check oil INFINITI QX56 2006 Factory Workshop Manual
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ATC-110
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
COMPONENT INSPECTION
Rear Blower Motor Relay
Check circuit continuity between terminals by supplying 12 volts and
ground to coil side terminals of relays.
Rear Blower Switch (Rear)
Check continuity between terminals at each switch position.
Rear Blower Switch (Front)
Check continuity between terminals at each switch position.
WJIA0973E
LJIA0113E
LJIA0114E 
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TROUBLE DIAGNOSISATC-125
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TROUBLE DIAGNOSES FOR UNUSUAL PRESSURE
Whenever system′s high and/or low side pressure is unusual, diagnose using a manifold gauge. The marker
above the gauge scale in the following tables indicates the standard (usual) pressure range. Since the stan-
dard (usual) pressure, however, differs from vehicle to vehicle, refer to above table (Ambient air temperature-
to-operating pressure table).
Both High- and Low-pressure Sides are Too High
High-pressure Side is Too High and Low-pressure Side is Too Low
Gauge indication Refrigerant cycleProbable causeCorrective action
Both high- and low-pressure sides 
are too high. Pressure is reduced soon 
after water is splashed on 
condenser.
Excessive refrigerant charge 
in refrigeration cycle
Reduce refrigerant until speci-
fied pressure is obtained.
Air suction by cooling fan is 
insufficient. Insufficient condenser cooling 
performance
↓
1. Condenser fins are clogged.
2. Improper fan rotation of 
cooling fan
Clean condenser.
Check and repair cooling fan 
if necessary.
Low-pressure pipe is not 
cold.
When compressor is 
stopped high-pressure 
value quickly drops by 
approximately 196 kPa (2 
kg/cm
2 , 28 psi). It then 
decreases gradually there-
after. Poor heat exchange in con-
denser
(After compressor operation 
stops, high-pressure 
decreases too slowly.)
↓
Air in refrigeration cycle
Evacuate and recharge sys-
tem.
Engine tends to overheat. Engine cooling systems mal-
function. Check and repair engine cool-
ing system.
An area of the low-pres-
sure pipe is colder than 
areas near the evaporator 
outlet.
Plates are sometimes cov-
ered with frost.
Excessive liquid refrigerant 
on low-pressure side
Excessive refrigerant dis-
charge flow
Expansion valve is open a 
little compared with the 
specification.
  ↓
Improper expansion valve 
adjustment Replace expansion valve.
AC359A
Gauge indication
Refrigerant cycleProbable causeCorrective action
High-pressure side is too high and 
low-pressure side is too low.
Upper side of condenser and 
high-pressure side are hot, 
however, liquid tank is not so 
hot.High-pressure tube or parts 
located between compressor 
and condenser are clogged or 
crushed.
Check and repair or replace 
malfunctioning parts.
Check oil for contamination.
AC360A 
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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 
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TROUBLE DIAGNOSISATC-127
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Low-pressure Side Sometimes Becomes Negative
Low-pressure Side Becomes Negative
Gauge indicationRefrigerant cycleProbable causeCorrective action
Low-pressure side sometimes 
becomes negative.
Air conditioning system 
does not function and does 
not cyclically cool the com-
partment air.
The system constantly func-
tions for a certain period of 
time after compressor is 
stopped and restarted. Refrigerant does not dis-
charge cyclically.
↓
Moisture is frozen at expan-
sion valve outlet and inlet.
↓
Water is mixed with refriger-
ant.
Drain water from refrigerant 
or replace refrigerant.
Replace liquid tank.
AC354A
Gauge indication
Refrigerant cycleProbable causeCorrective action
Low-pressure side becomes nega-
tive. Liquid tank or front/rear side of 
expansion valve′s pipe is 
frosted or dewed. High-pressure side is closed 
and refrigerant does not flow.
↓
Expansion valve or liquid tank 
is frosted.Leave the system at rest until 
no frost is present. Start it 
again to check whether or not 
the malfunction is caused by 
water or foreign particles.
If water is the cause, initially 
cooling is okay. Then the 
water freezes causing a 
blockage. Drain water from 
refrigerant or replace refrig-
erant.
If due to foreign particles, 
remove expansion valve 
and remove the particles 
with dry and compressed air 
(not shop air).
If either of the above meth-
ods cannot correct the mal-
function, replace expansion 
valve.
Replace liquid tank.
Check oil for contamination.
AC362A 
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TROUBLE DIAGNOSISATC-129
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NoiseEJS003XY
SYMPTOM: Noise
INSPECTION FLOW
*1ATC-175, "REMOVAL".* 2ATC-176, "INSTALLATION".*3 AT C - 2 2 ,  "Maintenance of Oil Quan-
tity in Compressor".
*4 AT C - 5 8 ,  "
Operational Check (Front)" 
or  ATC-60, "
Operational Check 
(Rear)" . *5
EM-13, "
Checking Drive Belts".
