2006 INFINITI QX56 Charging system

ATC-154
HEATER & COOLING UNIT ASSEMBLY
Revision: November 20092006 QX56
Rear Heater and Cooling Unit Assembly
Removal and InstallationEJS003YF
FRONT HEATER AND COOLING UNIT ASSEMBLY
Removal
1. Move the two front seats to the rearmost position on the seat track.
2. Disconnect the battery negative terminal and battery positive terminal.
3. Discharge the refrigerant from the A/C system. Refer to ATC-171, "
Discharging Refrigerant" .
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.

HEATER & COOLING UNIT ASSEMBLYATC-155
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Revision: November 2009 2006 QX56
4. Drain the coolant from the engine cooling system. Refer to MA-13, "DRAINING ENGINE COOLANT" .
5. Disconnect the front heater hoses from the front heater core.
6. Disconnect the high/low pressure pipes from the front expansion valve.
7. Remove the instrument panel and console panel. Refer to IP-10, "
INSTRUMENT PANEL ASSEMBLY" .
8. Remove the steering column. Refer to PS-10, "
STEERING COLUMN" .
9. 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-4, "
POWER SUPPLY ROUTING CIRCUIT" .
10. Disconnect the steering member from each side of the vehicle body.
11. 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.
12. 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-14, "REFILLING ENGINE
COOLANT" .

Recharge the A/C system. Refer to ATC-171, "Evacuating System and Charging Refrigerant" .
REAR HEATER AND COOLING UNIT ASSEMBLY
Removal
1. Discharge the refrigerant from the A/C system. Refer to ATC-171, "Discharging Refrigerant" .
2. Drain the coolant from the engine cooling system. Refer to MA-13, "
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 luggage side finisher lower RH. Refer to EI-35,
"BODY SIDE TRIM" .
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-14, "REFILLING ENGINE
COOLANT" .

Recharge the A/C system. Refer to ATC-171, "Evacuating System and Charging Refrigerant" .
LJIA0021E

REFRIGERANT LINESATC-171
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REFRIGERANT LINESPFP:92600
HFC-134a (R-134a) Service ProcedureEJS003YR
SETTING OF SERVICE TOOLS AND EQUIPMENT
Discharging Refrigerant
WARNING:
Avoid breathing A/C refrigerant and oil vapor or mist. Exposure may irritate eyes, nose and throat.
Remove HFC-134a (R-134a) refrigerant from the A/C system using certified service equipment meeting
requirements of SAE J2210 HFC-134a (R-134a) recycling equipment or SAE J2201 HFC-134a (R-134a)
recovery equipment. If an accidental system discharge occurs, ventilate the work area before resum-
ing service. Additional health and safety information may be obtained from the refrigerant and oil man-
ufacturers.
Evacuating System and Charging Refrigerant
1. Shut-off valve2. A/C service valve 3. Recovery/recycling equipment
WJIA0579E
1. Shut-off valve 2. A/C service valve3. Recovery/recycling equipment
4. Refrigerant container (HFC-134a) 5. Weight scale (J-39650) 6. Evacuating vacuum pump (J-39699)
7. Manifold gauge set (J-39183)
WJIA0580E

ATC-176
REFRIGERANT LINES
Revision: November 20092006 QX56
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:

Replace the O-rings of the low-pressure flexible hose and high-pressure flexible hose with new
ones, apply compressor oil to the O-rings when installing them.

After recharging the A/C system with refrigerant, check for leaks.
Removal and Installation for Compressor ClutchEJS003YU
Magnet Clutch Assembly
REMOVAL
1. Remove the compressor. Refer to ATC-175, "Removal and Installation for Compressor" .
2. Remove the center bolt while holding the clutch disc stationary using Tool as shown.
3. Remove the clutch disc.
4. Remove the snap ring using external snap ring pliers or suitable tool.
WJIA0372E
1. Magnet clutch assembly 2. Magnet coil 3. Pulley
4. Clutch disc 5. Snap ring 6. Thermal protector (built in)
7. Compressor
Tool number : J-44614
WHA228
RHA072C

ATC-180
REFRIGERANT LINES
Revision: November 20092006 QX56
CAUTION:

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

After charging refrigerant, check for leaks.
Removal and Installation for Low-pressure PipeEJS003YY
REMOVAL
1. Discharge the refrigerant. Refer to ATC-171, "HFC-134a (R-134a) Service Procedure" .
2. Remove the cowl top and the cowl top extension. Refer to EI-18, "
COWL TOP" .
3. Remove the low-pressure pipe. CAUTION:
Cap or wrap the joint of the pipes with suitable material such as vinyl tape to avoid the entry of air.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-173, "
Components" .
CAUTION:

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

After charging refrigerant, check for leaks.
Removal and Installation for Rear High- and Low-pressure A/C and Heater Core
Pipes
EJS005Y8
REMOVAL
1. Discharge the refrigerant. Refer to ATC-171, "HFC-134a (R-134a) Service Procedure" .
2. Drain the coolant from the engine cooling system. Refer to CO-10, "
Changing Engine Coolant" .
3. Disconnect the underfloor rear heater hoses (1 and 2) from the rear heater pipes underneath the vehicle.

