height INFINITI QX56 2004 Factory Repair Manual

REAR FINAL DRIVE ASSEMBLY
RFD-21
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RFD
Revision: August 20072004 QX56
3. Apply genuine medium strength locking sealant or equivalent as
shown. Refer to GI-45, "
Recommended Chemical Products and
Sealants" .

Tighten the drive gear bolts in a criss-cross pattern to specifi-
cation.
4. Press-fit the side bearing inner races on the differential case
using Tools.
INSTALLATION OF DRIVE PINION ASSEMBLY
1. Press-fit the pinion front and rear bearing outer races using
Tools.
2. Select pinion height adjusting washer. Refer to RFD-26, "
Drive Pinion Height Adjustment" . Drive gear bolts
Step 1 : 78.5 N·m (8.0 kg-m, 58 ft-lb)
Step 2 : 34° degrees
SPD5 54
Tool number A: KV38100200 (J-26233)
B: ST33081000 ( — )
SPD3 53
Tool number A: ST15310000 ( — )
B: ST35325000 ( — )
C: ST30621000 ( — )
SPD9 92

RFD-22
REAR FINAL DRIVE ASSEMBLY
Revision: August 20072004 QX56
3. Install the selected pinion height adjusting washer in the drive
pinion. Using a suitable press and Tool, press-fit pinion rear
bearing inner race into the drive pinion.
4. Apply multi-purpose grease to the pinion rear bearing inner race
and pinion front bearing inner race.
5. Set the drive pinion assembly in the differential carrier as shown,
and install drive pinion using a suitable press and suitable tool.
Stop when drive pinion touches the bearing.
6. Install the front oil seal using Tool. Refer to RFD-6, "
Removal and Installation" .
7. Install the companion flange, and tighten the pinion nut to a min-
imum using Tool. Check that the threaded portion of the drive
pinion and drive pinion nut are free of oil or grease.
CAUTION:
The drive pinion nut is not reusable. Use a new drive pinion
nut for installation. Tool number : ST30022000 ( — )
SPD3 77
SDIA0826E
SPD8 96
Tool number : KV40104000 ( — )
SDIA11 45 E

RFD-26
SERVICE DATA AND SPECIFICATIONS (SDS)
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SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
General SpecificationsEDS002JQ
Drive Gear RunoutEDS0 02 JR
Unit: mm (in)
Side Gear Adjustment EDS002JS
Unit: mm (in)
AVAILABLE SIDE GEAR THRUST WASHERS
Unit: mm (in)
Drive Pinion Height AdjustmentEDS002JT
AVAILABLE PINION HEIGHT ADJUSTING WASHERS
Unit: mm (in)
Drive Pinion Preload AdjustmentEDS0 02 JU
Grade2WD 4WD
Final drive modelR230 (2 - pinion)
Gear ratio2.937 : 1 3.357 : 1
Number of teeth (drive gear / drive pinion) 47 / 16 47 / 14
Oil capacity (approx.)
1.75 (3 3/4 US pt, 3 1/8 Imp pt)
Final drive modelR230 (2 - pinion)
Drive gear runout limit 0.05 (0.0020) or less
Final drive modelR230 (2 - pinion)
Clearance limit between side gear and differential case 0.20 (0.0079) or less
Final drive modelR230 (2 - pinion)
Thrust washerThickness Part number
1.75 (0.0688) 38424 7S000
1.80 (0.0708) 38424 7S001
1.85 (0.0728) 38424 7S002
Final drive model R230 (2 - pinion)
Adjusting washerThickness Part number Thickness Part number
2.59 (0.1020) 38154 40P00 2.79 (0.1098) 38154 40P10
2.61 (0.1028) 38154 40P01 2.81 (0.1106) 38154 40P11
2.63 (0.1035) 38154 40P02 2.83 (0.1114) 38154 40P12
2.65 (0.1043) 38154 40P03 2.85 (0.1122) 38154 40P13
2.67 (0.1051) 38154 40P04 2.87 (0.1130) 38154 40P14
2.69 (0.1059) 38154 40P05 2.89 (0.1138) 38154 40P15
2.71 (0.1067) 38154 40P06 2.91 (0.1146) 38154 40P16
2.73 (0.1075) 38154 40P07 2.93 (0.1154) 38154 40P17
2.75 (0.1083) 38154 40P08 2.95 (0.1161) 38154 40P18
2.77 (0.1091) 38154 40P09 2.97 (0.1169) 38154 40P19
Final drive modelR230 (2 - pinion)
Drive pinion preload 1.77 − 2.64 N·m (0.18 − 0.26 kg−m, 16 − 23 in-lb)

