INFINITI QX56 2011 Factory Service Manual

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)].
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HA-16
< BASIC INSPECTION >
DIAGNOSIS AND REPAIR WORKFLOW
BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
Work FlowINFOID:0000000006276148
OVERALL SEQUENCE
DETAILED FLOW
1.INTERVIEW FOR MALFUNCTION
Interview the symptom to the customer.
NNIIA0143GB
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DIAGNOSIS AND REPAIR WORKFLOWHA-17
< BASIC INSPECTION >
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>> GO TO 2.
2.SYMPTOM CHECK
Check the symptom from the customer's information. Check that any symptom occurs other than the inter-
viewed symptom.
Insufficient cooling/heating>>GO TO 3.
Refrigerant leakage>>GO TO 6.
Noise >> GO TO 7.
3.CONTROL SYSTEM DIAGNOSIS
Perform the system diagnosis for t he A/C control system. Refer to HAC-60, "
Work Flow".
Is A/C control system normal?
YES >> GO TO 4.
NO >> GO TO 8.
4.PERFORMANCE TEST
Perform the performance test. Check t he operation of each part. Refer to HA-25, "
Inspection".
>> GO TO 5.
5.TROUBLE DIAGNOSIS FOR UNUSUAL PRESSURE
Diagnose using a manifold gauge whenever system's high and/ or low side pressure(s) is/are unusual. Specify
the malfunctioning part. Refer to HA-27, "
Symptom Table".
Low refrigerant charge>>GO TO 6.
Except above>>GO TO 8.
6.CHECK REFRIGERANT FOR LEAKAGES
Check refrigerant for leakages. Specify the malfunctioning part. Refer to HA-18, "
Leak Test".
>> GO TO 8.
7.TROUBLE DIAGNOSIS FOR NOISE
Perform trouble diagnosis for noise. Specify the malfunctioning part. Refer to HA-29, "
Symptom Table".
>> GO TO 8.
8.MALFUNCTION PART REPAIR
Repair or replace the malfunctioning part.
>> GO TO 9.
9.REPAIR CHECK (OPERATION CHECK)
Check the operation of each part.
Does it operate normally?
YES >> INSPECTION END
NO >> GO TO 2.
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HA-18
< BASIC INSPECTION >
REFRIGERANT
REFRIGERANT
DescriptionINFOID:0000000006276149
CONNECTION OF SERVICE TOOLS AND EQUIPMENT
Leak TestINFOID:0000000006276150
CHECK REFRIGERANT LEAKAGE USING FLUORESCENT LEAK DETECTION DYE
1. Install a fender cover (1).
2. Wear UV safety goggles (2) provided with refrigerant dye leak detection kit.
3. Connect power cable (4) of UV lamp (6) to positive and negative terminals of the battery (3).
4. Press UV lamp switch (5) and check A/C system for refrigerant leakage. (Where refrigerant leakage
occurs, fluorescent leak detec tion dye appears in green color.)
WARNING:
1. Shut-off valve 2. A/C service valve 3. Recovery/recycling/recharging equipment
4. Refrigerant container (HFC-134a) 5. Weight scale (J-39650) 6. Vacuum pump (J-39649)
7. Manifold gauge set (J-39183)
A. Preferred (best) method B. Alternative method C. For charging
JSIIA0239ZZ
RJIA3815J
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REFRIGERANTHA-19
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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
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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
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REFRIGERANTHA-21
< BASIC INSPECTION >
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2. Operate recovery/recycling/recharging equipment, and evacuate air from A/C system for 25 minutes or
more.
CAUTION:
Evacuate air for 15 minutes or mo re if the parts are replaced.
3. Check the airtightness of A/C system for 25 minutes or more. If pressure rises more than the specified
level, charge A/C system with approximately 200 g (0.4 lb) refrigerant and check that there is no refriger-
ant leakage. Refer to HA-18, "
Leak Test".
CAUTION:
Check the airtightness for 15 minutes or more if the parts are replaced.
4. If parts other than compressor are replaced, fill comp ressor lubricant according to parts that are replaced.
5. Charge the specified amount of refrigerant to A/C system.
6. Check that A/C system operates normally.
7. Disconnect recovery/recycling/recharging equipment. (Co llect the refrigerant from the high-pressure hose
and low-pressure hose of recove ry/recycling/recharging equipment.)
8. Install A/C service valve cap.
9. Refrigerant charge is complete.
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
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LUBRICANTHA-23
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Lubricant Adjusting Procedur e for Compressor ReplacementINFOID:0000000006276157
1. Drain lubricant from removed compressor and measure lubricant amount.
1. Drain lubricant from high-pressure port (A) and low-pres-
sure port (B) while rotating magnet clutch.
2. Measure total amount of lubricant that is drained from removed compressor.
2. Drain lubricant from a new compressor that is calculated accord- ing to the following conditions.
CAUTION:
If lubricant amount that is drained from removed compressor is less than 60 m (2.1 Imp fl oz.),
perform calculation by setting “D” as 40 m (1.4 Imp fl oz.).
Conditions Lubricant amount to be added to A/C system
m (Imp fl oz.)
Replace evaporator A/C unit 75 (2.6)
Rear A/C unit 75 (2.6)
Replace condenser 75 (2.6)
Replace liquid tank 5 (0.2)
Refrigerant leakage is detected Large amount leakage 30 (1.1)
Small amount leakage —
Lubricant amount that is recycled together with refrigerant during recycle operation α
JMIIA0675ZZ
Amount to be drained (A) [m (Imp fl oz.)] = F − (D
+ S + R + α)
F : Lubricant amount that a new compressor contains [210 (7.1)]
D : Lubricant amount that is drained from re- moved compressor
S : Lubricant amount that remains inside of re-
moved compressor [20 (0.7)]
R : Lubricant amount to be added according to components that are removed except com-
pressor
α : Lubricant amount that is recycled together
with refrigerant during recycle operation
Conditions Lubricant amount to be added to A/C system
m (Imp fl oz.)
Replace evaporator Front 75 (2.6)
Rear 75 (2.6)
Replace condenser 75 (2.6)
Replace liquid tank 5 ( 0.2)
JPIIA1455GB
Revision: 2010 May2011 QX56

HA-24
< BASIC INSPECTION >
LUBRICANT
Example: Lubricant amount to be drained from a new compressor when replacing compressor and liquid
tank [m (Imp fl oz.)] [D = 60 (2.1), α = 5 (0.2)]
210 (7.2) − [60 (1.6) + 20 (0.7) + 5 (0.2) + 5 (0.2)] = 120 (4.2)
3. Install compressor and check the operation.
Revision: 2010 May2011 QX56