2006 INFINITI QX56 cooling

ATC-3
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DIAGNOSTIC PROCEDURE FOR IN-VEHICLE
SENSOR ..........................................................
. 138
COMPONENT INSPECTION ........................... . 140
Optical Sensor Circuit ......................................... . 140
COMPONENT DESCRIPTION ........................ . 140
OPTICAL INPUT PROCESS ........................... . 140
DIAGNOSTIC PROCEDURE FOR OPTICAL
SENSOR .......................................................... . 141
Intake Sensor Circuit ........................................... . 142
COMPONENT DESCRIPTION ........................ . 142
DIAGNOSTIC PROCEDURE FOR INTAKE SEN-
SOR ................................................................. . 142
COMPONENT INSPECTION ........................... . 143
CONTROL UNIT .................................................... . 144
Removal and Installation ..................................... . 144
FRONT AIR CONTROL ................................... . 144
REAR AIR CONTROL ...................................... . 144
AMBIENT SENSOR ............................................... . 145
Removal and Installation ..................................... . 145
REMOVAL ........................................................ . 145
INSTALLATION ................................................ . 145
IN-VEHICLE SENSOR ........................................... . 146
Removal and Installation ..................................... . 146
REMOVAL ........................................................ . 146
INSTALLATION ................................................ . 146
OPTICAL SENSOR ............................................... . 147
Removal and Installation ..................................... . 147
INTAKE SENSOR .................................................. . 148
Removal and Installation ..................................... . 148
REMOVAL ........................................................ . 148
INSTALLATION ................................................ . 148
BLOWER MOTOR ................................................. . 149
Components ........................................................ . 149
Removal and Installation ..................................... . 149
FRONT BLOWER MOTOR .............................. . 149
REAR BLOWER MOTOR ................................ . 150
IN-CABIN MICROFILTER ...................................... . 151
Removal and Installation ..................................... . 151
FUNCTION ....................................................... . 151
REPLACEMENT TIMING ................................. . 151
REPLACEMENT PROCEDURE ...................... . 151
HEATER & COOLING UNIT ASSEMBLY ............. . 153
Components ........................................................ . 153
Removal and Installation ..................................... . 154
FRONT HEATER AND COOLING UNIT ASSEM-
BLY ................................................................... . 154
REAR HEATER AND COOLING UNIT ASSEM-
BLY ................................................................... . 155
HEATER CORE ..................................................... . 156
Components ........................................................ . 156
Removal and Installation ..................................... . 157
FRONT HEATER CORE .................................. . 157
REAR HEATER CORE .................................... . 158
DEFROSTER DOOR MOTOR ............................... . 159
Removal and Installation ..................................... . 159
REMOVAL ........................................................ . 159
INSTALLATION ................................................ . 159INTAKE DOOR MOTOR ........................................
.160
Removal and Installation ..................................... .160
REMOVAL ........................................................ .160
INSTALLATION ................................................ .160
MODE DOOR MOTOR ........................................... .161
Removal and Installation ..................................... .161
REMOVAL ........................................................ .161
INSTALLATION ................................................ .161
AIR MIX DOOR MOTOR ........................................ .162
Components ........................................................ .162
Removal and Installation ..................................... .162
FRONT AIR MIX DOOR MOTOR (DRIVER) .... .162
FRONT AIR MIX DOOR MOTOR (PASSENGER) .163
REAR AIR MIX DOOR MOTOR ....................... .163
VARIABLE BLOWER CONTROL .......................... .164
Removal and Installation ..................................... .164
REMOVAL ........................................................ .164
INSTALLATION ................................................ .164
REAR BLOWER MOTOR RESISTOR ................... .165
Removal and Installation ..................................... .165
REMOVAL ........................................................ .165
INSTALLATION ................................................ .165
DUCTS AND GRILLES .......................................... .166
Components ........................................................ .166
Removal and Installation ..................................... .169
CENTER CONSOLE HEAT DUCT AND REAR
FINISHER ASSEMBLY GRILLE ....................... .169
DEFROSTER NOZZLE .................................... .169
RH AND LH SIDE DEMISTER DUCT .............. .169
RH AND LH VENTILATOR DUCT .................... .169
CENTER VENTILATOR DUCT ........................ .169
FLOOR DUCT .................................................. .169
REAR OVERHEAD DUCTS ............................. .170
REAR FLOOR DUCT ....................................... .170
GRILLES .......................................................... .170
REFRIGERANT LINES .......................................... .171
HFC-134a (R-134a) Service Procedure .............. .171
SETTING OF SERVICE TOOLS AND EQUIP-
MENT ............................................................... .171
Components ........................................................ .173
Removal and Installation for Compressor ........... .175
REMOVAL ........................................................ .175
INSTALLATION ................................................ .176
Removal and Installation for Compressor Clutch . 176 REMOVAL ........................................................ .176
INSPECTION ................................................... .177
INSTALLATION ................................................ .177
BREAK-IN OPERATION ................................... .179
Removal and Installation for Low-pressure Flexible
Hose .................................................................... .179
REMOVAL ........................................................ .179
INSTALLATION ................................................ .179
Removal and Installation for High-pressure Flexible
Hose .................................................................... .179
REMOVAL ........................................................ .179
INSTALLATION ................................................ .179
Removal and Installation for High-pressure Pipe . 179 REMOVAL ........................................................ .179
INSTALLATION ................................................ .179

