2008 INFINITI QX56 fl sensor

PRECAUTIONSHA-5
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General Refrigerant PrecautionINFOID:0000000001516632
WARNING:
• Do not release refrigerant into the air. Use appr oved recovery/recycling equipment to capture the
refrigerant every time an air co nditioning system is discharged.
• Always wear eye and hand protection (goggles and gloves) when working with any refrigerant or air
conditioning system.
• Do not store or heat refrigerant containers above 52 °C (125° F).
• Do not heat a refrigerant containe r with an open flame; if container warming is required, place the
bottom of the container in a warm pail of water.
• Do not intentionally drop, puncture, or incinerate refrigerant containers.
• Keep refrigerant away from open flames: poison ous gas will be produced if refrigerant burns.
• Refrigerant will displace oxygen, therefore be certain to work in well ventilated areas to prevent suf- focation.
• Do not pressure test or leak test HFC-134a (R-134a) service equipment and/or vehicle air condition-
ing systems with compressed air during repair. Some mixtures of air and HFC-134a (R-134a) have
been shown to be combustible at elevated pressures. These mixtures, if ignited, may cause injury or
property damage. Additional health and safety information may be obtained from refrigerant manu-
facturers.
Precaution for Leak Detection DyeINFOID:0000000001516633
• The A/C system contains a fluorescent leak detection dy e used for locating refrigerant leaks. An ultraviolet
(UV) lamp is required to illuminate the dye when inspecting for leaks.
• Always wear fluorescence enhancing UV safety goggles to protect your eyes and enhance the visibility of
the fluorescent dye.
• The fluorescent dye leak detector is not a replacement for an electronic refrigerant leak detector. The fluo-
rescent dye leak detector should be used in conjuncti on with an electronic refrigerant leak detector (J-
41995).
• For your safety and the customer's satisfaction, read and follow all manufacturer's operating instructions and precautions prior to performing work.
• A compressor shaft seal should not be repaired because of dye seepage. The compressor shaft seal should
only be repaired after confirming the leak with an electronic refrigerant leak detector (J-41995).
• Always remove any dye from the leak area after repairs are complete to avoid a misdiagnosis during a future service.
• Do not allow dye to come into contact with paint ed body panels or interior components. If dye is spilled,
clean immediately with the approved dye cleaner. Fluorescent dye left on a surface for an extended period of
time cannot be removed.
• Do not spray the fluorescent dye cleaning agent on hot surfaces (engine exhaust manifold, etc.).
• Do not use more than one refrigerant dye bot tle (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. Do not use HFC-
134a (R-134a) leak detection dye in CFC-12 (R-12) A/ C systems or CFC-12 (R-12) leak detection dye in
HFC-134a (R-134a) A/C systems or A/C system damage may result.
• The fluorescent properties of the dye will remain for over three (3) years unless a compressor failure occurs.
A/C Identification LabelINFOID:0000000001516634
Vehicles with factory installed fluorescent dye have this identification label on the underside of hood.
Precaution for Refrigerant ConnectionINFOID:0000000001516635
A new type refrigerant connection has been introduced to all refrigerant lines except the following locations.
• Expansion valve to cooling unit
• Evaporator pipes to evaporator (inside cooling unit)
• Refrigerant pressure sensor
FEATURES OF NEW TYPE REFRIGERANT CONNECTION
• The O-ring has been relocated. It has also been provided with a groove for proper installation. This reduces the possibility of the O-ring being caught in, or damaged by , the mating part. The sealing direction of the O-
ring is now set vertically in relation to the contacting surface of the mating part to improve sealing character-
istics.
Revision: March 2010 2008 QX56

PRECAUTIONSHA-7
< PRECAUTION >
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Front A/C
WJIA1578E
1. High-pressure service valve 2 . Grommet 3. High-pressure pipe
4. Refrigerant pressure sensor 5. Condenser 6. Compressor shaft seal
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
Revision: March 2010 2008 QX56

