low oil pressure INFINITI QX56 2009 Factory Workshop Manual

HA-32
< ON-VEHICLE REPAIR >
COMPRESSOR
 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 ClutchINFOID:0000000003775310
Magnet Clutch Assembly
REMOVAL
1. Remove the compressor. Refer to HA-31, "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 and shims. CAUTION:
Retain all of the shims for installation.
4. Remove the snap ring using a suitable tool.
AWIIA1286GB
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
Revision: December 20092009 QX56

HA-36
< ON-VEHICLE REPAIR >
LOW-PRESSURE FLEXIBLE HOSE
LOW-PRESSURE FLEXIBLE HOSE
Removal and Installation for Low-Pressure Flexible HoseINFOID:0000000003775311
REMOVAL
1. Remove the engine air cleaner and air ducts. Refer to EM-25, "Removal and Installation".
2. Discharge the refrigerant. Refer to HA-20, "HFC-134a (R-134a) Service Procedure"
.
3. Remove the low-pressure flexible hose. CAUTION:
Cap or wrap the joint of the pipe with suitable mate rial such as vinyl tape to avoid the entry of air.
INSTALLATION
Installation is in the reverse order of removal.
Refer to HA-29, "Component"
.
CAUTION:
 Replace the O-ring of the low-pr essure flexible hose with a new one, then apply compressor oil to it
when installing it.
 After charging refrigerant, check for leaks.
Revision: December 20092009 QX56

LOW-PRESSURE PIPEHA-37
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LOW-PRESSURE PIPE
Removal and Installation for Low-Pressure PipeINFOID:0000000003775312
REMOVAL
1. Discharge the refrigerant. Refer to HA-20, "HFC-134a (R-134a) Service Procedure".
2. Remove the cowl top and the cowl top extension. Refer to EXT-18, "Removal and Installation"
.
3. Remove the low-pressure pipe. CAUTION:
Cap or wrap the joint of the pipes with suitable material such as viny l tape to avoid the entry of air.
INSTALLATION
Installation is in the reverse order of removal.
Refer to HA-29, "Component"
.
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
INFOID:0000000003775313
REMOVAL
1. Discharge the refrigerant from the A/C system. Refer to HA-20, "HFC-134a (R-134a) Service Procedure".
2. Drain the coolant from the engine cooling system. Refer to CO-11, "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-pressu re 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).
NOTE:
The remaining steps are performed inside the rear luggage area of the vehicle.
6. Remove the luggage side finisher lower RH. Refer to INT-19, "Removal and Installation"
.
7. Disconnect the rear heater core hoses (1 and 2) from the rear heater core (3).
 : Front
ALIIA0216ZZ
ALIIA0218ZZ
Revision: December 20092009 QX56

HA-38
< ON-VEHICLE REPAIR >
LOW-PRESSURE PIPE
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 variable blower control (2)
 Rear blower motor (3)
 : Front
11. Disconnect the ducts from the rear heater and cooling unit assembly. Refer to HA-29, "Component"
.
12. Remove the rear heater and cooling unit assembly. CAUTION:
Cap or wrap the joint of the pipes with suitable material such as viny l 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 HA-29, "Component"
.
CAUTION:
 Replace the O-rings on the rear high- and low-pr essure A/C pipes with a new ones, then apply com-
pressor oil to them for installation.
 After charging the refrigerant, check for leaks.
Removal and Installation for Underfloor Rear High- and Lo w-Pressure A/C and Heater
Core Pipes
INFOID:0000000003775314
REMOVAL
1. Drain the engine coolant. Refer to CO-11, "Changing Engine Coolant".
2. Disconnect the battery negative terminal.
3. Disconnect the generator harness.
4. Discharge the refrigerant. Refer to HA-20, "HFC-134a (R-134a) Service Procedure"
.
ALIIA0219ZZ
ALIIA0220ZZ
ALIIA0221ZZ
Revision: December 20092009 QX56