PRECAUTIONSATC-7
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Revision: November 2009 2006 QX56
Precautions for Refrigerant ConnectionEJS003WU
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.
SHA815E

PRECAUTIONSATC-9
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Rear A/C
1. High-pressure service valve 2. Grommet3. 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
WJIA2315E
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 specifications 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.

REFRIGERATION SYSTEMATC-21
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REAR REFRIGERATION SYSTEM
1. Defroster nozzle2. LH side demister duct3. LH ventilator duct
4. RH side demister duct 5. RH ventilator duct6. Center ventilator duct
7. Front heater and cooling unit assembly 8. Floor duct 9. Clips
10. Heat duct
1. Rear floor duct 2. Rear heater and cooling unit assembly 3. Rear lower overhead duct
4. Rear upper overhead duct
LJIA0142E

ATC-22
OIL
Revision: November 20092006 QX56
OILPFP:KLG00
Maintenance of Oil Quantity in CompressorEJS003X4
The oil in the compressor circulates through the system with the refrigerant. Add oil to compressor when
replacing any component or after a large refrigerant leakage has occurred. It is important to maintain the spec-
ified amount.
If oil quantity is not maintained properly, the following malfunctions may result:

Lack of oil: May lead to a seized compressor

Excessive oil: Inadequate cooling (thermal exchange interference)
OIL
Name: NISSAN A/C System Oil Type S (DH-PS) or equivalent
Part number: KLH00-PAGS0
CHECKING AND ADJUSTING
CAUTION:
If excessive oil leakage is noted, do not perform the oil return operation.
Start the engine and set the following conditions:
Test Condition

Engine speed: Idling to 1,200 rpm

A/C switch: On

Blower fan 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 oil return operation for about ten minutes
Adjust the oil quantity according to the following table.
Oil Adjusting Procedure for Components Replacement Except Compressor
After replacing any of the following major components, add the correct amount of oil to the system.
Amount of oil to be added :

*1: If refrigerant leak is small, no addition of oil is needed.
Part replaced Oil to be added to system
Remarks
Amount of oil
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 leak 30 (1.0, 1.1)
Large leak
— Small leak *1

TROUBLE DIAGNOSISATC-39
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Revision: November 2009 2006 QX56
How to Perform Trouble Diagnosis for Quick and Accurate RepairEJS003XF
WORK FLOW
SYMPTOM TABLE
*1AT C - 5 8 , "Operational Check (Front)"
or ATC-60, "
Operational Check
(Rear)" .
SHA900E
Symptom Reference Page
A/C system does not come on. Go to Trouble Diagnosis Procedure for A/C System. AT C - 6 1
A/C system display is malfunctioning. Go to Navigation System. AV- 8 4
A/C system cannot be controlled.Go to Self-diagnosis Function. AT C - 5 6
Air outlet does not change.
Go to Trouble Diagnosis Procedure for Mode Door Motor. AT C - 6 4
Mode door motor is malfunctioning.
Discharge air temperature does not change.
Go to Trouble Diagnosis Procedure for Air Mix Door Motor. AT C - 7 0
Air mix door motor is malfunctioning.
Intake door does not change.
Go to Trouble Diagnosis Procedure for Intake Door Motor. AT C - 8 3
Intake door motor is malfunctioning.
Defroster door motor is malfunctioning. Go to Trouble Diagnosis Procedure for Defroster Door Motor. AT C - 8 7
Front blower motor operation is malfunction-
ing.Go to Trouble Diagnosis Procedure for Front Blower Motor.
AT C - 9 3
Rear blower motor operation is malfunction-
ing.Go to Trouble Diagnosis Procedure for Rear Blower Motor.
AT C - 1 0 1
Rear discharge air temperature and/or air
outlet does not change.Go to Trouble Diagnosis Procedure for Rear Air Control circuit.
AT C - 11 2
Magnet clutch does not engage.Go to Trouble Diagnosis Procedure for Magnet Clutch. AT C - 11 5
Insufficient coolingGo to Trouble Diagnosis Procedure for Insufficient Cooling. AT C - 1 2 1
Insufficient heatingGo to Trouble Diagnosis Procedure for Insufficient Heating. AT C - 1 2 8
NoiseGo to Trouble Diagnosis Procedure for Noise. AT C - 1 2 9
Self-diagnosis cannot be performed. Go to Trouble Diagnosis Procedure for Self-diagnosis. AT C - 1 3 0
Memory function does not operate.Go to Trouble Diagnosis Procedure for Memory Function. AT C - 1 3 1

