2004 INFINITI QX56 cooling

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Revision: August 20072004 QX56 SENSOR ........................................................... 129
COMPONENT INSPECTION ............................ 131
Optical Sensor Circuit .......................................... 131
COMPONENT DESCRIPTION ......................... 131
OPTICAL INPUT PROCESS ............................ 131
DIAGNOSTIC PROCEDURE FOR OPTICAL
SENSOR ........................................................... 132
Intake Sensor Circuit ............................................ 133
COMPONENT DESCRIPTION ......................... 133
DIAGNOSTIC PROCEDURE FOR INTAKE SEN-
SOR .................................................................. 133
COMPONENT INSPECTION ............................ 134
CONTROL UNIT ..................................................... 135
Removal and Installation ...................................... 135
FRONT AIR CONTROL .................................... 135
REAR AIR CONTROL ....................................... 135
AMBIENT SENSOR ................................................ 136
Removal and Installation ...................................... 136
REMOVAL ......................................................... 136
INSTALLATION ................................................. 136
IN-VEHICLE SENSOR ............................................ 137
Removal and Installation ...................................... 137
REMOVAL ......................................................... 137
INSTALLATION ................................................. 137
OPTICAL SENSOR ................................................ 138
Removal and Installation ...................................... 138
INTAKE SENSOR ................................................... 139
Removal and Installation ...................................... 139
REMOVAL ......................................................... 139
INSTALLATION ................................................. 139
BLOWER MOTOR .................................................. 140
Components ......................................................... 140
Removal and Installation ...................................... 140
FRONT BLOWER MOTOR ............................... 140
REAR BLOWER MOTOR ................................. 141
IN-CABIN MICROFILTER ....................................... 142
Removal and Installation ...................................... 142
FUNCTION ........................................................ 142
REPLACEMENT TIMING .................................. 142
REPLACEMENT PROCEDURE ....................... 142
HEATER & COOLING UNIT ASSEMBLY .............. 144
Components ......................................................... 144
Removal and Installation ...................................... 145
FRONT HEATER AND COOLING UNIT ASSEM-
BLY .................................................................... 145
REAR HEATER AND COOLING UNIT ASSEM-
BLY .................................................................... 146
HEATER CORE ...................................................... 147
Components ......................................................... 147
Removal and Installation ...................................... 148
FRONT HEATER CORE ................................... 148
REAR HEATER CORE ..................................... 149
DEFROSTER DOOR MOTOR ................................ 150
Removal and Installation ...................................... 150
REMOVAL ......................................................... 150
INSTALLATION ................................................. 150INTAKE DOOR MOTOR .........................................151
Removal and Installation ......................................151
REMOVAL .........................................................151
INSTALLATION .................................................151
MODE DOOR MOTOR ............................................152
Removal and Installation ......................................152
REMOVAL .........................................................152
INSTALLATION .................................................152
AIR MIX DOOR MOTOR .........................................153
Components .........................................................153
Removal and Installation ......................................153
FRONT AIR MIX DOOR MOTOR (DRIVER) .....153
FRONT AIR MIX DOOR MOTOR (PASSENGER) .154
REAR AIR MIX DOOR MOTOR ........................154
VARIABLE BLOWER CONTROL ...........................155
Removal and Installation ......................................155
REMOVAL .........................................................155
INSTALLATION .................................................155
REAR BLOWER MOTOR RESISTOR ....................156
Removal and Installation ......................................156
REMOVAL .........................................................156
INSTALLATION .................................................156
DUCTS AND GRILLES ...........................................157
Components .........................................................157
Removal and Installation ......................................160
CENTER CONSOLE HEAT DUCT AND REAR
FINISHER ASSEMBLY GRILLE ........................160
DEFROSTER NOZZLE .....................................160
RH AND LH SIDE DEMISTER DUCT ...............160
RH AND LH VENTILATOR DUCT .....................160
CENTER VENTILATOR DUCT .........................160
FLOOR DUCT ...................................................160
REAR OVERHEAD DUCTS ..............................160
REAR FLOOR DUCT ........................................161
GRILLES ...........................................................161
REFRIGERANT LINES ...........................................162
HFC-134a (R-134a) Service Procedure ...............162
SETTING OF SERVICE TOOLS AND EQUIP-
MENT ................................................................162
Components .........................................................164
Removal and Installation for Compressor ............166
REMOVAL .........................................................166
INSTALLATION .................................................167
Removal and Installation for Compressor Clutch . 167
REMOVAL .........................................................167
INSPECTION ....................................................168
INSTALLATION .................................................168
BREAK-IN OPERATION ....................................170
Removal and Installation for Low-pressure Flexible
Hose .....................................................................170
REMOVAL .........................................................170
INSTALLATION .................................................170
Removal and Installation for High-pressure Flexible
Hose .....................................................................170
REMOVAL .........................................................170
INSTALLATION .................................................170
Removal and Installation for High-pressure Pipe . 170
REMOVAL .........................................................170
INSTALLATION .................................................171

PRECAUTIONS
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Revision: August 20072004 QX56
A/C Identification LabelEJS002BK
Vehicles with factory installed fluorescent dye have this identification
label on the underside of hood.
Precautions for Refrigerant ConnectionEJS002BL
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
characteristics.

