2006 INFINITI QX56 air condition

RSU-20
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: November 20092006 QX56
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:
The "COMPRESSOR" active test will remain ON until it is turned off using CONSULT-II. Allowing
the compressor to run for an extended period of time may cause damage to air suspension sys-
tem components due to excessive pressure in the air suspension system.
3. Return the rear load leveling air suspension system to normal operating mode.
4. Check self-diagnostic results.
Is code C1805 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 C1805 was retrieved during self-diagnosis, GO TO 4. If code C1803 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. EXHAUST VALVE SOLENOID INSPECTION
Apply 12V to suspension air compressor terminal 2 and ground to
suspension air compressor terminal 1.
OK or NG
OK >> GO TO 6.
NG >> Replace the suspension air compressor. Refer to RSU-
43, "REAR LOAD LEVELING AIR SUSPENSION COM-
PRESSOR ASSEMBLY" .
System air pressure should vent.
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TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMSRSU-21
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Revision: November 2009 2006 QX56
6. CHECK EXHAUST VALVE SOLENOID POWER AND GROUND
1. Reconnect the suspension control unit connector.
2. Turn the ignition switch ON.
3. Check voltage between suspension air compressor connector C9 terminal 2 and ground.
4. Turn ignition switch OFF.
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-47,
"CONTROL UNIT" .
NG >> Repair harness or connector.
Compressor Motor, Compressor Motor Relay and Circuit InspectionEES001HC
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. Voltage
: Approx. 12V
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1 - GroundContinuity should exist.
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Self-diagnosis results
C1802
C1804
C1808

REAR SUSPENSION ASSEMBLYRSU-27
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Revision: November 2009 2006 QX56
Rear Load Leveling Air Suspension System
On-Vehicle Inspection and ServiceEES001HG
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.
1. Seat belt latch anchor2. Stabilizer bar bushing3. Stabilizer bar clamp
4. Stabilizer bar 5. Connecting rod6. Front lower link
7. Knuckle 8. Bushing9. Rear lower link
10. Shock absorber 11. Suspension arm12. Lower rubber seat
13. Coil spring 14. Upper rubber seat15. Rear suspension member
16. Spare tire bracket 17. Bound bumper
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1. Rear load leveling air suspension
hose, RH 2. Shock absorber, RH 3. Height sensor
4. Rear load leveling air suspension hose, LH 5. Shock absorber, LH
6. Rear load leveling air suspension
compressor assembly

RSU-28
REAR SUSPENSION ASSEMBLY
Revision: November 20092006 QX56
Wheel Alignment InspectionEES001HH
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-27, "
SHOCK ABSORBER INSPECTION" .
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-49, "
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-47, "
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.
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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)

RSU-34
REAR SUSPENSION MEMBER
Revision: November 20092006 QX56
INSTALLATION
Installation is in the reverse order of removal.

When raising the rear suspension member assembly, use the
locating pins to align the rear suspension member to the vehicle
body.

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 RSU-48, "Wheel Alignment" .
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RSU-38
FRONT LOWER LINK
Revision: November 20092006 QX56
FRONT LOWER LINKPFP:55110
Removal and InstallationEES001HL
REMOVAL
1. Remove the wheel and tire assembly using power tool.
2. Use CONSULT-II "EXHAUST SOLENOID" active test to release the air pressure from the rear load level-
ing air suspension system.
3. Remove the shock absorber lower end bolt.
4. Remove the adjusting bolt and nut, and the bolt and nut, from the front lower link and rear suspension member using power
tool.
5. Remove the front lower link pinch bolt and nut on the knuckle side using power tool.
6. Disconnect the front lower link from the knuckle using a soft hammer.
CAUTION:
Do not damage the ball joint with the soft hammer.
7. Remove the front lower link.
INSPECTION AFTER REMOVAL

Check the front lower link and bushing for any deformation, crack, or damage. Replace if necessary.

Check the rubber bushing for damage, cracks and deformation. Replace the front lower link and bushing if
necessary.

Before checking, turn the ball joint at least 10 revolutions so that the ball joint is properly broken in.

Check the ball joint. Replace the front lower link if any of the fol-
lowing conditions exist:
–Ball stud is worn.
–Joint is hard to swing.
–Play in axial direction is excessive.
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Swinging force “A” : Refer to RSU-48, "Ball Joint" .
Turning force “B” : Refer to RSU-48, "
Ball Joint" .
Vertical end play “C” : Refer to RSU-48, "
Ball Joint" .
SFA858A

CONTROL UNITRSU-47
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Revision: November 2009 2006 QX56
CONTROL UNITPFP:47850
Removal and InstallationEES001HR
REMOVAL
1. Remove the rear LH interior trim panel. Refer to EI-35, "BODY SIDE TRIM" .
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 ProcedureEES001HS
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.
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Suspension control unit bolts : 6 N·m (0.6 kg-m, 53 in-lb)

SQUEAK AND RATTLE TROUBLE DIAGNOSESSE-5
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Revision: November 2009 2006 QX56
SQUEAK AND RATTLE TROUBLE DIAGNOSESPFP:00000
Work FlowEIS00508
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 sur-
faces = 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
dependent 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.
SBT842