REFRIGERATION SYSTEMHA-17
< FUNCTION DIAGNOSIS >
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FUNCTION DIAGNOSIS
REFRIGERATION SYSTEM
Refrigerant CycleINFOID:0000000001516641
REFRIGERANT FLOW
The refrigerant flows in the standard pattern, that is, through the compressor, the condenser with liquid tank,
through the front and rear evaporators, and back to the compressor. The refrigerant evaporation through the
evaporator coils are controlled by front and rear externally equalized expansion valves, located inside the front
and rear evaporator cases.
Refrigerant System ProtectionINFOID:0000000001516642
REFRIGERANT PRESSURE SENSOR
The refrigerant system is protected against excessively hi gh or low pressures by the refrigerant pressure sen-
sor, located on the condenser. If the system pressure rises above or falls below the specifications, the refriger-
ant pressure sensor detects the pressure inside the refrigerant line and sends a voltage signal to the ECM.
The ECM de-energizes the A/C relay to disengage the magnetic compressor clutch when pressure on the high
pressure side detected by refrigerant pressu re sensor is over about 2,746 kPa (28 kg/cm
2, 398 psi), or below
about 120 kPa (1.22 kg/cm
2, 17.4 psi).
PRESSURE RELIEF VALVE
The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor.
When the pressure of refrigerant in the system incr eases to an abnormal level [more than 2,990 kPa (30.5 kg/
Revision: March 2010 2008 QX56

HA-24
< ON-VEHICLE MAINTENANCE >
FLUORESCENT LEAK DETECTOR
FLUORESCENT LEAK DETECTOR
Checking of Refrigerant LeaksINFOID:0000000001516646
PRELIMINARY CHECK
Perform a visual inspection of all refrigeration parts, fittings, hoses and components for signs of A/C oil leak-
age, damage, and corrosion. Any A/C oil leakage may indicate an area of refrigerant leakage. Allow extra
inspection time in these areas when using either an el ectronic refrigerant leak detector (J-41995) or fluores-
cent dye leak detector (J-42220).
If any dye is observed using a fluorescent dye leak detector (J-42220), confirm the leak using a electronic
refrigerant leak detector (J-41995). It is possible that the dye is from a prior leak that was repaired and not
properly cleaned.
When searching for leaks, do not stop when one leak is found but continue to check for additional leaks at all
system components and connections.
When searching for refrigerant leaks using an electronic refrigerant leak detector (J-41995), move the probe
along the suspected leak area at 25 - 50 mm (1 - 2 in) per second and no further than 6 mm (1/4 in) from the
component.
CAUTION:
Moving the electronic refrigerant l eak detector probe slower and closer to the suspected leak area will
improve the chances of finding a leak.
Checking System for L eaks Using the Fluorescent Dye Leak DetectorINFOID:0000000001516647
1. Check the A/C system for leaks using the fluorescent dye leak detector and safety goggles (J-42220) in a
low sunlight area (area without windows preferable). Il luminate all components, fittings and lines. The dye
will appear as a bright green/yellow area at the point of leakage. Fluorescent dye observed at the evapo-
rator drain opening indicates an evaporator core asse mbly leak (tubes, core or expansion valve).
2. If the suspected area is difficult to see, use an adjustable mirror or wipe the area with a clean shop rag or cloth, then inspect the shop rag or cloth with the fl uorescent dye leak detector (J-42220) for dye residue.
3. After the leak is repaired, remove any residual dye using refrigerant dye cleaner (J-43872) to prevent
future misdiagnosis.
4. Perform a system performance check and then verify t he leak repair using a electronic refrigerant leak
detector (J-41995).
NOTE:
• Other gases in the work area or substances on the A/C components, for example, anti-freeze, wind-
shield washer fluid, solvents and oils, may falsely tri gger the leak detector. Make sure the surfaces to be
checked are clean.
• Clean with a dry cloth or blow off with shop air.
• Do not allow the sensor tip of the electronic refri gerant leak detector (J-41995) to contact with any sub-
stance. This can also cause false readings and may damage the detector.
Dye InjectionINFOID:0000000001516648
NOTE:
This procedure is only necessary when recharging the system or when the compressor has seized and must
be replaced.
1. Check the A/C system static (at rest) pressure . Pressure must be at least 345 kPa (3.52 kg/cm
2 , 50 psi).
2. Pour one bottle 7.4 cc (1/4 ounce) of the HFC-134a (R -134a) fluorescent leak detection dye (J-41447) into
the HFC-134a (R-134a) dye injector (J-41459).
CAUTION:
If repairing the A/C system or replacing a co mponent, pour the HFC-134a (R-134a) fluorescent leak
detection dye (J-41447) directly into the open system connection and proceed with the service
procedures.
3. Connect the refrigerant dye injector (J-41459) to the low-pressure service valve.
4. Start the engine and switch the A/C system ON.
5. When the A/C system is operating (compressor running), inject one bottle 7.4 cc (1/4 ounce) of HFC-134a (R-134a) fluorescent leak detection dye (J-41447) through the low-pressure service valve using HFC-
134a (R-134a) dye injector (J-41459). Refer to the manufacturer's operating instructions.
Revision: March 2010 2008 QX56

