INFINITI QX56 2004 Factory Service Manual

RSU-2Revision: August 20072004 QX56 REAR LOWER LINK & COIL SPRING ..................... 39
Removal and Installation ........................................ 39
REMOVAL ........................................................... 39
INSPECTION AFTER REMOVAL ........................ 40
INSTALLATION .................................................... 40
STABILIZER BAR ..................................................... 41
Removal and Installation ........................................ 41
REMOVAL ........................................................... 41
INSTALLATION .................................................... 41
Inspection ............................................................... 41
REAR LOAD LEVELING AIR SUSPENSION COM-
PRESSOR ASSEMBLY ............................................ 42
Removal and Installation ........................................ 42
REMOVAL ........................................................... 42
INSTALLATION .................................................... 43HEIGHT SENSOR .....................................................44
Removal and Installation .........................................44
REMOVAL ............................................................44
INSTALLATION ....................................................45
CONTROL UNIT ........................................................46
Removal and Installation .........................................46
REMOVAL ............................................................46
INSTALLATION ....................................................46
Initialization Procedure ............................................46
SERVICE DATA AND SPECIFICATIONS (SDS) ......47
Wheel Alignment .....................................................47
Ball Joint .................................................................47
Wheelarch Height (Unladen*
1 ) ...............................48

PRECAUTIONS
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PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
EES0010X
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.
WA RN ING:

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 SuspensionEES0010Y

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.
Wiring Diagrams and Trouble DiagnosisEES0010Z
When you read wiring diagrams, refer to the following:

GI-15, "How to Read Wiring Diagrams".

PG-4, "POWER SUPPLY ROUTING CIRCUIT" for power distribution circuit.
When you perform trouble diagnosis, refer to the following:

GI-11, "How to Follow Trouble Diagnoses".

GI-27, "How to Perform Efficient Diagnosis for an Electrical Incident".

RSU-4
PREPARATION
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PREPARATIONPFP:00002
Commercial Service ToolsEES00110
Tool nameDescription
Power tool

Removing wheel nuts

Removing brake caliper assembly

Removing rear suspension component
parts
PBIC0190E

NOISE, VIBRATION, AND HARSHNESS (NVH) TROUBLESHOOTING
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NVH Troubleshooting ChartEES00111
Use chart below to help you find the cause of the symptom. If necessary, repair or replace these parts.
×: Applicable Reference page
RSU-25RSU-34
—
—
—
RSU-25
RSU-27RSU-41
PR-3, "
NVH Troubleshooting Chart
"
RFD-5, "
NVH Troubleshooting Chart
"
FAX -4, "
NVH Troubleshooting Chart
" (FAX)
FSU-4, "
NVH Troubleshooting Chart
" (FSU)
WT-3, "
NVH Troubleshooting Chart
"
WT-3, "
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 AND FRONT SUSPENSION
TIRES
ROAD WHEEL
DRIVE SHAFT
BRAKES
STEERING
SymptomNoise×××××× ××× ×××××
Shake×××× × × × ×××××
Vibration××××× × × × × ×
Shimmy×××× × × ×× ××
Shudder ××× × ×× ××
Poor quality ride or handling××××× ×× × ××

RSU-6
CAN COMMUNICATION
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CAN COMMUNICATIONPFP:23710
System DescriptionEES00112
Refer to LAN-5, "CAN COMMUNICATION" .

TROUBLE DIAGNOSIS
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How to Perform Trouble Diagnoses for Quick and Accurate RepairEES00113
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.
SEF 2 33 G
SEF 2 34 G
SBR3 39 B

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TROUBLE DIAGNOSIS
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WORK FLOW
WEIA0077E

TROUBLE DIAGNOSIS
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Component Parts and Harness Connector LocationEES00114
WEIA0140E

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TROUBLE DIAGNOSIS
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Wiring Diagram — A/SUSP —EES00115
WEWA0024E

TROUBLE DIAGNOSIS
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WEWA0042E