2006 INFINITI QX56 suspension

NOISE, VIBRATION, AND HARSHNESS (NVH) TROUBLESHOOTINGRFD-7
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RFD
Revision: November 2009 2006 QX56
NOISE, VIBRATION, AND HARSHNESS (NVH) TROUBLESHOOTINGPFP:00003
NVH Troubleshooting ChartEDS0044N
Use the chart below to help you find the cause of the symptom. If necessary, repair or replace these parts.
×: Applicable
Reference page
RFD-23RFD-17RFD-17RFD-18RFD-18RFD-8
PR-3, "
NVH Troubleshooting Chart
"

RAX-4, "
NVH Troubleshooting Chart
"
RSU-5, "
NVH Troubleshooting Chart
"
WT-4, "
NVH Troubleshooting Chart
"
WT-4, "
NVH Troubleshooting Chart
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FAX-4, "
NVH Troubleshooting Chart
"
BR-5, "
NVH Troubleshooting Chart
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PS-5, "
NVH Troubleshooting Chart
"
Possible cause and SUSPECTED PARTS
Gear tooth rough
Gear contact improper
Tooth surfaces worn
Backlash incorrect
Companion flange excessive runout
Gear oil improper
PROPELLER SHAFT
REAR AXLE
REAR SUSPENSION
TIRES
ROAD WHEEL
DRIVE SHAFT
BRAKES
STEERING
Symptom FINAL DRIVE Noise ××××××××××××××

RFD-14
REAR FINAL DRIVE ASSEMBLY
Revision: November 20092006 QX56
7. Place a suitable jack under the rear final drive assembly.
CAUTION:
Do not place the jack on the carrier cover.
8. Remove the nuts and bolts and remove the rear final drive assembly.
CAUTION:
Secure rear final drive assembly to the jack while removing
it.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:

When installing the breather hose make sure the painted marking on the metal end of breather
hose is to the front of the vehicle and there are no pinched or restricted areas on the breather
hose caused by folding or bending when installing it.

When installing the breather hose insert the plastic end of the breather hose into the hole in the
suspension member.

Fill the rear final drive assembly with differential gear oil after installation. Refer to RFD-8, "DIF-
FERENTIAL GEAR OIL" .
WDIA0117E