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

TROUBLE DIAGNOSIS
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TROUBLE DIAGNOSISPFP:00000
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-12
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Basic InspectionEES00116
AIR HOSES
1. Check for pinched or damaged air hoses between the suspension air reservoir and each load leveling rear
air suspension shock absorber. Reposition, repair or replace hoses as necessary.
2. Check the air hose connections at the suspension air reservoir and at the shock absorbers for leaks. If
connections are leaking, repair or replace hoses as necessary.
POWER SYSTEM TERMINAL LOOSENESS AND BATTERY INSPECTION
Make sure the battery positive cable, negative cable and ground connection are not loose. In addition, make
sure the battery is sufficiently charged.
CK SUSP INDICATOR LAMP INSPECTION
1. Make sure the CK SUSP indicator lamp turns on for approximately 2 seconds when the ignition switch is
turned ON. If it does not, check the combination meter. Refer to DI-5, "
COMBINATION METERS" .
2. Make sure the lamp turns off approximately 2 seconds after the ignition switch is turned ON. If the lamp
does not turn off, conduct self-diagnosis of the suspension control unit.
3. After conducting the self-diagnosis, be sure to erase the error memory. Refer to RSU-13, "
CONSULT-II
Function (AIR LEVELIZER)" .
CK SUSP Indicator Lamp TimingEES00117
X: ON
—: OFF
Control Unit Input/Output Signal StandardEES00118
( ): Wire colorConditionCK SUSP
indicator lampRemarks
Ignition switch OFF – –
Ignition switch ON X Turns off after approximately 2 seconds.
Te r m i n a l
Item ConditionVoltage (V)
(Approx.)
+–
1 (V)
GroundCompressor relay output
Ignition switch ON or STARTBattery voltage
3 (W) Height sensor signal input 0.2V - 4.8V
5 (R) Reference voltage 5V
6 (G/R) Ignition power
Battery voltage
7 (W/L) Battery power —
8 (G/W) Diagnostic K-line — —
9 (SB) Exhaust valve output Ignition switch ON or START Battery voltage
10 (BR) Warning lamp output — —
14 (L) Height sensor ground — —
15 (BR/W) Alternator L signal input Engine running —
16 (B) Suspension control unit ground — 0V

RSU-14
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
6. Select the required operation from the "SELECT DIAG MODE"
screen.
For further information, see the CONSULT-II Operation Manual.
WORK SUPPORT
Operation Procedure
1. Touch “AIR LEVELIZER” on “SELECT SYSTEM” screen.
2. Touch “WORK SUPPORT” on “SELECT DIAG MODE” screen.
3. Touch item on “SELECT WORK ITEM” screen.
4. Touch “START”.
5. The setting will be changed and “ADJUSTMENT COMPLETE” will be displayed.
6. Touch “END”.
Display Item List
SELF-DIAGNOSIS
Description
If an error is detected in the system, perform self-diagnosis as follows:
Operation Procedure
1. Turn ignition switch OFF.
2. Connect CONSULT-II and CONSULT-II CONVERTER to the data link connector.
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carries out CAN communication.
3. Turn ignition switch ON.
4. After stopping the vehicle, with the engine running, touch “START (NISSAN BASED VHCL)”, "AIR LEVEL-
IZER", “SELF-DIAG RESULTS” in order on the CONSULT-II screen.
CAUTION:
If “START (NISSAN BASED VHCL)” is touched immediately after starting the engine or turning on
the ignition switch, "AIR LEVELIZER" might not be displayed in the "SELECT SYSTEM" screen. In
this case, repeat the operation from step 1.
5. The self-diagnostic results are displayed. (If necessary, the self-diagnostic results can be printed out by
touching “COPY”.)

When “NO DTC IS DETECTED” is displayed, check the CK SUSP indicator lamp.
6. Conduct the appropriate inspection from the display item list, and repair or replace the malfunctioning
component.
7. Start and run the vehicle for approximately 1 minute.
8. Turn ignition switch OFF to prepare for erasing the memory.
9. Start the engine and touch “START (NISSAN BASED VHCL)”, "AIR LEVELIZER", “SELF-DIAG
RESULTS”, “ERASE” in order on the CONSULT-II screen to erase the error memory.
If "AIR LEVELIZER" is not indicated, go to GI-39, "
CONSULT-II Data Link Connector (DLC) Circuit" .
BCIA0031E
Item Description
STANDARD HEIGHT LEVEL This mode allows the vehicle height to be set to vehicle height specification within tolerance.
ADJUST HEIGHT INI The initialization value and flag can be set in the suspension control unit in this mode.
CLEAR HEIGHT INI This mode clears the initialization flag and value in the suspension control unit.