ATC-58
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Operational Check (Front)EJS003XL
The purpose of the operational check is to confirm that the system operates properly.
CHECKING MEMORY FUNCTION
1. Set the temperature to 90°F or 32 °C.
2. Turn front blower control dial counterclockwise until system shuts OFF.
3. Turn ignition switch OFF.
4. Turn ignition switch ON.
5. Press the AUTO switch.
6. Confirm that the set temperature remains at previous temperature.
7. Turn front blower control counterclockwise until system shuts OFF.
If NG, go to trouble diagnosis procedure for ATC-131, "
Memory Function" .
If OK, continue with next check.
CHECKING BLOWER
1. Turn front blower control clockwise, blower should operate on low speed. The blower symbol should have one blade lit (on display).
2. Turn the front blower control dial again, and continue checking blower speed and blower symbol until all speeds are checked.
3. Leave blower on MAX speed.
If NG, go to trouble diagnosis procedure for AT C - 9 5 , "
DIAGNOSTIC PROCEDURE FOR BLOWER
MOTOR"AT C - 9 5 , "DIAGNOSTIC PROCEDURE FOR BLOWER MOTOR" .
If OK, continue with next check.
CHECKING DISCHARGE AIR
1. Press MODE switch four times and the DEF ( ) switch.
2. Each position indicator should change shape (on display).
3. Confirm that discharge air comes out according to the air distribution table. Refer to AT C - 3 0 , "
Discharge
Air Flow" .
Mode door position is checked in the next step.
If NG, go to trouble diagnosis procedure for AT C - 6 4 , "
Mode Door Motor Circuit" .
If OK, continue the 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 (, ONLY)
1. Press recirculation ( ) switch one time. Recirculation indicator should illuminate.
2. Press recirculation ( ) switch one more time. Recirculation indicator should go off.
3. Listen for intake door position change (blower sound should change slightly).
If NG, go to trouble diagnosis procedure for AT C - 8 3 , "
Intake Door Motor Circuit" .
If OK, continue the 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. REC ( ) is not allowed in DEF ( ) D/F ( ) or FOOT ( ).
CHECKING TEMPERATURE DECREASE
1. Rotate temperature control dial (driver side or passenger side) counterclockwise until 16 °C (60 °F) is dis-
played.
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 ATC-121,
"Insufficient Cooling" . If air mix door motor appears to be malfunctioning, go to AT C - 7 2 , "DIAGNOSTIC PRO-
CEDURE FOR AIR MIX DOOR MOTOR (DRIVER)" or AT C - 7 6 , "DIAGNOSTIC PROCEDURE FOR AIR MIX
DOOR MOTOR (PASSENGER)" .
If OK, continue the check. Conditions : Engine running and at normal operating temperature

ATC-60
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Operational Check (Rear)EJS003XM
The purpose of the operational check is to confirm that the system operates properly.
CHECKING BLOWER
1. Turn the rear blower control dial to switch position "1". Blower should operate on low speed.
2. Turn the rear blower control dial counterclockwise to switch position "2", "3", and "4" until all speeds are
checked.
3. Leave blower on MAX speed.
If NG, go to trouble diagnosis procedure for ATC-101, "
Rear Blower Motor Circuit" .
If OK, continue the check.
CHECKING TEMPERATURE DECREASE
1. Rotate temperature and mode dial fully counterclockwise.
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 ATC-121,
"Insufficient Cooling" . If air mix door motor appears to be malfunctioning, go to AT C - 7 9 , "DIAGNOSTIC PRO-
CEDURE FOR AIR MIX DOOR MOTOR (REAR)" .
If OK, continue the check.
CHECKING TEMPERATURE INCREASE
1. Rotate temperature and mode dial clockwise.
2. Check for hot 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 ATC-128,
"Insufficient Heating" . If air mix door motor appears to be malfunctioning, go to AT C - 7 9 , "DIAGNOSTIC PRO-
CEDURE FOR AIR MIX DOOR MOTOR (REAR)" .
If OK, continue the check. Conditions : Engine running and at normal operating temperature