2008 INFINITI QX56 Electrical

PRECAUTIONSHA-3
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000004884163
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
• When working near the Airbag Diagnosis Sensor Un it or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or el ectric power tools or strike near the sensor(s) with a
hammer. Heavy vibration could activate the sensor( s) and deploy the air bag(s), possibly causing
serious injury.
• When using air or electric power tools or hammers, always switch the Ignition OFF, disconnect the battery, and wait at least 3 minutes before performing any service.
Precaution Necessary for Steering Wheel Rotation After Battery Disconnect
INFOID:0000000004884164
NOTE:
• This Procedure is applied only to models with Intelligent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
• Remove and install all control units after disconnecti ng both battery cables with the ignition knob in the
″ LOCK ″ position.
• Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS , an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery power is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be
rotated.
4. Perform the necessary repair operation.
Revision: March 2010 2008 QX56

HA-26
< ON-VEHICLE MAINTENANCE >
ELECTRICAL LEAK DETECTOR
ELECTRICAL LEAK DETECTOR
Checking of Refrigerant LeaksINFOID:0000000001516649
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 el ectronic 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 l eak detector probe slower and closer to the suspected leak area will
improve the chances of finding a leak.
Electronic Refrigerant Leak DetectorINFOID:0000000001516650
PRECAUTIONS FOR HANDLING LEAK DETECTOR
NOTE:
When performing a refrigerant leak check, use a electr onic refrigerant leak detector (J-41995) or equivalent.
Ensure that the electronic refrigerant leak detector (J-41995) is calibrated and set properly according to the
manufacturer's operating instructions.
The electronic refrigerant leak detector (J-41995) is a delicate
device. To use the electronic refrigerant leak detector (J-41995)
properly, read the manufacturer's operating instructions and perform
any specified maintenance.
1. Position the probe approximately 5 mm (3/16 in) away from the point to be checked as shown.
AHA281A
SHA707EA
Revision: March 2010 2008 QX56