The reaction force of the O-ring will not occur in the direction that causes the joint to pull out, thereby facil-
itating piping connections.
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PRECAUTIONS
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Revision: August 20072004 QX56
Rear A/C
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
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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 motor 6. Underfloor rear A/C pipes
7. Underfloor rear heater core pipes A. Bolt torque specifications B. Leak checking order (l - r)
C. Tightening torque D. Wrench size E. O-ring size
⇐Front
NOTE: The O-ring size 8 is the high-side and the O-ring size 16 is the low-side.

REFRIGERATION SYSTEM
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REAR REFRIGERATION SYSTEM
1. Defroster nozzle 2. LH side demister duct 3. LH ventilator duct
4. RH side demister duct 5. RH ventilator duct 6. Center ventilator duct
7. Front heater and cooling unit assembly 8. Floor duct 9. Clips
1. Rear floor duct 2. Rear heater and cooling unit assembly 3. Rear lower overhead duct
4. Rear upper overhead duct
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ATC-22
LUBRICANT
Revision: August 20072004 QX56
LUBRICANTPFP:KLG00
Maintenance of Lubricant Quantity in CompressorEJS002BV
The lubricant in the compressor circulates through the system with the refrigerant. Add lubricant to compres-
sor when replacing any component or after a large refrigerant leakage has occurred. It is important to maintain
the specified amount.
If lubricant quantity is not maintained properly, the following malfunctions may result:

Lack of lubricant: May lead to a seized compressor

Excessive lubricant: Inadequate cooling (thermal exchange interference)
LUBRICANT
Name: NISSAN A/C System Lubricant Type S (DH-PS)
Part number: KLH00-PAGS0
CHECKING AND ADJUSTING
CAUTION:
If excessive lubricant leakage is noted, do not perform the lubricant return operation.
Start the engine and set the following conditions:
test condition

Engine speed: Idling to 1,200 rpm

A/C switch: On

Blower speed: Max. position

Temp. control: Optional [Set so that intake air temperature is 25 to 30° C (77 to 86°F).]

Intake position: Recirculation ( )

Perform lubricant return operation for about ten minutes
Adjust the lubricant quantity according to the following table.
Lubricant Adjusting Procedure for Components Replacement Except Compressor
After replacing any of the following major components, add the correct amount of lubricant to the system.
Amount of Lubricant to be Added
*1: If refrigerant leak is small, no addition of lubricant is needed.
Lubricant Adjustment Procedure for Compressor Replacement
1. Before connecting recovery/recycling equipment to vehicle, check recovery/recycling equipment gauges.
No refrigerant pressure should be displayed. If NG, recover refrigerant from equipment lines.
2. Connect recovery/recycling equipment to vehicle. Confirm refrigerant purity in supply tank using recovery/
recycling equipment and refrigerant identifier. If NG, refer to AT C - 5 , "
Contaminated Refrigerant" .
3. Confirm refrigerant purity in vehicle A/C system using recovery/recycling equipment and refrigerant identi-
fier. If NG, refer to AT C - 5 , "
Contaminated Refrigerant" .
4. Discharge refrigerant into the refrigerant recovery/recycling equipment. Measure lubricant discharged into
the recovery/recycling equipment.
5. Drain the lubricant from the “old” (removed) compressor into a graduated container and recover the
amount of lubricant drained.
6. Drain the lubricant from the “new” compressor into a separate, clean container.
Part replacedLubricant to be added to system
Remarks
Amount of lubricant
m (US fl oz, Imp fl oz)
Front evaporator 75 (2.5, 2.6) —
Rear evaporator 75 (2.5, 2.6) —
Condenser 75 (2.5, 2.6) —
Liquid tank 5 (0.2, 0.2) Add if compressor is not replaced.
In case of refrigerant leak30 (1.0, 1.1) Large leak
— Small leak *1