LOW-PRESSURE PIPEHA-39
< ON-VEHICLE REPAIR >
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5. Remove the front and rear bumper fascia. Refer to EXT-13, "Removal and Installation" (front), EXT-15,
"Removal and Installation" (rear).
6. Reposition the front fender protec tor out of the way. Refer to EXT-23, "Removal and Installation"
.
7. Disconnect the chassis harness connector.
8. Remove the spare wheel and tire.
9. Remove the tailpipe and tailpipe hanger bracket. Refer to EX-6, "Removal and Installation"
.
10. Remove the seatbelt latch anchor. Refer to EX-6, "Removal and Installation"
.
11. Remove the front floor heat shield.
12. Disconnect each end of the underfloor rear high- and low-pressure A/C and heater core pipes. Refer to
HA-29, "Component"
.
CAUTION:
Cap or wrap the joint of the pipes with suitable material such as viny l tape to avoid the entry of air.
13. Set two suitable jacks at the RH body mount points to support the vehicle body when it is separated from the RH side of the frame.
14. Remove the RH body mount bolts. Refer to BRM-6, "Body Mounting"
.
15. Use the vehicle hoist to lower the RH side of the frame from the RH side of the body [approximately 305
mm (12 in)] until there is suffici ent clearance to remove the underfloor rear high- and low-pressure A/C
and heater core pipes from between the body and the frame.
16. Remove the underfloor rear high- and low-pressure A/ C and heater core pipes from the back of the vehi-
cle.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
 Replace the O-rings of the underfloor rear high - and low-pressure A/C and heater core pipes with
new ones, then apply compressor oil to them for installation.
 After charging refrigerant, check for leaks.
Revision: December 20092009 QX56

HIGH-PRESSURE PIPEHA-41
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HIGH-PRESSURE PIPE
Removal and Installation for High-Pressure PipeINFOID:0000000003775316
REMOVAL
1. Remove the cowl top extension. Refer to EXT-18, "Removal and Installation".
2. Disconnect the battery negative termi nal and positive battery terminal.
3. Reposition the IPDM E/R aside.
4. Remove the front left wheel and tire assembly. Refer to MA-29, "Rotation"
.
5. Position aside the front floor insulator.
6. Discharge the refrigerant. Refer to HA-20, "HFC-134a (R-134a) Service Procedure"
.
7. Remove the low pressure pipe. Refer to HA-37, "Removal and Installation for Low-Pressure Pipe"
.
8. Remove the high-pressure pipe. CAUTION:
Cap or wrap the joint of the pipe with suitable mate rial such as vinyl tape to avoid the entry of air.
INSTALLATION
Installation is in the reverse order of removal.
Refer to HA-29, "Component"
.
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 Rear High- and Low-Pressure A/C and Heater Core Pipes
INFOID:0000000003775317
REMOVAL
1. Discharge the refrigerant from the A/C system. Refer to HA-20, "HFC-134a (R-134a) Service Procedure".
2. Drain the coolant from the engine cooling system. Refer to CO-11, "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-pressu re 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).
NOTE:
The remaining steps are performed inside the rear luggage area of the vehicle.
6. Remove the luggage side finisher lower RH. Refer to INT-19, "Removal and Installation"
.
7. Disconnect the rear heater core hoses (1 and 2) from the rear heater core (3).
 : Front
ALIIA0216ZZ
ALIIA0218ZZ
Revision: December 20092009 QX56

HA-42
< ON-VEHICLE REPAIR >
HIGH-PRESSURE PIPE
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 variable blower control (2)
 Rear blower motor (3)
 : Front
11. Disconnect the ducts from the rear heater and cooling unit assembly. Refer to HA-29, "Component"
.
12. Remove the rear heater and cooling unit assembly. CAUTION:
Cap or wrap the joint of the pipes with suitable material such as viny l 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 HA-29, "Component"
.
CAUTION:
 Replace the O-rings on the rear high- and low-pr essure A/C pipes with a new ones, then apply com-
pressor oil to them for installation.
 After charging the refrigerant, check for leaks.
Removal and Installation for Underfloor Rear High- and Lo w-Pressure A/C and Heater
Core Pipes
INFOID:0000000003775318
REMOVAL
1. Drain the engine coolant. Refer to CO-11, "Changing Engine Coolant".
2. Disconnect the battery negative terminal.
3. Disconnect the generator harness.
4. Discharge the refrigerant. Refer to HA-20, "HFC-134a (R-134a) Service Procedure"
.
ALIIA0219ZZ
ALIIA0220ZZ
ALIIA0221ZZ
Revision: December 20092009 QX56

