2007 INFINITI QX56 air condition

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
RSU-15
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2. Check continuity between height sensor connector C8 terminal
3 and ground.
OK or NG
OK >> GO TO 6.
NG >> Repair harness or connector.
6.CHECK HEIGHT SENSOR SIGNAL CIRCUIT
1. Disconnect suspension control unit connector.
2. Check continuity between height sensor connector C8 terminal
2 and suspension control unit connector B3 terminal 3.
3. Check continuity between height sensor connector C8 terminal
2 and ground.
OK or NG
OK >> Replace the height sensor. Refer to RSU-40.
NG >> Repair harness or connector.
Exhaust Valve Solenoid System InspectionINFOID:0000000003532665
INSPECTION PROCEDURE
1.SELF-DIAGNOSIS RESULT CHECK
Check self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
YES >> If code C1803 was retrieved during self-diagnosis, GO TO 3. If code C1805 was retrieved during
self-diagnosis, GO TO 2.
NO >> Inspection End.
2.CHECK SYSTEM OPERATION
1. Load vehicle to standard laden condition (with driver, front passenger, 2 passengers in second row seats
and no cargo).
2. Conduct active test of "COMPRESSOR" to raise vehicle ride height to +20mm.
CAUTION:3 - Ground Continuity should exist.
WEIA0085E
2 - 3 Continuity should exist.
WEIA0086E
2 - Ground Continuity should not exist.
WEIA0087E
Self-diagnosis results
C1803
C1805

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
RSU-17
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5. Check continuity between suspension air compressor connector
C9 terminal 1 and ground.
OK or NG
OK >> Replace the suspension control unit. Refer to RSU-42.
NG >> Repair harness or connector.
Compressor Motor, Compressor Motor Relay and Circuit InspectionINFOID:0000000003532666
INSPECTION PROCEDURE
1.SELF-DIAGNOSIS RESULT CHECK
Check self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
YES >> If code C1802 was retrieved during self-diagnosis, GO TO 3. If code C1804 or C1808 was
retrieved during self-diagnosis, GO TO 2.
NO >> Inspection End.
2.CHECK SYSTEM OPERATION
1. Load vehicle to standard laden condition (with driver, front passenger, 2 passengers in second row seats
and no cargo).
2. Conduct active test of "EXHAUST SOLENOID" to lower vehicle ride height to -20mm.
3. Return the rear load leveling air suspension system to normal operating mode.
4. Check self-diagnostic results.
Is code C1804 or C1808 displayed again?
YES >> GO TO 3.
NO >> Inspection End.
3.CONNECTOR INSPECTION
1. Disconnect suspension control unit connector B3 and suspension air compressor C9.
2. Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> If code C1804 or C1808 was retrieved during self-diagnosis, GO TO 4. If code C1802 was
retrieved during self-diagnosis, GO TO 6.
NG >> Repair or replace as necessary.
4.AIR HOSE INSPECTION
Inspect for pinched or damaged air hoses between the suspension air reservoir and each load leveling rear air
suspension shock absorber.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace as necessary.
5.SUSPENSION AIR COMPRESSOR INSPECTION1 - Ground Continuity should exist.
WEIA0089E
Self-diagnosis results
C1802
C1804
C1808

RSU-22
< SERVICE INFORMATION >
REAR SUSPENSION ASSEMBLY
Rear Load Leveling Air Suspension System
On-Vehicle Inspection and ServiceINFOID:0000000003532670
Check all of the component mountings for any excessive looseness, or back lash. Check the components for
any excessive wear, damage, or abnormal conditions. Repair or replace the components as necessary.
SHOCK ABSORBER INSPECTION
• Check the shock absorbers for any air leaks or damage, and replace as necessary.
• Check the hoses for any air leaks or damage, and replace as necessary.
10. Shock absorber 11. Suspension arm 12. Lower rubber seat
13. Coil spring 14. Upper rubber seat 15. Rear suspension member
16. Spare tire bracket 17. Bound bumper
AWEIA0076ZZ
1. Rear load leveling air suspension
hose, RH2. Shock absorber, RH 3. Height sensor
4. Rear load leveling air suspension
hose, LH5. Shock absorber, LH 6. Rear load leveling air suspension
compressor assembly
⇐Front

