2006 INFINITI QX56 blower

TROUBLE DIAGNOSISATC-123
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Revision: November 2009 2006 QX56
*1ATC-176, "Removal and Installation
for Compressor Clutch"
*2ATC-93, "Front Blower Motor Circuit"*3 EM-13, "Checking Drive Belts"
WJIA1371E

ATC-124
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
PERFORMANCE CHART
Test Condition
Testing must be performed as follows:
Test Reading
Recirculating-to-discharge Air Temperature Table
Ambient Air Temperature-to-operating Pressure Table
Vehicle locationIndoors or in the shade (in a well-ventilated place)
Doors Closed
Door window Open
Hood Open
TEMP. Max. COLD
Mode switch (Ventilation) set
Recirculation (REC) switch (Recirculation) set
Blower speed Max. speed set
Engine speed Idle speed
Operate the air conditioning system for 10 minutes before taking measurements.
Inside air (Recirculating air) at blower assembly inlet Discharge air temperature at center ventilator
°C (°F)
Relative humidity
% Air temperature
°C (°F)
50 - 60 20 (68)
9.9 - 13.9 (50 - 57)
25 (77) 14.6 - 18.6 (58 - 65)
30 (86) 16.8 - 21.8 (62 - 71)
35 (95) 21.1 - 27.1 (70 - 81)
40 (104) 25.3 - 31.5 (78 - 89)
60 - 70 20 (68)
11.4 - 15.2 (53 - 59)
25 (77) 15.5 - 20.0 (60 - 68)
30 (86) 19.9 - 25.0 (68 - 77)
35 (95) 24.5 - 29.6 (76 - 85)
40 (104) 28.7 - 34.9 (84 - 95)
Ambient air High-pressure (Discharge side)
kPa (kg/cm
2 , psi) Low-pressure (Suction side)
kPa (kg/cm2 , psi)
Relative humidity
% Air temperature
°C (°F)
50 - 70 20 (68)
1020 - 1250
(10.4 - 12.7, 147.9 - 181.3) 160 - 190
(1.63 - 1.94, 23.2 - 27.6)
25 (77) 1236 - 1510
(12.6 - 15.4, 179.2 - 219) 206 - 245
(2.1 - 2.5, 29.9 - 35.6)
30 (86) 1569 - 1,922
(16.0 - 19.6, 227.6 - 278.8) 265 - 324
(2.7 - 3.3, 38.4 - 46.9)
35 (95) 1,697 - 2079
(17.3 - 21.2, 246.1 - 301.5) 304 - 363
(3.1 - 3.7, 44.1 - 52.6)
40 (104) 1971 - 2403
(20.1 - 24.5, 285.9 - 348.5) 373 - 451
(3.8 - 4.6, 54.0 - 65.4)

ATC-126
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
High-pressure Side is Too Low and Low-pressure Side is Too High
Both High- and Low-pressure Sides are Too Low
Gauge indicationRefrigerant cycleProbable causeCorrective action
High-pressure side is too low and
low-pressure side is too high. High- and low-pressure sides
become equal soon after com-
pressor operation stops.Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings.
Replace compressor.
No temperature difference
between high- and low-pres-
sure sides. Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings.
Replace compressor.
AC356A
Gauge indication
Refrigerant cycleProbable causeCorrective action
Both high- and low-pressure sides
are too low.

There is a big temperature
difference between liquid
tank outlet and inlet. Outlet
temperature is extremely
low.

Liquid tank inlet and expan-
sion valve are frosted. Liquid tank inside is slightly
clogged.

Replace liquid tank.

Check oil for contamination.

Temperature of expansion
valve inlet is extremely low
as compared with areas
near liquid tank.

Expansion valve inlet may
be frosted.

Temperature difference
occurs somewhere in high-
pressure side.High-pressure pipe located
between liquit tank and expan-
sion valve is clogged.

Check and repair malfunc-
tioning parts.

Check oil for contamination.
Expansion valve and liquid
tank are warm or only cool
when touched. Low refrigerant charge.
↓
Leaking fittings or compo-
nents.Check refrigerant system for
leaks. Refer to AT C - 1 8 7 ,
"Checking for Refrigerant
Leaks" .
There is a big temperature dif-
ference between expansion
valve inlet and outlet while the
valve itself is frosted. Expansion valve closes a little
compared with the specifica-
tion.
↓
1. Improper expansion valve
adjustment.
2. Malfunctioning expansion valve.
3. Outlet and inlet may be clogged.

Remove foreign particles by
using compressed air.

Check oil for contamination.
An area of the low-pressure
pipe is colder than areas near
the evaporator outlet. Low-pressure pipe is clogged
or crushed.

Check and repair malfunc-
tioning parts.

Check oil for contamination.
Air flow volume is too low. Evaporator is frozen.

Check intake sensor circuit.
Refer to ATC-142, "
Intake
Sensor Circuit" .

Repair evaporator fins.

Replace evaporator.

Refer to AT C - 9 3 , "Front
Blower Motor Circuit" .
AC353A

ATC-128
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Insufficient HeatingEJS003XX
SYMPTOM: Insufficient heating
INSPECTION FLOW
*1ATC-58, "Operational Check (Front)"
or AT C - 6 0 , "
Operational Check
(Rear)"
*2 AT C - 7 0 , "Air Mix Door Motor Circuit"*3ATC-56, "A/C System Self-diagno-
sis Function"
*4 ATC-57, "SELF-DIAGNOSIS CODE
CHART"
*5AT C - 9 3 , "Front Blower Motor Circuit"*6EC-192, "DTC P0117, P0118 ECT
SENSOR"
*7 EM-13, "Checking Drive Belts"*8ATC-132, "Water Valve Circuit"
WJIA1889E

BLOWER MOTORATC-149
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Revision: November 2009 2006 QX56
BLOWER MOTORPFP:27226
ComponentsEJS003YB
Front Blower Motor
Rear Blower Motor
Removal and InstallationEJS003YC
FRONT BLOWER MOTOR
Removal
1. Remove the glove box assembly. Refer to IP-14, "Lower Instrument Panel RH and Glove Box" .
2. Disconnect the front blower motor electrical connector.
3. Remove the three screws and remove the front blower motor.
Installation
Installation is in the reverse order of removal.
LJIA0136E
1. Front heater and cooling unit assembly 2. Front blower motor 3. Variable blower control
LJIA0055E
1. Rear blower motor2. Rear blower motor case 3. Rear blower motor resistor

ATC-150
BLOWER MOTOR
Revision: November 20092006 QX56
REAR BLOWER MOTOR
Removal
1. Remove the luggage side lower finisher RH. Refer to EI-40, "LUGGAGE FLOOR TRIM" .
2. Disconnect the rear blower motor electrical connector.
3. Remove the three screws and remove the rear blower motor.
Installation
Installation is in the reverse order of removal.
LJIA0056E

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