low oil pressure INFINITI QX4 2005 Factory Owner's Manual

AT-198
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: October 20052005 QX56
4. CHECK LINE PRESSURE
Check line pressure at the engine stall point. Refer to AT- 5 1 , "
LINE
PRESSURE TEST" .
OK or NG
OK >> GO TO 7.
NG - 1 >> Line pressure high. GO TO 5.
NG - 2 >> Line pressure low. GO TO 6.
5. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT- 2 3 1 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT-262, "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-280, "Oil Pump" .
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
6. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT- 2 3 1 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT-262, "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-280, "Oil Pump" .
–Power train system. Refer to AT-262, "Disassembly" .
–Transmission case. Refer to AT-262, "Disassembly" .
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
7. CHECK A/T FLUID CONDITION
1. Remove oil pan. Refer to AT-231, "
Control Valve With TCM and A/T Fluid Temperature Sensor 2" .
2. Check A/T fluid condition. Refer to AT- 5 0 , "
Fluid Condition
Check" .
OK or NG
OK >> GO TO 8.
NG >> GO TO 11.
SAT4 9 4G
SCIA5199E

AT-200
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: October 20052005 QX56
P1705 THROTTLE POSITION SENSOR" , AT-108, "DTC P0720 VEHICLE SPEED SENSOR A/T
(REVOLUTION SENSOR)" , AT-133, "DTC P1721 VEHICLE SPEED SENSOR MTR" .
NO >> GO TO 3.
3. CHECK A/T FLUID LEVEL
Check A/T fluid level. Refer to AT-13, "
Checking A/T Fluid" .
OK or NG
OK >> GO TO 4.
NG >> Refill ATF.
4. CHECK LINE PRESSURE
Check line pressure at the engine stall point. Refer to AT- 5 1 , "
LINE
PRESSURE TEST" .
OK or NG
OK >> GO TO 7.
NG - 1 >> Line pressure high. GO TO 5.
NG - 2 >> Line pressure low. GO TO 6.
5. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT- 2 3 1 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT-262, "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-280, "Oil Pump" .
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
6. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT- 2 3 1 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT-262, "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-280, "Oil Pump" .
–Power train system. Refer to AT-262, "Disassembly" .
–Transmission case. Refer to AT-262, "Disassembly" .
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
SAT6 3 8A
SAT4 9 4G

TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-205
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Revision: October 20052005 QX56
3. CHECK LINE PRESSURE
Check line pressure at the engine stall point. Refer to AT-51, "
LINE
PRESSURE TEST" .
OK or NG
OK >> GO TO 6.
NG - 1 >> Line pressure high. GO TO 4.
NG - 2 >> Line pressure low. GO TO 5.
4. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT-231, "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT- 2 6 2 , "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-280, "Oil Pump" .
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
5. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT-231, "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT- 2 6 2 , "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-280, "Oil Pump" .
–Power train system. Refer to AT- 2 6 2 , "Disassembly" .
–Transmission case. Refer to AT - 2 6 2 , "Disassembly" .
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
6. CHECK A/T FLUID CONDITION
1. Remove oil pan. Refer to AT-231, "
Control Valve With TCM and A/T Fluid Temperature Sensor 2" .
2. Check A/T fluid condition. Refer to AT- 5 0 , "
Fluid Condition
Check" .
OK or NG
OK >> GO TO 7.
NG >> GO TO 10.
SAT4 9 4G
SCIA5199E

ATC-18
REFRIGERATION SYSTEM
Revision: October 20052005 QX56
REFRIGERATION SYSTEMPFP:KA990
Refrigerant CycleEJS003X1
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 ProtectionEJS003X2
REFRIGERANT PRESSURE SENSOR
The refrigerant system is protected against excessively high 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 pressure 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).

ATC-158
HEATER & COOLING UNIT ASSEMBLY
Revision: October 20052005 QX56
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, "
STEERING COLUMN" .
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-4, "
POWER SUPPLY ROUTING CIRCUIT" .
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-14, "REFILLING ENGINE
COOLANT" .