TROUBLE DIAGNOSIS
RSU-15
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CAUTION:
If the error memory is not erased, re-conduct the operation from step 7.
10. For the final inspection, start and run the vehicle for approximately 1 minute and confirm that the CK
SUSP indicator lamp is off.
Display Item List
DATA MONITOR
Operation Procedure
1. After turning OFF the ignition switch, connect CONSULT-II and the CONSULT-II CONVERTER to the data
link connector.
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carries out CAN communication.
2. Touch “START (NISSAN BASED VHCL)”, "AIR LEVELIZER", “DATA MONITOR” in order on the CON-
SULT-II screen.
If "AIR LEVELIZER" is not indicated, go to GI-39, "
CONSULT-II Data Link Connector (DLC) Circuit" .
CAUTION:
When “START (NISSAN BASED VHCL)” is touched immediately after starting the engine or turning
on the ignition switch, "AIR LEVELIZER" might not be displayed in the "SELECT SYSTEM" screen.
In this case, repeat the operation from step 2.
3. Return to the "SELECT MONITOR ITEM" screen, and touch "ALL SIGNALS" or "SELECTION FROM
MENU". Refer to the following information.
4. When “START” is touched, the data monitor screen is displayed.
Self-diagnostic item Malfunction detecting condition Check system
Vehicle height sensor
[C1801]Vehicle height sensor voltage is less than 0.2V or greater than
4.8V for more than 60 seconds.Refer to RSU-17, "
Height
Sensor System Inspection" .
Compressor relay
[C1802]1. Driving transistor for compressor relay is off and monitor volt-
age continues high level for more than 10 seconds.
2. Driving transistor for compressor relay is on and monitor volt-
age continues low level for more than 5 seconds.Refer to RSU-20, "
Compres-
sor Motor, Compressor
Motor Relay and Circuit
Inspection" .
Exhaust solenoid
[C1803]1. Driving transistor for exhaust solenoid is off and monitor volt-
age continues high level for more than 10 seconds.
2. Driving transistor for exhaust solenoid is on and monitor volt-
age continues low level for more than 5 seconds.Refer to RSU-19, "
Exhaust
Valve Solenoid System
Inspection" .
Vehicle height adjusting trouble
(compressor)
[C1804]Continuous compressor relay ON time is more than 120 sec-
onds.Refer to RSU-20, "
Compres-
sor Motor, Compressor
Motor Relay and Circuit
Inspection" .
Vehicle height adjusting trouble
(exhaust solenoid)
[C1805]Continuous exhaust solenoid ON time is more than 120 seconds.Refer to RSU-19, "
Exhaust
Valve Solenoid System
Inspection" .
Vehicle height sensor locking trou-
ble
[C1806]Output sensor voltage variation ±0.02V is more than 100 hour
when vehicle height range is normal.Refer to RSU-17, "
Height
Sensor System Inspection" .
Sensor 5V trouble
[C1807]Sensor reference voltage is less than 0.8V or more than 6V for
20 seconds.Refer to RSU-17, "
Height
Sensor System Inspection" .
Integral time trouble by supplying
air
[C1808]Integral discontinuous time on the compressor is more than 180
seconds.Refer to RSU-20, "
Compres-
sor Motor, Compressor
Motor Relay and Circuit
Inspection" .

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
RSU-17
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TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMSPFP:00000
Height Sensor System InspectionEES0011A
INSPECTION PROCEDURE
1. SELF-DIAGNOSIS RESULT CHECK
Check self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
YES >> GO TO 3.
NO >> GO TO 2.
2. DATA MONITOR CHECK
Conduct data monitor of "HEIGT SEN" to check if the status is normal.
OK or NG
OK >> Inspection End.
NG >> GO TO 3.
3. CONNECTOR INSPECTION
1. Turn ignition switch OFF.
2. Disconnect suspension control unit connector B3 and height sensor C8.
3. Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace as necessary.
Self-diagnosis results
C1801
C1806
C1807
HEIGT SEN 0.2V - 4.8V