ELECTRICAL LEAK DETECTORHA-27
< ON-VEHICLE MAINTENANCE >
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2. When checking for leaks, circle each fitting completely with the probe as shown.
3. Move the probe along each component at a speed of approxi- mately 25 - 50 mm (1 - 2 in)/second as shown.
CHECKING PROCEDURE
NOTE:
To prevent inaccurate or false readings, make sure t here is no refrigerant vapor, shop chemicals, or cigarette
smoke in the vicinity of the vehicle. Perform the leak test in a calm area (low air/wind movement) so that the
leaking refrigerant is not dispersed.
1. Turn the engine OFF.
2. Connect the manifold gauge set (J-39183-C) to the A/C service ports. Refer to HA-20, "
HFC-134a (R-
134a) Service Procedure".
3. Check if the A/C refrigerant pressu re is at least 345 kPa (3.52 kg/cm
2 , 50 psi) above a temperature of
16° C (61° F). If less than specification, recover/ev acuate and recharge the system with the specified
amount of refrigerant. Refer to HA-20, "
HFC-134a (R-134a) Service Procedure".
NOTE:
At temperatures below 16 °C (61° F), leaks may not be detected sinc e the system may not reach 345 kPa
(3.52 kg/cm
2 , 50 psi) pressure.
4. Perform the leak test from the high-pressure side (front A/C compressor discharge “a” to evaporator inlet “f” or rear piping connection “l”) to the low-pressure side (front A/C evaporator drain hose “g” to shaft seal
“k” and rear A/C evaporator drain hose “o” to piping connection “r”). Refer to HA-29, "
Component". Clean
the component to be checked and carefully move the electronic refrigerant leak detector probe completely
around the following connections and components.
• Check the compressor shaft seal
• Check the high and low-pressure pipe and hose fitt ings, relief valve, and compressor shaft seal
• Check the liquid tank
• Check the refrigerant pressure sensor
• Check all around the service valves. Check that the service valve caps are screwed tightly on the ser-
vice valves (to prevent leaks).
NOTE:
After removing manifold gauge set (J-39183-C) from the service valves, wipe any residue from the ser-
vice valves to prevent any false readings by the electronic refrigerant leak detector (J-41995).
• Evaporator
With engine OFF, turn blower fan on “High” for at least 15 seconds to dissipate any refrigerant trace in
the heater and cooling unit assembly. Wait a minimum of 10 minutes accumulation time (refer to the
manufacturer's recommended procedure for actual wait time) before inserting the electronic refrigerant
leak detector probe into the heater and cooling unit assembly drain hose.
NOTE:
SHA706E
SHA708EA
Revision: March 2010 2008 QX56

HA-30
< ON-VEHICLE REPAIR >
REFRIGERATION SYSTEM
Rear A/C System
NOTE:
Refer to HA-5, "
Precaution for Refrigerant Connection".
1. High-pressure service valve 2. Grommet 3. High-pressure pipe
4. Refrigerant pressure sensor 5. Condenser 6. Compressor shaft seal
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

HA-44
< ON-VEHICLE REPAIR >
CONDENSER
CONDENSER
Removal and Installation for CondenserINFOID:0000000001516658
REMOVAL
1. Discharge the refrigerant. Refer to HA-20, "HFC-134a (R-134a) Service Procedure".
2. Remove the radiator. Refer to CO-15, "
Removal and Installation".
CAUTION:
Be careful not to damage the core su rface of the condenser and the radiator.
3. Disconnect the high-pressure flexible hose and the high-pressure pipe from the condenser. CAUTION:
Cap or wrap the joint of the pipe with suitable ma terial such as vinyl tape to avoid the entry of air.
4. Disconnect the refrigerant pressure sensor connector. • Remove the refrigerant pressure sensor from the condenseras necessary.
5. Lift the condenser out of the mounting grommets to remove the condenser.
INSTALLATION
Installation is in the reverse order of removal.
Refer to HA-29, "
Component".
CAUTION:
• Replace the O-rings of the high-pressure pipe, refrigerant pressure sensor, and high-pressure flexi- ble hose with new ones, then apply compr essor oil to them when installing them.
• After charging refrigerant, check for leaks.
• Replace the grommets as necessary.
LJIA0145E
Revision: March 2010 2008 QX56

AMBIENT SENSORHA-45
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AMBIENT SENSOR
Removal and InstallationINFOID:0000000001516659
REMOVAL
1. Disconnect the ambient sensor electrical connector. NOTE:
The ambient sensor (1) is located behind the front bumper, in
front of the condenser.
2. Release the ambient sensor clip and then remove the ambient sensor (1).
INSTALLATION
Installation is in the reverse order of removal.
AWIIA0238ZZ
Revision: March 2010 2008 QX56