REAR SUSPENSION ASSEMBLY
RSU-23
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Wheel AlignmentInspectionINFOID:0000000003532671
Rear Wheel Alignment Adjusting Bolts
PRELIMINARY INSPECTION
WARNING:
Always adjust the alignment with the vehicle on a flat surface. Use CONSULT-II “EXHAUST SOLE-
NOID” active test to release the air pressure from the rear load leveling air suspension system.
NOTE:
If alignment is out of specification, inspect and replace any damaged or worn rear suspension parts before
making any adjustments.
1. Check and adjust the wheel alignment with the vehicle under unladen conditions. “Unladen conditions”
means that the fuel, coolant, and lubricant are full; and that the spare tire, jack, hand tools and mats are in
their designated positions.
2. Check the tires for incorrect air pressure and excessive wear.
3. Check the wheels for runout and damage. Refer to WT-5, "
Inspection" .
4. Check the wheel bearing axial end play.
5. Check the shock absorbers. Refer to RSU-30, "
Removal and Installation" .
6. Check each mounting point of the suspension components for any excessive looseness or damage.
7. Check each link, arm, and the rear suspension member for any damage.
8. Check the vehicle height. Refer to RSU-44, "
Wheelarch Height (Unladen*1)" .
• If vehicle height is not within ± 10 mm (0.39 in) of the specification, perform the control unit initialization
procedure. Refer to RSU-42, "
Initialization Procedure" .
GENERAL INFORMATION AND RECOMMENDATIONS
1. A Four-Wheel Thrust Alignment should be performed.
• This type of alignment is recommended for any NISSAN vehicle.
• The four-wheel “thrust” process helps ensure that the vehicle is properly aligned and the steering wheel
is centered.
• The alignment machine itself should be capable of accepting any NISSAN vehicle.
• The alignment machine should be checked to ensure that it is level.
2. Make sure the alignment machine is properly calibrated.
• Your alignment machine should be regularly calibrated in order to give correct information.
WEIA0102E
1. Rear lower link adjusting bolt, LH 2. Front lower link adjusting bolt, LH 3. Front lower link adjusting bolt, RH
4. Rear lower link adjusting bolt, RH
Axial end play : 0 mm (0 in)

REAR SUSPENSION MEMBER
RSU-29
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• When installing the upper and lower rubber seats for the rear coil
springs, the arrow embossed on the rubber seats must point out
toward the wheel and tire assembly.
• To connect the rear load leveling air suspension hoses, the lock
ring must be fully seated in the fitting. Insert the hose “B” into the
lock ring “A” until the lock ring “A” is touching the hose “B” as
shown. Pull on the hose to check that it is securely inserted.
• Perform the final tightening of the nuts and bolts for the links (rubber bushing) under unladen condition
(unladen condition means that the fuel tank, engine coolant and lubricants are at the full specification, and
the spare tire, jack, hand tools, and mats are in their designated positions) with the tires on level ground.
• Check the wheel alignment. Refer to FSU-19, "
Wheel Alignment (Unladen*1) *6" .
LEIA0076E
LEIA0078E

RSU-42
< SERVICE INFORMATION >
CONTROL UNIT
CONTROL UNIT
Removal and InstallationINFOID:0000000003532680
REMOVAL
1. Remove the rear LH interior trim panel. Refer to EI-34 .
2. Disconnect the battery negative terminal.
3. Disconnect the suspension control unit electrical connector.
4. Remove the two bolts and remove the suspension control unit.
INSTALLATION
Installation is in the reverse order of removal.
Initialization ProcedureINFOID:0000000003532681
1. If control unit has been replaced, proceed to step 2. If control unit has not been replaced, use CONSULT-
II “CLEAR HEIGHT INI” work support function to clear initialization flag and value. The CK SUSP warning
lamp should illuminate. Using CONSULT-II “EXHAUST SOLENOID” active test, release the air pressure
from the rear load leveling air suspension system.
2. Roll vehicle forward and backward.
3. Use CONSULT-II “ADJUST HEIGHT INI” work support function to set initialization condition.
4. Confirm that CK SUSP warning lamp is OFF.
LEIA0100E
Suspension control unit bolts : 6 N·m (0.6 kg-m, 53 in-lb)