TROUBLE DIAGNOSIS
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How to Perform Trouble Diagnosis for Quick and Accurate RepairEJS002C5
WORK FLOW
SYMPTOM TABLE
*1ATC-56, "Operational Check (Front)"
or AT C - 5 9 , "
Operational Check
(Rear)" .
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Symptom Reference Page
A/C system does not come on. Go to Trouble Diagnosis Procedure for A/C System.AT C - 6 0 , "
Power
Supply and
Ground Circuit for
Front Air Control"
A/C system display is malfunctioning. Go to "Navigation System".AV-61, "NAVIGA-
TION SYSTEM"
A/C system cannot be controlled. Go to Self-diagnosis Function.AT C - 5 3 , "
A/C Sys-
tem Self-diagno-
sis Function"
Air outlet does not change.
Go to Trouble Diagnosis Procedure for Mode Door Motor.AT C - 6 3 , "Mode
Door Motor Cir-
cuit"Mode door motor is malfunctioning.
Discharge air temperature does not change.
Go to Trouble Diagnosis Procedure for Air Mix Door Motor.ATC-67, "
Air Mix
Door Motor Cir-
cuit"Air mix door motor is malfunctioning.
Intake door does not change.
Go to Trouble Diagnosis Procedure for Intake Door Motor.ATC-76, "
Intake
Door Motor Cir-
cuit"Intake door motor is malfunctioning.
Defroster door motor is malfunctioning. Go to Trouble Diagnosis Procedure for Defroster Door Motor.AT C - 7 9 ,
"Defroster Door
Motor Circuit"
Front blower motor operation is malfunction-
ing.Go to Trouble Diagnosis Procedure for Front Blower Motor.AT C - 8 3 , "Front
Blower Motor Cir-
cuit"
Rear blower motor operation is malfunction-
ing.Go to Trouble Diagnosis Procedure for Rear Blower Motor.AT C - 9 0 , "Rear
Blower Motor Cir-
cuit"
Rear discharge air temperature and/or air
outlet does not change.Go to Trouble Diagnosis Procedure for Rear Air Control circuit.ATC-101, "Rear
Air Control Circuit"
Magnet clutch does not engage. Go to Trouble Diagnosis Procedure for Magnet Clutch.ATC-104, "Mag-
net Clutch Circuit"
Insufficient cooling Go to Trouble Diagnosis Procedure for Insufficient Cooling.AT C - 11 0 , "Insuffi-
cient Cooling"
Insufficient heating Go to Trouble Diagnosis Procedure for Insufficient Heating.AT C - 11 7 , "Insuffi-
cient Heating"
Noise Go to Trouble Diagnosis Procedure for Noise.ATC-118, "Noise"

TROUBLE DIAGNOSIS
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Revision: August 20072004 QX56
CHECKING DISCHARGE AIR
1. Press MODE switch four times and then rotate the DEF dial
counterclockwise.
2. Each position indicator should change shape (on display).
3. Confirm that discharge air comes out according to the air distri-
bution table. Refer to AT C - 2 9 , "
Discharge Air Flow" .
Mode door position is checked in the next step.
If NG, go to trouble diagnosis procedure for ATC-63, "
Mode Door
Motor Circuit" .
If OK, continue with next check.
NOTE:
Confirm that the compressor clutch is engaged (sound or visual
inspection) and intake door position is at fresh when the DEF or D/F
is selected.
CHECKING RECIRCULATION
1. Press recirculation ( ) switch one time. Recirculation indica-
tor should illuminate.
2. Press recirculation ( ) switch one more time. Fresh ( )
indicator should illuminate.
3. Listen for intake door position change (blower sound should
change slightly).
If NG, go to trouble diagnosis procedure for AT C - 7 6 , "
Intake Door
Motor Circuit" .
If OK, continue with next check.
NOTE:
Confirm that the compressor clutch is engaged (sound or visual
inspection) and intake door position is at fresh when the DEF or D/F is selected.
CHECKING TEMPERATURE DECREASE
1. Rotate temperature dial counterclockwise (driver or passenger)
until 18°C (60°F) is displayed.
2. Check for cold air at appropriate discharge air outlets.
If NG, listen for sound of air mix door motor operation. If OK, go to
trouble diagnosis procedure for AT C - 11 0 , "
Insufficient Cooling" . If
air mix door motor appears to be malfunctioning, go to AT C - 6 9 ,
"DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR
(DRIVER)" or AT C - 7 1 , "DIAGNOSTIC PROCEDURE FOR AIR MIX
DOOR MOTOR (PASSENGER)" .
If OK, continue with next check.
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TROUBLE DIAGNOSIS
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Revision: August 20072004 QX56
Operational Check (Rear)EJS002CC
The purpose of the operational check is to confirm that the system operates properly.
CHECKING BLOWER
1. Turn the rear fan switch (front) clockwise to "1". The rear blower
should operate on low speed.
2. Turn the rear fan switch (front) clockwise again to switch position
"2", "3", and "4" until all speeds are checked.
3. Leave blower on maximum speed.
If NG, go to trouble diagnosis procedure for AT C - 9 0 , "
Rear Blower
Motor Circuit" .
If OK, continue with next check.
CHECKING TEMPERATURE DECREASE
1. Rotate rear temperature/mode dial (front) fully counterclockwise.
2. Check for cold air at appropriate discharge air outlets (headliner
outlets).
If NG, listen for sound of air mix door motor operation. If OK, go to
trouble diagnosis procedure for AT C - 11 0 , "
Insufficient Cooling" . If
air mix door motor appears to be malfunctioning, go to AT C - 7 3 ,
"DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR
(REAR)" .
If OK, continue with next check.
CHECKING TEMPERATURE INCREASE
1. Rotate rear temperature/mode dial (front) clockwise.
2. Check for hot air at appropriate discharge air outlets (floor out-
lets).
If NG, listen for sound of air mix door motor operation. If OK, go to
trouble diagnosis procedure for AT C - 11 7 , "
Insufficient Heating" . If
air mix door motor appears to be malfunctioning, go to AT C - 7 3 ,
"DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR
(REAR)" .
If OK, continue with next check.Conditions : Engine running and at normal operating temperature
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