RSU-1
REAR SUSPENSION
E SUSPENSION
CONTENTS
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SECTION
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RSU
Revision: November 2009 2006 QX56
PRECAUTIONS .....................................................
..... 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ............................................................. ..... 3
Precautions for Rear Suspension ....................... ..... 3
PREPARATION ...................................................... ..... 4
Commercial Service Tools ................................... ..... 4
NOISE, VIBRATION, AND HARSHNESS (NVH)
TROUBLESHOOTING ........................................... ..... 5
NVH Troubleshooting Chart ................................ ..... 5
CAN COMMUNICATION ....................................... ..... 6
System Description ............................................. ..... 6
TROUBLE DIAGNOSIS ......................................... ..... 7
How to Perform Trouble Diagnoses for Quick and
Accurate Repair .................................................. ..... 7
INTRODUCTION .............................................. ..... 7
CLARIFY CONCERN ....................................... ..... 7
WORK FLOW ........................................................ 8
Component Parts and Harness Connector Location ..... 9
Wiring Diagram — A/SUSP — ............................ ... 10
Basic Inspection .................................................. ... 12
AIR HOSES ...................................................... ... 12
POWER SYSTEM TERMINAL LOOSENESS
AND BATTERY INSPECTION ......................... ... 12
CK SUSP INDICATOR LAMP INSPECTION ... ... 12
CK SUSP Indicator Lamp Timing ........................ ... 12
Control Unit Input/Output Signal Standard .......... ... 12
CONSULT-II Function (AIR LEVELIZER) ............ ... 13
CONSULT-II OPERATION ............................... ... 13
SELF-DIAGNOSIS ........................................... ... 14
WORK SUPPORT ............................................ ... 15
DATA MONITOR .............................................. ... 16
ACTIVE TEST .................................................. ... 16
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC
ITEMS .................................................................... ... 18
Height Sensor System Inspection ....................... ... 18
Exhaust Valve Solenoid System Inspection ........ ... 19
Compressor Motor, Compressor Motor Relay and
Circuit Inspection ................................................. ... 21
TROUBLE DIAGNOSES FOR SYMPTOMS ......... ... 24Load Leveling Rear Air Suspension System Does
Not Operate ............................................................ 24
CK SUSP Indicator Lamp Stays On When Ignition
Switch Is Turned On ............................................
... 25
REAR SUSPENSION ASSEMBLY ........................... 26 Components ........................................................ ... 26
On-Vehicle Inspection and Service ...................... ... 27
SHOCK ABSORBER INSPECTION ................. ... 27
Wheel Alignment Inspection ................................ ... 28
PRELIMINARY INSPECTION .......................... ... 28
GENERAL INFORMATION AND RECOMMEN-
DATIONS .......................................................... ... 28
THE ALIGNMENT PROCESS .......................... ... 29
CAMBER .......................................................... ... 29
TOE-IN ............................................................. ... 29
REAR SUSPENSION MEMBER ............................... 31 Removal and Installation ..................................... ... 31
REMOVAL ........................................................ ... 32
INSPECTION AFTER REMOVAL .................... ... 33
INSTALLATION ................................................ ... 34
SHOCK ABSORBER ............................................. ... 35
Removal and Installation ..................................... ... 35
REMOVAL ........................................................ ... 35
INSTALLATION ................................................ ... 35
INSPECTION AFTER INSTALLATION ............. ... 35
SUSPENSION ARM ............................................... ... 36
Removal and Installation ..................................... ... 36
REMOVAL ........................................................ ... 36
INSPECTION AFTER REMOVAL .................... ... 36
INSTALLATION ................................................ ... 37
FRONT LOWER LINK ........................................... ... 38
Removal and Installation ..................................... ... 38
REMOVAL ........................................................ ... 38
INSPECTION AFTER REMOVAL .................... ... 38
INSTALLATION ................................................ ... 39
REAR LOWER LINK & COIL SPRING .................. ... 40
Removal and Installation ..................................... ... 40
REMOVAL ........................................................ ... 40
INSPECTION AFTER REMOVAL .................... ... 41
INSTALLATION ................................................ ... 41

RSU-2Revision: November 20092006 QX56
STABILIZER BAR ..................................................
... 42
Removal and Installation ..................................... ... 42
REMOVAL ........................................................ ... 42
INSPECTION AFTER REMOVAL ..................... ... 42
INSTALLATION ................................................. ... 42
REAR LOAD LEVELING AIR SUSPENSION COM-
PRESSOR ASSEMBLY ............................................ 43 Removal and Installation ..................................... ... 43
REMOVAL ........................................................ ... 43
INSTALLATION ................................................. ... 44HEIGHT SENSOR ..................................................
... 45
Removal and Installation ...................................... ... 45
REMOVAL ......................................................... ... 45
INSTALLATION ................................................. ... 46
CONTROL UNIT ..................................................... ... 47
Removal and Installation ...................................... ... 47
REMOVAL ......................................................... ... 47
INSTALLATION ................................................. ... 47
Initialization Procedure ......................................... ... 47
SERVICE DATA AND SPECIFICATIONS (SDS) ... ... 48
Wheel Alignment .................................................. ... 48
Ball Joint .............................................................. ... 48
Wheelarch Height (Unladen*
1 ) ............................ ... 49

PRECAUTIONSRSU-3
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Revision: November 2009 2006 QX56
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
EES001GX
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 per-
formed by an authorized NISSAN/INFINITI dealer.

Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal 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
harness connectors.
Precautions for Rear SuspensionEES001GY

When installing the rubber bushings, the final tightening must be done under unladen condition and with
the tires on level ground. Oil will shorten the life of the rubber bushings, so wipe off any spilled oil immedi-
ately.