ELECTRICAL LEAK DETECTORHA-27
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2. When checking for leaks, circle each fitting completely with the probe as shown.
3. Move the probe along each component at a speed of approxi- mately 25 - 50 mm (1 - 2 in)/second as shown.
CHECKING PROCEDURE
NOTE:
To prevent inaccurate or false readings, make sure t here is no refrigerant vapor, shop chemicals, or cigarette
smoke in the vicinity of the vehicle. Perform the leak test in a calm area (low air/wind movement) so that the
leaking refrigerant is not dispersed.
1. Turn the engine OFF.
2. Connect the manifold gauge set (J-39183-C) to the A/C service ports. Refer to HA-20, "
HFC-134a (R-
134a) Service Procedure".
3. Check if the A/C refrigerant pressu re is at least 345 kPa (3.52 kg/cm
2 , 50 psi) above a temperature of
16° C (61° F). If less than specification, recover/ev acuate and recharge the system with the specified
amount of refrigerant. Refer to HA-20, "
HFC-134a (R-134a) Service Procedure".
NOTE:
At temperatures below 16 °C (61° F), leaks may not be detected sinc e the system may not reach 345 kPa
(3.52 kg/cm
2 , 50 psi) pressure.
4. Perform the leak test from the high-pressure side (front A/C compressor discharge “a” to evaporator inlet “f” or rear piping connection “l”) to the low-pressure side (front A/C evaporator drain hose “g” to shaft seal
“k” and rear A/C evaporator drain hose “o” to piping connection “r”). Refer to HA-29, "
Component". Clean
the component to be checked and carefully move the electronic refrigerant leak detector probe completely
around the following connections and components.
• Check the compressor shaft seal
• Check the high and low-pressure pipe and hose fitt ings, relief valve, and compressor shaft seal
• Check the liquid tank
• Check the refrigerant pressure sensor
• Check all around the service valves. Check that the service valve caps are screwed tightly on the ser-
vice valves (to prevent leaks).
NOTE:
After removing manifold gauge set (J-39183-C) from the service valves, wipe any residue from the ser-
vice valves to prevent any false readings by the electronic refrigerant leak detector (J-41995).
• Evaporator
With engine OFF, turn blower fan on “High” for at least 15 seconds to dissipate any refrigerant trace in
the heater and cooling unit assembly. Wait a minimum of 10 minutes accumulation time (refer to the
manufacturer's recommended procedure for actual wait time) before inserting the electronic refrigerant
leak detector probe into the heater and cooling unit assembly drain hose.
NOTE:
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HA-28
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ELECTRICAL LEAK DETECTOR
Keep the probe inserted for at least 10 seconds. Use caution not to contaminate the probe tip with water
or dirt that may be in the drain hose.
5. If a leak is detected, verify at least once by blowing compressed air into the area of the suspected leak, then repeat the leak check.
6. Do not stop when one leak is found. Continue to check for additional leaks at all system components and connections.
7. If no leaks are found, perform steps 8 - 11.
8. Start the engine.
9. Set the heater A/C controls as follows: NOTE:
For the automatic system, turn OF F the automatic controls and set the heater A/C controls manually.
a. A/C switch to ON
b. Air flow to VENT mode
c. Intake position to RECIRCULATION mode
d. Temperature to MAX cold
e. Blower fan speed to HIGH
10. Run the engine at 1,500 rpm for at least 2 minutes.
11. Turn the engine OFF and perform the leak check again following steps 4 through 6 above.
Refrigerant leaks should be checked immediately after turning
the engine OFF. Begin with the leak detector at the compressor.
The pressure on the high pressure side will gradually drop after
the refrigerant circulation stops and pressure on the low pres-
sure side will gradually rise, as shown in the graph. Some leaks
are more easily detected when the pressure is high.
12. Before connecting the recovery/recycling equipment to the vehicle, check the recovery/recycling equip-
ment gauges. No refrigerant pressure should be displayed. If pressure is displayed, recover the refriger-
ant from the equipment lines and t hen check the refrigerant purity.
13. Confirm refrigerant purity in supply tank using recovery/recycling equipment and refrigerant identifier
equipment (J-41810-NI).
14. Confirm the refrigerant purity in the vehicle's A/C system using recovery/recycling equipment and refriger-
ant identifier equipment (J-41810-NI).
15. Discharge the A/C system using recovery/recycling equipment. Repair the leaking fitting or component as
necessary.
16. Evacuate and recharge the A/C system and perform the leak test to confirm th\
at there are no refrigerant leaks.
17. Conduct the Operational Check to ensure system works properly. Refer to HAC-108,
"SymptomMatrixChart" and HAC-110, "Diagnostic Work Flow".
SHA839E
Revision: March 2010 2008 QX56

COMPRESSORHA-31
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COMPRESSOR
Removal and Installation for CompressorINFOID:0000000001516652
A/C Compressor Mounting
REMOVAL
1. Discharge the refrigerant. Refer to HA-20, "HFC-134a (R-134a) Service Procedure".
2. Remove the front left wheel and tire assembly. Refer to WT-48, "
Rotation".
3. Remove the engine under cover.
4. Remove front fender protector. Refer to EXT-23, "
Removal and Installation"
5. Remove the engine air cleaner and air ducts. Refer to EM-25, "Removal and Installation".
6. Remove the drive belt. Refer to EM-13, "
Removal and Installation".
7. Disconnect the compressor electrical connector.
8. Disconnect the high-pressure flexible hose and low-pressure flexible hose from the compressor. CAUTION:
Cap or wrap the joint of the pipe with suitable mate rial such as vinyl tape to avoid the entry of air.
9. Remove the compressor bolts and nut using power tools.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
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HA-38
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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 Installati on for Underfloor Rear High- and Low-Pressure A/C and Heater
Core Pipes
INFOID:0000000002975447
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".
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HA-42
< ON-VEHICLE REPAIR >
HIGH-PRESSURE PIPE
7. Disconnect the rear heater core hoses (1 and 2) from the rearheater core (3).
• : Front
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:
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Revision: March 2010 2008 QX56

AMBIENT SENSORHA-45
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AMBIENT SENSOR
Removal and InstallationINFOID:0000000001516659
REMOVAL
1. Disconnect the ambient sensor electrical connector. NOTE:
The ambient sensor (1) is located behind the front bumper, in
front of the condenser.
2. Release the ambient sensor clip and then remove the ambient sensor (1).
INSTALLATION
Installation is in the reverse order of removal.
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Revision: March 2010 2008 QX56