Recharge the A/C system. Refer to ATC-175, "Evacuating System and Charging Refrigerant" .
REAR HEATER AND COOLING UNIT ASSEMBLY
Removal
1. Discharge the refrigerant from the A/C system. Refer to ATC-175, "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 rear RH interior trim panel. 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-175, "Evacuating System and Charging Refrigerant" .
Removal and Installation for Rear Heater Core PipesEJS00536
REMOVAL
1. Drain the coolant from the engine cooling system. Refer to CO-10, "DRAINING ENGINE COOLANT" .
2. Remove the upper and lower luggage RH side finisher. Refer to EI-35, "
BODY SIDE TRIM"
LJIA0021E

ATC-180
REFRIGERANT LINES
Revision: October 20052005 QX56
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:

Replace the O-ring of the low-pressure flexible hose and high-pressure flexible hose with a new
one, apply compressor oil to the O-rings before installation.

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-179, "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

REFRIGERANT LINES
ATC-183
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Revision: October 20052005 QX56
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-14, "
AIR CLEANER AND AIR DUCT"
3. Remove the cowl top extension. Refer to EI-18, "COWL TOP" .
4. Discharge the refrigerant. Refer to ATC-175, "
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-177, "
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-14, "
AIR CLEANER AND AIR DUCT" .
3. Discharge the refrigerant. Refer to ATC-175, "
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-177, "
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 cable.
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-175, "
HFC-134a (R-134a) Service Procedure" .
7. Remove the low pressure pipe. Refer to ATC-184, "
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-177, "
Components" .

ATC-184
REFRIGERANT LINES
Revision: October 20052005 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-175, "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-177, "
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 A/C PipesEJS00537
REMOVAL
1. Drain the coolant from the engine cooling system. Refer to CO-10, "DRAINING ENGINE COOLANT" .
2. Diconnect the negative battery terminal.
3. Discharge the refrigerant from the A/C system. Refer to ATC-175, "
HFC-134a (R-134a) Service Proce-
dure" .
4. Disconnect the chassis harness connector.
5. Set four suitable jacks at the body mounting points to support the vehicle body when it is seperated from
the frame.
6. Remove the RH body mount bolts. Refer to BL-159, "
Body Mounting"
7. Use the vehicle hoist to lower the frame from the body until there is sufficient clearance for the underfloor
rear high- and low-pressure A/C and heater core pipes from the body.
8. Remove the underfloor rear high- and low-pressure A/C and heater core pipes .
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-177, "
Components" .
CAUTION:

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

After charging refrigerant, check for leaks.
Removal and Installation for Rear A/C PipesEJS00538
REMOVAL
1. Discharge the refrigerant from the A/C system. Refer to ATC-175, "HFC-134a (R-134a) Service Proce-
dure"
2. Remove the upper and lower luggage RH side finisher lower. Refer to EI-35, "BODY SIDE TRIM"
3. Disconnect the rear A/C pipes.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-177, "
Components" .
CAUTION:

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

After charging refrigerant, check for leaks.

REFRIGERANT LINES
ATC-187
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Revision: October 20052005 QX56
2. Remove the defroster mode door arm.
3. Separate the heater core and cooling unit case.
4. Remove the evaporator.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
Replace the O-rings on the low-pressure flexible hose and the high-pressure pipe with new ones.
Apply compressor oil to the O-rings before installing them.
Removal and Installation for Rear EvaporatorEJS003Z2
Rear Heater and Cooling Unit Assembly
LJIA0135E
1. Front cover 2. Evaporator and heater core case 3. Evaporator
4. Side cover 5. Heater core 6. Rear blower motor
7. Blower motor case 8. Rear blower motor resistor

REFRIGERANT LINES
ATC-189
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Revision: October 20052005 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
Perform a visual inspection of all refrigeration parts, fittings, hoses and components for signs of A/C lubricant
leakage, damage, and corrosion. Any A/C lubricant 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 fluo-
rescent 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 lubricants, may falsely trigger the leak detector. Make sure the sur-
faces 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-177, "
Components"
.