Unladen condition means the fuel tank, engine coolant and lubricants are at the full specification. The
spare tire, jack, hand tools, and mats are in their designated positions.

After installing suspension components, check the wheel alignment.

Caulking nuts are not reusable. Always use new caulking nuts for installation. New caulking nuts are pre-
oiled, do not apply any additional lubrication.

RSU-4
PREPARATION
Revision: November 20092006 QX56
PREPARATIONPFP:00002
Commercial Service ToolsEES001H0
Tool nameDescription
Power tool

Removing wheel nuts

Removing brake caliper assembly

Removing rear suspension component
parts
PBIC0190E

NOISE, VIBRATION, AND HARSHNESS (NVH) TROUBLESHOOTINGRSU-5
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Revision: November 2009 2006 QX56
NOISE, VIBRATION, AND HARSHNESS (NVH) TROUBLESHOOTINGPFP:00003
NVH Troubleshooting ChartEES001H1
Use chart below to help you find the cause of the symptom. If necessary, repair or replace these parts.
×: ApplicableReference page
RSU-26RSU-35
—
—
—
RSU-26
RSU-28RSU-42
PR-3, "
NVH Troubleshooting Chart
"
RFD-7, "
NVH Troubleshooting Chart
"
FAX-4, "
NVH Troubleshooting Chart
"
FSU-4, "
NVH Troubleshooting Chart
"
WT-4, "
NVH Troubleshooting Chart
"
WT-4, "
NVH Troubleshooting Chart
"
RAX-4, "
NVH Troubleshooting Chart
"
PS-5, "
NVH Troubleshooting Chart
"
BR-5, "
NVH Troubleshooting Chart
"
Possible cause and SUSPECTED PARTS
Improper installation, looseness
Shock absorber deformation, damage or deflection
Bushing or mounting deterioration
Parts interference
Spring fatigue
Suspension looseness
Incorrect wheel alignment
Stabilizer bar fatigue
PROPELLER SHAFT
DIFFERENTIAL
FRONT AXLE
FRONT SUSPENSION
TIRES
ROAD WHEEL
DRIVE SHAFT
BRAKES
STEERING
Symptom Noise
×××××× ××× ××××××
Shake ×××× × × × ××××××
Vibration ××××× × × ×× × ×
Shimmy ×××× × × ××× ××
Shudder ××× × ××× ××
Poor quality ride or handling ××××× ×× × ×××

TROUBLE DIAGNOSISRSU-7
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Revision: November 2009 2006 QX56
TROUBLE DIAGNOSISPFP:00000
How to Perform Trouble Diagnoses for Quick and Accurate RepairEES001H3
INTRODUCTION
The rear load leveling air suspension system uses an electronic con-
trol unit to control major functions. The control unit accepts input sig-
nals from the height sensor and controls compressor and exhaust
valve operation.
It is much more difficult to diagnose a rear load leveling air suspen-
sion system problem that occurs intermittently rather than continu-
ously. Most intermittent problems are caused by poor electrical
connections or faulty wiring. In this case, careful checking of suspi-
cious circuits may help prevent the replacement of good parts.
Before undertaking actual checks, take just a few minutes to talk with
a customer who approaches with an air suspension system com-
plaint. The customer is a very good source of information on such
problems, especially intermittent ones. Through discussion with the
customer, find out what symptoms are present and under what con-
ditions they occur.
Start your diagnosis by looking for basic mechanical problems first.
This is one of the best ways to troubleshoot concerns on an air sus-
pension system equipped vehicle. Also check related Service Bulle-
tins for information.
CLARIFY CONCERN

A customer's description of a vehicle concern may vary depend-
ing on the individual. It is important to clarify the customer's con-
cern.

Ask the customer about what symptoms are present under what
conditions. Use this information to reproduce the symptom.
SEF233G
SEF234G
SBR339B