WJIA2293E 
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HEATER & COOLING UNIT ASSEMBLYATC-155
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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 
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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 
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REFRIGERANT LINESATC-177
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5. Remove the pulley using Tool with a small adapter. Position the
small adapter on the end of the drive shaft and the center of the
puller on the small adapter.
CAUTION:
To prevent deformation of the pulley groove, the puller
claws should be hooked under the pulley groove and not
into the pulley groove.
6. Remove the magnet coil harness clip using a screwdriver, remove the three magnet coil fixing screws and remove the
magnet coil.
INSPECTION
Clutch Disc
If the contact surface shows signs of damage due to excessive heat,
replace clutch disc and pulley.
Pulley
Check the appearance of the pulley assembly. If contact surface of pulley shows signs of excessive grooving,
replace clutch disc and pulley. The contact surfaces of the pulley assembly should be cleaned with a suitable
solvent before reinstallation.
Coil
Check magnet coil for loose connections or any cracked insulation.
INSTALLATION
1. Install the magnet coil.
CAUTION:
Be sure to align the magnet coil pin with the hole in the
compressor front head.Tool number : KV99233130 (J-29884)
WJIA1017E
WHA212
WHA183
WHA213 
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ATC-178
REFRIGERANT LINES
Revision: November 20092006 QX56
2. Install the magnet coil harness clip using a screwdriver.
3. Install the pulley assembly using Tool and a wrench, then install
the snap ring using snap ring pliers.
4. Install the clutch disc on the compressor shaft, together with the original shim(s). Press the clutch disc down by hand.
5. Install the clutch pulley bolt using Tool, to prevent the clutch disc from turning and tighten the bolt to specification.
CAUTION:
After tightening the clutch pulley bolt, check that the clutch
pulley rotates smoothly.
6. Check the pulley clearance all the way around the clutch disc as shown.
7. If the specified clearance is not obtained, replace the adjusting spacer to readjust.
8. Connect the compressor electrical connector.
9. Install the drive belt. Refer to  EM-13, "
DRIVE BELTS" .
10. Install the engine under cover and the splash shield. Tool number : — (J-38873-A)
WJIA1016E
WHA184
Tool number : J-44614
WHA229
Clutch disc-to-pulley clearance : 0.3 - 0.6 mm 
(0.012 - 0.024 in)
WHA194 
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REFRIGERANT LINESATC-179
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BREAK-IN OPERATION
When replacing compressor clutch assembly, always conduct the break-in operation. This is done by engag-
ing and disengaging the clutch about 30 times. Break-in operation raises the level of transmitted torque.
Removal and Installation for Low-pressure Flexible HoseEJS003YV
REMOVAL
1. Remove the engine room cover using power tools.
2. Remove the engine air cleaner and air ducts. Refer to EM-15, "
AIR CLEANER AND AIR DUCT"
3. Remove the cowl top extension. Refer to EI-18, "COWL TOP" . 
4. Discharge the refrigerant. Refer to ATC-171, "
HFC-134a (R-134a) Service Procedure" .
CAUTION:
Cap or wrap the joint of the pipe with suitable material such as vinyl tape to avoid the entry of air. 
5. Remove the low-pressure flexible hose.
INSTALLATION
Installation is in the reverse order of removal.
Refer to  ATC-173, "
Components" .
CAUTION:
Replace the O-ring of the low-pressure flexible hose with a new one, then apply compressor oil to
it when installing it.
After charging refrigerant, check for leaks.
Removal and Installation for High-pressure Flexible HoseEJS003YW
REMOVAL
1. Remove the engine under cover.
2. Remove the engine air cleaner and air ducts. Refer to  EM-15, "
AIR CLEANER AND AIR DUCT" .
3. Discharge the refrigerant. Refer to ATC-171, "
HFC-134a (R-134a) Service Procedure" .
4. Remove the high-pressure flexible hose. CAUTION:
Cap or wrap the joint of the pipe 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-pressure flexible hose with a new one, then apply compressor oil to
it when installing it.
After charging refrigerant, check for leaks.
Removal and Installation for High-pressure PipeEJS003YX
REMOVAL
1. Remove the cowl top extension. Refer to  EI-18, "COWL TOP" . 
2. Disconnect the battery negative terminal and positive battery terminal.
3. Reposition the IPDM E/R aside.
4. Remove the front right wheel and tire assembly. Refer to  WT-7, "
Rotation" .
5. Position aside the front floor insulator.
6. Discharge the refrigerant. Refer to ATC-171, "
HFC-134a (R-134a) Service Procedure" .
7. Remove the low pressure pipe. Refer to  ATC-180, "
Removal and Installation for Low-pressure Pipe" .
8. Remove the high-pressure pipe. CAUTION:
Cap or wrap the joint of the pipe 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" .