete.
Lubricant Adjusting Procedure for Comp onents Replacement Except Compressor
INFOID:0000000006276156
Fill with lubricant for the amount that is calculated according to the following conditions.
Example: Lubricant amount to be added when replacing evapor ator and liquid tank [m (Imp fl oz.)] = 35 (1.2)
+ 20 (0.7) + 5 (0.2) + α
Name A/C System Oil Type S
JSIIA0927GB
Revision: 2010 May2011 QX56

PERFORMANCE TESTHA-25
< BASIC INSPECTION >
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PERFORMANCE TEST
InspectionINFOID:0000000006276158
INSPECTION PROCEDURE
1. Connect recovery/recycling/recharging equipment (for HFC-134a) or manifold gauge.
2. Start the engine, and set to the following condition.
Test condition
3. Maintain test condition until A/C system becomes stable. (Approximately 10 minutes)
4. Check that test results of “recirculating-to-disc harge air temperature” and “ambient air temperature-to-
operating pressure” are within the specified value.
5. When test results are within the specified value, inspection is complete. If any of test result is out of the specified value, perform diagnosis by gauge pressure. Refer to HA-27,
"Symptom Table".
RECIRCULATING-TO-DISCHARGE AIR TEMPERATURE TABLE
FRONT
REAR
Surrounding condition Indoors or in the shade (in a well-ventilated place)
Vehicle conditionDoor Closed
Door glass Full open
Hood Open
Engine speed Idle speed
A/C condition (front/rear) Temperature control switch or dial Full cold
A/C switch ON
Air outlet VENT (ventilation)
Intake door position Recirculation
Fan speed Maximum speed set
Inside air (Recirculating air) at blower assembly inlet
Discharge air temperature from center ventilator
°C ( °F)
Relative humidity
% Air temperature
°C ( °F)
50 – 60 20 (68) 6.8 - 8.8 (44 - 48)
25 (77) 10.4 -
12.9 (51 - 55)
30 (86) 13.9 - 16.9 (57 - 63)
35 (95) 17.3 - 20.8 (63 - 70)
60 – 70 20 (68) 8.8 - 10.8 (48 - 52)
25 (77) 12.9 -
15.4 (55 - 60)
30 (86) 16.9 - 19.9 (63 - 68)
35 (95) 20.8 - 24.3 (70 - 76)
Inside air (Recirculating air) at blower assembly inlet
Discharge air temperature from rear ventilator grille A RH*
°C ( °F)
Relative humidity
% Air temperature
°C ( °F)
50 – 60 20 (68) 11.4 -
13.4 (53 - 56)
25 (77) 15.8 - 18.3 (60 - 65)
30 (86) 20.9 - 23.9 (70 - 75)
35 (95) 25.9 - 29.4 (79 - 85)
Revision: 2010 May2011 QX56

HA-36
< REMOVAL AND INSTALLATION >
COOLER PIPE AND HOSE
9. Partly remove rear half of front fender protector RH. Refer to EXT-23, "FENDER PROTECTOR : Exploded
View".
10. Remove high-pressure pipe.
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".
LOW-PRESSURE PIPE
LOW-PRESSURE PIPE : Removal and InstallationINFOID:0000000006276176
CAUTION:
Perform lubricant return operation before each re frigeration system disassembly. However, if a large
amount of refrigerant or lubrican t is detected, never perform lubricant return operation. Refer to HA-
22, "Perform Lubricant Return Operation".
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 CO-8, "
Draining".
3. Remove engine cover. Refer to EM-25, "
Removal and Installation".
4. Remove mouting bolt (A) and fixing pawls, and then remove relay box (1).
5. Remove mounting bolts (A), and then remove relay box bracket(1).
6. Remove front water outlet tube assembly mounting nut.
7. Remove mounting nuts, and then disconnec t mounting bracket from the vhiecle.
8. Remove mounting bolt, and then disconnect low-pressure pipe from low-pressure flexible hose. CAUTION:
Cap or wrap the joint of the A/C piping with suitab le material such as vinyl tape to avoid the entry
of air.
9. Remove mounting bolt, and then disconnect low-pressure pipe from expansion valve. CAUTION:
: Pawl
JMIIA0798ZZ
JMIIA0799ZZ
Revision: 2010 May2011 QX56

A/C UNIT ASSEMBLYHA-43
< REMOVAL AND INSTALLATION >
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Perform lubricant return operati on before each refrigeration system disassembly. However, if a large
amount of refrigerant or lubricant is detected, n ever perform lubricant return operation. Refer to HA-
22, "Perform Lubricant Return Operation".
REMOVAL
1. Use a refrigerant collecting equipment (for HF C-134a) to discharge the refrigerant. Refer to HA-20, "Recy-
cle Refrigerant". (If equipped)
2. Drain engine coolant from cooling system. Refer to CO-8, "
Draining".
3. Remove clamps, and then disconnect front heater outlet hose from heater pipe.
CAUTION:
 Some coolant may spill when heater hoses are disconnected.
 Close off the coolant inlet and outlet on the heater core (2 locations) with shop cloths.
4. Remove mounting bolt, and then disconnect low-pressure pipe and high-pressure pipe from expansion valve.
CAUTION:
Cap or wrap the joint of the A/C piping and expan sion valve with suitable material such as vinyl
tape to avoid the entry of air.
5. Remove instrument panel assembly. Refer to IP-14, "
Removal and Installation".
6. Remove steering column mounting bolt and nuts. Refer to ST-34, "
Removal and Installation".
7. Move steering column assembly to a position where it does not inhibit work.
8. Disconnect harness clips, harness connectors, ground bol ts and blackets from steering member, and then
move the vehicle harness to the position without hindrance for work.
9. Remove mounting nuts, and then remove instrument stay (RH and LH).
10. Remove A/C unit assembly mounting bolts.
11. Remove mounting bolts, and then remove steering member from the vehicle.
12. Disconnect drain hose from A/C unit assembly, and then remove A/C unit assembly from the vehicle.
13. Remove mounting bolts, and then disconnect heater & cooling unit and blower unitassembly.
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".
NOTE:
Refer to CO-9, "
Refilling" when filling radiator with engine coolant.
EVAPORATOR
EVAPORATOR : Removal and InstallationINFOID:0000000006276184
REMOVAL
1. Remove heater & cooling unit assembly. Refer to HA-41, "Exploded View".
2. Remove heater core. Refer to HA-44, "
HEATER CORE : Removal and Installation".
3. Remove mounting screws, and then remove evaporator pipe cover.
4. Remove air mix door motor (RH). Refer to HAC-153, "
AIR MIX DOOR MOTOR : Removal and Installa-
tion".
5. Remove mounting screws, and then remove A/C cover.
6. Remove foot duct LH. Refer to VTL-11, "
FLOOR DUCT 1 : Removal and Installation".
7. Remove mounting screws, and then remove A/C lower case.
8. Remove intake sensor. Refer to HAC-150, "
Removal and Installation".
9. Remove evaporator assembly from heater & cooling unit assembly.
10. Remove mounting bolts, and then remove evaporator from evaporator assembly.
CAUTION:
Cap or wrap the joint of the evaporator and evaporat or pipe assembly with suitable material such as
vinyl tape to avoid the entry of air.
Revision: 2010 May2011 QX56