cooling INFINITI QX56 2004 Factory Owner's Guide

ATC-146
HEATER & COOLING UNIT ASSEMBLY
Revision: August 20072004 QX56
4. Remove the exhaust system. Refer to EX-3, "Removal and Installation" .
5. Disconnect the front heater hoses from the front heater core.
6. Disconnect the high/low pressure pipes from the front expansion valve.
7. Move the two front seats to the rearmost position on the seat track.
8. Remove the instrument panel and console panel. Refer to IP-10, "
INSTRUMENT PANEL ASSEMBLY" .
9. Remove the steering column. Refer to PS-10, "
Removal and Installation" .
10. Disconnect the instrument panel wire harness at the RH and LH in-line connector brackets, and the fuse
block (J/B) electrical connectors. Refer to PG-40, "
Harness Layout" .
11. Disconnect the steering member from each side of the vehicle body.
12. Remove the front heater and cooling unit assembly with it attached to the steering member, from the vehi-
cle.
CAUTION:
Use care not to damage the seats and interior trim panels when removing the front heater and
cooling unit assembly with it attached to the steering member.
13. Remove the front heater and cooling unit assembly from the steering member.
Installation
Installation is in the reverse order of removal.
CAUTION:

Replace the O-ring of the low-pressure pipe and high-pressure pipe with a new one, and apply
compressor oil to it when installing it.

After charging the refrigerant, check for leaks.
NOTE:

Fill the engine cooling system with the specified coolant mixture. Refer to MA-13, "REFILLING ENGINE
COOLANT" .

Recharge the A/C system. Refer to ATC-162, "Evacuating System and Charging Refrigerant" .
REAR HEATER AND COOLING UNIT ASSEMBLY
Removal
1. Discharge the refrigerant from the A/C system. Refer to ATC-162, "Discharging Refrigerant" .
2. Drain the coolant from the engine cooling system. Refer to MA-12, "
DRAINING ENGINE COOLANT" .
3. Disconnect the rear heater core hoses from the rear heater core.
4. Disconnect the rear A/C pipes from the rear expansion valve.
5. Remove the rear RH interior trim panel. Refer to EI-34,
"Removal and Installation" .
6. Disconnect the following electrical connectors:

Rear blower motor

Rear blower motor resistor

Rear air mix door motor
7. Disconnect the ducts from the rear heater and cooling unit
assembly.
8. Remove the rear heater and cooling unit assembly.
Installation
Installation is in the reverse order of removal.
CAUTION:

Replace the O-ring of the low-pressure pipe and high-pressure pipe with a new one, and apply
compressor oil to it when installing it.

After charging the refrigerant, check for leaks.
NOTE:

Fill the engine cooling system with the specified coolant mixture. Refer to MA-13, "REFILLING ENGINE
COOLANT" .

Recharge the A/C system. Refer to ATC-162, "Evacuating System and Charging Refrigerant" .
LJIA0021E

HEATER CORE
ATC-147
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Revision: August 20072004 QX56
HEATER COREPFP:27140
ComponentsEJS002D6
Front Heater and Cooling Unit Assembly
LJIA0138E
1. Heater core cover 2. Heater core pipe bracket 3. Heater core
4. Upper bracket 5. Upper heater and cooling unit case 6. A/C evaporator
7. Lower heater and cooling unit case 8. Blower motor 9. Variable blower control

ATC-148
HEATER CORE
Revision: August 20072004 QX56
Rear Heater and Cooling Unit Assembly
Removal and InstallationEJS002D7
FRONT HEATER CORE
Removal
1. Remove the front heater and cooling unit assembly. Refer to ATC-145, "FRONT HEATER AND COOLING
UNIT ASSEMBLY" .
2. Remove the four screws and remove the upper bracket.
3. Remove the four screws and remove the heater core cover.
4. Remove the heater core pipe bracket.
LJIA0135E
1. Front cover 2. Evaporator and heater core case 3. Evaporator
4. Side cover 5. Heater core 6. Blower motor
7. Blower motor case 8. Blower motor resistor

HEATER CORE
ATC-149
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Revision: August 20072004 QX56
5. Remove the heater core.
NOTE:
If the in-cabin microfilters are contaminated from coolant leaking
from the heater core, replace the in-cabin microfilters with new
ones before installing the new heater core.
Installation
Installation is in the reverse order of removal.
REAR HEATER CORE
Removal
1. Partially drain the engine cooling system. Refer to MA-12, "DRAINING ENGINE COOLANT" .
2. Remove the rear RH interior trim panel. Refer to EI-34, "
Removal and Installation" .
3. Disconnect the rear heater hoses from the heater core.
4. Remove the rear heater core bracket.
5. Remove the heater core.
Installation
Installation is in the reverse order of removal.
LJIA0134E
LJIA0069E
LJIA0071E

