2004 INFINITI QX56 service

SERVICE DATA AND SPECIFICATIONS (SDS)
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RFD
Revision: August 20072004 QX56
Side Bearing Preload Adjustment EDS002JV
SIDE BEARING ADJUSTING WASHERS
Unit: mm (in)
Total Preload AdjustmentEDS002JW
Final drive modelR230 (2 - pinion)
Side bearing preload (reference value) 0.20 − 0.52 N·m (0.02 − 0.05 kg−m, 2 − 4 in-lb)
Drive gear bolt pulling force (by spring gauge) 29.4 − 147 N (3 − 15 kg-f, 22 − 108 lb-f)
Final drive model R230 (2 - pinion)
Adjusting washerThickness Part number Thickness Part number
2.00 (0.0787) 38453 40P00 2.35 (0.0925) 38453 40P07
2.05 (0.0807) 38453 40P01 2.40 (0.0945) 38453 40P08
2.10 (0.0827) 38453 40P02 2.45 (0.0965) 38453 40P09
2.15 (0.0846) 38453 40P03 2.50 (0.0984) 38453 40P10
2.20 (0.0866) 38453 40P04 2.55 (0.1004) 38453 40P11
2.25 (0.0886) 38453 40P05 2.60 (0.1024) 38453 40P12
2.30 (0.0906) 38453 40P06
Final drive modelR230 (2 - pinion)
Total preload with oil seal 2.05 − 4.11 N·m (0.21 − 0.42 kg−m, 19 − 36 in-lb)
Drive gear to drive pinion backlash 0.13 − 0.18 mm (0.0051 − 0.0070 in)

RFD-28
SERVICE DATA AND SPECIFICATIONS (SDS)
Revision: August 20072004 QX56

RSU-1
REAR SUSPENSION
E SUSPENSION
CONTENTS
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SECTION RSU
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RSU
Revision: August 20072004 QX56 PRECAUTIONS .......................................................... 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 3
Precautions for Rear Suspension ............................ 3
Wiring Diagrams and Trouble Diagnosis .................. 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
WORK SUPPORT ............................................... 14
SELF-DIAGNOSIS .............................................. 14
DATA MONITOR ................................................. 15
ACTIVE TEST ..................................................... 16
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC
ITEMS ....................................................................... 17
Height Sensor System Inspection .......................... 17
Exhaust Valve Solenoid System Inspection ........... 19
Compressor Motor, Compressor Motor Relay and Circuit Inspection .................................................... 20
TROUBLE DIAGNOSES FOR SYMPTOMS ............ 23
Load Leveling Rear Air Suspension System Does
Not Operate ............................................................ 23
CK SUSP Indicator Lamp Stays On When Ignition
Switch Is Turned On ............................................... 24
REAR SUSPENSION ASSEMBLY ........................... 25
Components ........................................................... 25
On-Vehicle Inspection and Service ......................... 26
SHOCK ABSORBER INSPECTION .................... 26
Wheel Alignment Inspection ................................... 27
PRELIMINARY INSPECTION ............................. 27
GENERAL INFORMATION AND RECOMMEN-
DATIONS ............................................................. 27
THE ALIGNMENT PROCESS ............................. 28
CAMBER ............................................................. 28
TOE-IN ................................................................ 28
REAR SUSPENSION MEMBER ............................... 30
Removal and Installation ........................................ 30
REMOVAL ........................................................... 31
INSPECTION AFTER REMOVAL ....................... 32
INSTALLATION ................................................... 33
SHOCK ABSORBER ................................................ 34
Removal and Installation ........................................ 34
REMOVAL ........................................................... 34
INSTALLATION ................................................... 34
INSPECTION AFTER INSTALLATION ................ 34
SUSPENSION ARM .................................................. 35
Removal and Installation ........................................ 35
REMOVAL ........................................................... 35
INSPECTION AFTER REMOVAL ....................... 35
INSTALLATION ................................................... 36
FRONT LOWER LINK .............................................. 37
Removal and Installation ........................................ 37
REMOVAL ........................................................... 37
INSPECTION AFTER REMOVAL ....................... 37
INSTALLATION ................................................... 38

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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RSU
Revision: August 20072004 QX56
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
Revision: August 20072004 QX56
PREPARATIONPFP:00002
Commercial Service ToolsEES00110
Tool nameDescription
Power tool

Removing wheel nuts

Removing brake caliper assembly

Removing rear suspension component
parts
PBIC0190E

TROUBLE DIAGNOSIS
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Revision: August 20072004 QX56
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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

RSU-26
REAR SUSPENSION ASSEMBLY
Revision: August 20072004 QX56
Rear Load Leveling Air Suspension System
On-Vehicle Inspection and ServiceEES0011G
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 anchor 2. Stabilizer bar bushing 3. Stabilizer bar clamp
4. Stabilizer bar 5. Connecting rod 6. Front lower link
7. Knuckle 8. Bushing 9. Rear lower link
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
LEIA0072E
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