⇐: Front
4. Remove the rear high- and low-pressure pipes bolt (A) to dis- connect the rear high- and low-pressure pipes from the under-
floor rear high- and low-pressure pipes underneath the vehicle.
CAUTION:
Cap or wrap the joint of the pipes with suitable material
such as vinyl tape to avoid the entry of air.
5. Remove the rear high- and low-pressure pipes nuts (B) under- neath the vehicle.
NOTE:
The remaining steps are performed inside the rear luggage area of the vehicle.
6. Remove the luggage side finisher lower RH. Refer to EI-40, "
LUGGAGE FLOOR TRIM" .
7. Disconnect the rear heater core hoses (1 and 2) from the rear heater core (3).

⇐: Front
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WJIA2311E

REFRIGERANT LINESATC-181
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Revision: November 2009 2006 QX56
8. Remove the rear high- and low-pressure pipes bracket bolt (A)
to release the bracket.

Rear blower motor (1)

⇐: Front
9. Remove the rear high- and low-pressure pipes bolt (A) to dis- connect the rear high- and low-pressure pipes from the rear
expansion valve (1).

⇐: Front
CAUTION:
Cap or wrap the joint of the pipes with suitable material
such as vinyl tape to avoid the entry of air.
10. Disconnect the following electrical connectors:

Rear air mix door motor (1)

Rear blower motor resistor (2)

Rear blower motor (3)

⇐ : Front
11. Disconnect the ducts from the rear heater and cooling unit assembly. Refer to ATC-166, "
Components" .
12. Remove the rear heater and cooling unit assembly. CAUTION:
Cap or wrap the joint of the pipes with suitable material such as vinyl tape to avoid the entry of air.
13. Remove the rear high- and low-pressure A/C pipes.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-173, "
Components" .
CAUTION:

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

After charging refrigerant, check for leaks.
Removal and Installation for Underfloor Rear High- and Low-pressure A/C and
Heater Core Pipes
EJS005Y9
REMOVAL
1. Drain the coolant from the engine cooling system. Refer to CO-10, "Changing Engine Coolant" .
2. Disconnect the battery negative terminal.
3. Disconnect the generator harness.
4. Discharge the refrigerant. Refer to ATC-171, "
HFC-134a (R-134a) Service Procedure" .
WJIA2312E
WJIA2313E
WJIA2314E

REFRIGERANT LINESATC-187
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Revision: November 2009 2006 QX56
CAUTION:
Cap or wrap the A/C refrigerant pipe ends with a suitable material such as vinyl tape to avoid the
entry of air and contaminants.
4. Remove the expansion valve.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:

Replace the O-rings on the A/C refrigerant pipes with new ones, then apply compressor oil to them
when installing them.

After charging refrigerant, check for leaks.
Checking for Refrigerant LeaksEJS003Z5
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 electronic 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 leak detector probe slower and closer to the suspected leak area will
improve the chances of finding a leak.
Checking System for Leaks Using the Fluorescent Dye Leak DetectorEJS003Z6
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). Illuminate 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 assembly 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 fluorescent 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 the 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 trigger 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 refrigerant leak detector (J-41995) to contact with any sub-
stance. This can also cause false readings and may damage the detector.
Dye InjectionEJS003Z7
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).
Expansion valve bolts : 4 N·m (0.41 kg-m, 35 in-lb)
A/C refrigerant pipe to expansion valve bolt : Refer to
ATC-173, "
Components"
.

DI-6
COMBINATION METERS
Revision: November 20092006 QX56
POWER SUPPLY AND GROUND CIRCUIT
Power is supplied at all times

through 10A fuse [No.19, located in the fuse block (J/B)]

to combination meter terminal 8.
With the ignition switch in the ON or START position, power is supplied

through 10A fuse [No.14, located in the fuse block (J/B)]

to combination meter terminal 24.
With the ignition switch in the ACC or ON position, power is supplied

through 10A fuse [No.4, located in the fuse block (J/B)]

to combination meter terminal 1.
Ground is supplied

to combination meter terminal 17

through body grounds M57, M61 and M79.
WATER TEMPERATURE GAUGE
The water temperature gauge indicates the engine coolant temperature.
ECM provides an engine coolant temperature signal to combination meter via CAN communication lines.
ENGINE OIL PRESSURE GAUGE
The engine oil pressure gauge indicates the engine oil pressure.
The engine oil pressure gauge is regulated by the unified meter control unit and input from the oil pressure
sensor.
A/T OIL TEMPERATURE GAUGE
The A/T oil temperature gauge indicates the A/T fluid temperature.
TCM (transmission control module) provides an A/T fluid temperature signal to combination meter via CAN
communication lines.
V O LTA G E G A U G E
The voltage gauge indicates the battery/charging system voltage.
The voltage gauge is regulated by the unified meter control unit.
TACHOMETER
The tachometer indicates engine speed in revolutions per minute (rpm).
ECM provides an engine speed signal to combination meter via CAN communication lines.
FUEL GAUGE
The fuel gauge indicates the approximate fuel level in the fuel tank.
The fuel gauge is regulated by the unified meter control unit and a variable resistor signal supplied

to combination meter terminal 15.

through fuel level sensor unit and fuel pump terminal 2

through fuel level sensor unit and fuel pump terminal 5

from combination meter terminal 16
SPEEDOMETER
ABS actuator and electric unit (control unit) provides a vehicle speed signal to the combination meter via CAN
communication lines.
CAN COMMUNICATION SYSTEM DESCRIPTION
Refer to LAN-26, "CAN COMMUNICATION" .