SC-2
< SERVICE INFORMATION >
PRECAUTIONS
SERVICE INFORMATION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000003533312
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 severity 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 whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inoperative, 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 incorrect removal and installation of the SRS, can lead to personal
injury caused by unintentional activation of the system. For removal of Spiral Cable and Air Bag
Module, see the SRS section.
• Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or har-
ness connectors.
Precaution for Power Generation Variable Voltage Control SystemINFOID:0000000003533313
CAUTION:
For this model, the battery current sensor that is installed to the negative battery cable measures the
charging/discharging current of the battery and performs various engine controls. If an electrical com-
ponent is connected directly to the negative battery terminal, the current flowing through that compo-
nent will not be measured by the battery current sensor. This condition may cause a malfunction of
the engine control system and battery discharge may occur. Do not connect an electrical component
or ground wire directly to the battery terminal.

SQUEAK AND RATTLE TROUBLE DIAGNOSIS
SE-5
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SQUEAK AND RATTLE TROUBLE DIAGNOSIS
Work FlowINFOID:0000000003533153
CUSTOMER INTERVIEW
Interview the customer if possible, to determine the conditions that exist when the noise occurs. Use the Diag-
nostic Worksheet during the interview to document the facts and conditions when the noise occurs and any
customer's comments; refer to SE-9, "
Diagnostic Worksheet". This information is necessary to duplicate the
conditions that exist when the noise occurs.
• The customer may not be able to provide a detailed description or the location of the noise. Attempt to obtain
all the facts and conditions that exist when the noise occurs (or does not occur).
• If there is more than one noise in the vehicle, be sure to diagnose and repair the noise that the customer is
concerned about. This can be accomplished by test driving the vehicle with the customer.
• After identifying the type of noise, isolate the noise in terms of its characteristics. The noise characteristics
are provided so the customer, service adviser and technician are all speaking the same language when
defining the noise.
• Squeak —(Like tennis shoes on a clean floor)
Squeak characteristics include the light contact/fast movement/brought on by road conditions/hard surfaces
= higher pitch noise/softer surfaces = lower pitch noises/edge to surface = chirping.
• Creak—(Like walking on an old wooden floor)
Creak characteristics include firm contact/slow movement/twisting with a rotational movement/pitch depen-
dent on materials/often brought on by activity.
• Rattle—(Like shaking a baby rattle)
Rattle characteristics include the fast repeated contact/vibration or similar movement/loose parts/missing
clip or fastener/incorrect clearance.
• Knock —(Like a knock on a door)
Knock characteristics include hollow sounding/sometimes repeating/often brought on by driver action.
• Tick—(Like a clock second hand)
Tick characteristics include gentle contacting of light materials/loose components/can be caused by driver
action or road conditions.
• Thump—(Heavy, muffled knock noise)
Thump characteristics include softer knock/dead sound often brought on by activity.
• Buzz—(Like a bumble bee)
Buzz characteristics include high frequency rattle/firm contact.
• Often the degree of acceptable noise level will vary depending upon the person. A noise that you may judge
as acceptable may be very irritating to the customer.
• Weather conditions, especially humidity and temperature, may have a great effect on noise level.
DUPLICATE THE NOISE AND TEST DRIVE
If possible, drive the vehicle with the customer until the noise is duplicated. Note any additional information on
the Diagnostic Worksheet regarding the conditions or location of the noise. This information can be used to
duplicate the same conditions when you confirm the repair.
SBT842