HIGH-PRESSURE PIPEHA-43
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5. Remove the front and rear bumper fascia. Refer to EXT-13, "Removal and Installation" (front), EXT-15,
"Removal and Installation" (rear).
6. Reposition the front fender protec tor out of the way. Refer to EXT-23, "Removal and Installation"
.
7. Disconnect the chassis harness connector.
8. Remove the spare wheel and tire.
9. Remove the tailpipe and tailpipe hanger bracket. Refer to EX-6, "Removal and Installation"
.
10. Remove the seatbelt latch anchor. Refer to EX-6, "Removal and Installation"
.
11. Remove the front floor heat shield.
12. Disconnect each end of the underfloor rear high- and low-pressure A/C and heater core pipes. Refer to
HA-29, "Component"
.
CAUTION:
Cap or wrap the joint of the pipes with suitable material such as viny l tape to avoid the entry of air.
13. Set two suitable jacks at the RH body mount points to support the vehicle body when it is separated from the RH side of the frame.
14. Remove the RH body mount bolts. Refer to BRM-6, "Body Mounting"
.
15. Use the vehicle hoist to lower the RH side of the frame from the RH side of the body [approximately 305
mm (12 in)] until there is suffici ent clearance to remove the underfloor rear high- and low-pressure A/C
and heater core pipes from between the body and the frame.
16. Remove the underfloor rear high- and low-pressure A/ C and heater core pipes from the back of the vehi-
cle.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
 Replace the O-rings of the underfloor rear high - and low-pressure A/C and heater core pipes with
new ones, then apply compressor oil to them for installation.
 After charging refrigerant, check for leaks.
Revision: December 20092009 QX56

REFRIGERATION SYSTEMHAC-11
< FUNCTION DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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REFRIGERATION SYSTEM
Refrigerant CycleINFOID:0000000004040375
REFRIGERANT FLOW
The refrigerant flows in the standard pattern, that is, through the compressor, the condenser with liquid tank,
through the front and rear evaporators, and back to the compressor. The refrigerant evaporation through the
evaporator coils are controlled by front and rear externally equalized expansion valves, located inside the front
and rear evaporator cases.
Refrigerant System ProtectionINFOID:0000000004040376
REFRIGERANT PRESSURE SENSOR
The refrigerant system is protected against excessively hi gh or low pressures by the refrigerant pressure sen-
sor, located on the condenser. If the system pressure rises above or falls below the specifications, the refriger-
ant pressure sensor detects the pressure inside the refrigerant line and sends a voltage signal to the ECM.
The ECM de-energizes the A/C relay to disengage the magnetic compressor clutch when pressure on the high
pressure side detected by refrigerant pressu re sensor is over about 2,746 kPa (28 kg/cm
2, 398 psi), or below
about 120 kPa (1.22 kg/cm
2, 17.4 psi).
PRESSURE RELIEF VALVE
The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor.
When the pressure of refrigerant in the system incr eases to an abnormal level [more than 2,990 kPa (30.5 kg/
Revision: December 20092009 QX56

INSUFFICIENT COOLINGHAC-115
< SYMPTOM DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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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
High-pressure Side is Too Low and Low-pressure Side is Too High
Gauge indication Refrigerant cycleProbable causeCorrective action
Both high- and low-pressure sides
are too high. Pressure is reduced soon af-
ter water is splashed on con-
denser.
Excessive refrigerant charge in
refrigeration cycle
Reduce refrigerant until speci-
fied pressure is obtained.
Air suction by cooling fan is in-
sufficient. 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 val-
ue quickly drops by approx-
imately 196 kPa (2 kg/cm
2 ,
28 psi). It then decreases
gradually thereafter. Poor heat exchange in con-
denser
(After compressor operation
stops, high-pressure decreas-
es too slowly.)
↓
Air in refrigeration cycle
Evacuate and recharge system.
Engine tends to overheat. Engine cooling systems mal-
function. Check and repair engine cool-
ing system.
• An area of the low-pressure 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 lit- tle compared with the speci-
fication.
↓
Improper expansion valve ad-
justment 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 lo-
cated between compressor
and condenser are clogged or
crushed.
• Check and repair or replace
malfunctioning parts.
• Check oil for contamination.
AC360A
Revision: December 20092009 QX56