ATC-150
DEFROSTER DOOR MOTOR
Revision: August 20072004 QX56
DEFROSTER DOOR MOTORPFP:27733
Removal and InstallationEJS002D8
Defroster Door Motor - Front Heater and Cooling Unit Assembly
REMOVAL
1. Remove the front heater and cooling unit assembly. Refer to ATC-145, "FRONT HEATER AND COOLING
UNIT ASSEMBLY" .
2. Remove the steering member from the front heater and cooling unit assembly.
3. Disconnect the defroster door motor electrical connector.
4. Remove the three screws and remove the defroster door motor.
INSTALLATION
Installation is in the reverse order of removal.
LJIA0139E
1. Front heater and cooling unit assembly 2. Intake door motor 3. Air mix door motor (driver)
4. Variable blower control 5. Air mix door motor (passenger) 6. Mode door motor
7. Defroster door motor

INTAKE DOOR MOTOR
ATC-151
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Revision: August 20072004 QX56
INTAKE DOOR MOTORPFP:27730
Removal and InstallationEJS002D9
Intake Door Motor - Front Heater and Cooling Unit Assembly
REMOVAL
1. Remove the front heater and cooling unit assembly. Refer to ATC-145, "FRONT HEATER AND COOLING
UNIT ASSEMBLY" .
2. Remove the steering member from the front heater and cooling unit assembly.
3. Disconnect the intake door motor electrical connector.
4. Remove the three screws and remove the intake door motor.
INSTALLATION
Installation is in the reverse order of removal.
LJIA0139E
1. Front heater and cooling unit assembly 2. Intake door motor 3. Air mix door motor (driver)
4. Variable blower control 5. Air mix door motor (passenger) 6. Mode door motor
7. Defroster door motor

ATC-152
MODE DOOR MOTOR
Revision: August 20072004 QX56
MODE DOOR MOTORPFP:27731
Removal and InstallationEJS002DA
Mode Door Motor - Front Heater and Cooling Unit Assembly
REMOVAL
1. Remove the front heater and cooling unit assembly. Refer to ATC-145, "FRONT HEATER AND COOLING
UNIT ASSEMBLY" .
2. Remove the steering member from the front heater and cooling unit assembly.
3. Disconnect the mode door motor electrical connector.
4. Remove the two screws and remove the mode door motor.
INSTALLATION
Installation is in the reverse order of removal.
LJIA0139E
1. Front heater and cooling unit assembly 2. Intake door motor 3. Air mix door motor (driver)
4. Variable blower control 5. Air mix door motor (passenger) 6. Mode door motor
7. Defroster door motor

AIR MIX DOOR MOTOR
ATC-153
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Revision: August 20072004 QX56
AIR MIX DOOR MOTOR PFP:27732
ComponentsEJS002DB
Air Mix Door Motors - Front Heater and Cooling Unit Assembly
Removal and InstallationEJS002DC
FRONT AIR MIX DOOR MOTOR (DRIVER)
Removal
1. Remove the front heater and cooling unit assembly. Refer to ATC-145, "FRONT HEATER AND COOLING
UNIT ASSEMBLY" .
2. Remove the steering member from the front heater and cooling unit assembly.
3. Disconnect the air mix door motor electrical connector.
4. Remove the three screws and remove the air mix door motor.
Installation
Installation is in the reverse order of removal.
LJIA0139E
1. Front heater and cooling unit assembly 2. Intake door motor 3. Air mix door motor (driver)
4. Variable blower control 5. Air mix door motor (passenger) 6. Mode door motor
7. Defroster door motor

ATC-154
AIR MIX DOOR MOTOR
Revision: August 20072004 QX56
FRONT AIR MIX DOOR MOTOR (PASSENGER)
Removal
1. Remove the front heater and cooling unit assembly. Refer to ATC-145, "FRONT HEATER AND COOLING
UNIT ASSEMBLY" .
2. Remove the steering member from the front heater and cooling unit assembly.
3. Disconnect the air mix door motor electrical connector.
4. Remove the three screws and remove the air mix door motor.
Installation
Installation is in the reverse order of removal.
REAR AIR MIX DOOR MOTOR
Removal
1. Remove the RH rear interior trim panel. Refer to EI-34, "Removal and Installation" .
2. Disconnect the rear air mix door motor electrical connector.
3. Remove the three screws and remove the rear air mix door
motor.
Installation
Installation is in the reverse order of removal.
LJIA0021E

VARIABLE BLOWER CONTROL
ATC-155
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Revision: August 20072004 QX56
VARIABLE BLOWER CONTROLPFP:27200
Removal and InstallationEJS002DD
Variable Blower Control - Front Heater and Cooling Unit Assembly
REMOVAL
1. Remove the front heater and cooling unit assembly. Refer to ATC-145, "FRONT HEATER AND COOLING
UNIT ASSEMBLY" .
2. Remove the steering member from the front heater and cooling unit assembly.
3. Disconnect the variable blower control electrical connector.
4. Remove the two screws and remove the variable blower control.
INSTALLATION
Installation is in the reverse order of removal.
LJIA0139E
1. Front heater and cooling unit assembly 2. Intake door motor 3. Air mix door motor (driver)
4. Variable blower control 5. Air mix door motor (passenger) 6. Mode door motor
7. Defroster door motor