suspension INFINITI QX56 2004 Factory Repair Manual

REAR LOWER LINK & COIL SPRING
RSU-39
C
D
F
G
H
I
J
K
L
MA
B
RSU
Revision: August 20072004 QX56
REAR LOWER LINK & COIL SPRINGPFP:551B0
Removal and Installation EES0011P
REMOVAL
1. Remove the wheel and tire assembly using power tool. Refer to WT-6, "Rotation" .
2. Use CONSULT-II "EXHAUST SOLENOID" active test to release the air pressure from the rear load level-
ing air suspension system.
3. For removing the LH rear lower link and coil spring, remove the
height sensor arm bracket bolt from the LH rear lower link.
4. Set a suitable jack to relieve the coil spring tension from the rear
lower link.
WAR NIN G:
Do not compress the coil spring when setting the jack.
5. Loosen the rear lower link adjusting bolt and nut connected to
the rear suspension member, using power tool.
6. Remove the rear lower link bolt and nut from the knuckle using
power tool.
7. Slowly lower the suitable jack to release the coil spring tension. Then remove the upper rubber seat, coil
spring, and lower rubber seat from the rear lower link.
LEIA0080E
LEIA0077E
LEIA0009E
LEIA0077E

RSU-40
REAR LOWER LINK & COIL SPRING
Revision: August 20072004 QX56
8. Remove the rear lower link adjusting bolt and nut from the rear
suspension member using power tool, then remove the rear
lower link.
INSPECTION AFTER REMOVAL
Check the coil spring and rubber seats for deformation, cracks, or other damage and replace if necessary.
INSTALLATION
Installation is in the reverse order of removal.

Tighten the nuts and bolts to specification. Refer to RSU-25, "Components" .

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.

After installing the rear lower link and coil spring, check the
wheel alignment and adjust if necessary. Refer to RSU-27,
"Wheel Alignment Inspection" .
LEIA0009E
LEIA0076E

RSU-42
REAR LOAD LEVELING AIR SUSPENSION COMPRESSOR ASSEMBLY
Revision: August 20072004 QX56
REAR LOAD LEVELING AIR SUSPENSION COMPRESSOR ASSEMBLYPFP:53400
Removal and InstallationEES0011T
Rear Load Leveling Air Suspension System
REMOVAL
1. Use CONSULT-II "EXHAUST SOLENOID" active test to release the air pressure from the rear load level-
ing air suspension system.
2. Disconnect the electrical connectors for the rear load leveling air suspension compressor assembly.
3. Unclip the rubber cover to access the rear load leveling air suspension compressor assembly.
4. Disconnect the rear load leveling air suspension hoses at the
rear load leveling air suspension compressor assembly.

To disconnect the hoses, push in on the lock ring using a suit-
able tool and pull the hose out.
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
LEIA0074E

REAR LOAD LEVELING AIR SUSPENSION COMPRESSOR ASSEMBLY
RSU-43
C
D
F
G
H
I
J
K
L
MA
B
RSU
Revision: August 20072004 QX56
5. Remove the four bolts that mount the rear load leveling air sus-
pension compressor assembly to the underbody.
INSTALLATION
Installation is in the reverse order of removal.

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.
LEIA0090E
LEIA0078E

RSU-44
HEIGHT SENSOR
Revision: August 20072004 QX56
HEIGHT SENSORPFP:53820
Removal and InstallationEES0011U
Rear Load Leveling Air Suspension System
REMOVAL
1. Use CONSULT-II “EXHAUST SOLENOID” active test to release the air pressure from the rear load level-
ing air suspension system.
2. Disconnect the electrical connector for the height sensor.
3. Remove the two height sensor bolts and height sensor arm
bracket bolt.
4. Remove the height sensor.
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
LEIA0080E

RSU-46
CONTROL UNIT
Revision: August 20072004 QX56
CONTROL UNITPFP:47850
Removal and InstallationEES0011V
REMOVAL
1. Remove the rear LH interior trim panel. Refer to EI-34, "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 ProcedureEES0011W
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.
LEIA0100E
Suspension control unit bolts : 6 N·m (0.6 kg-m, 53 in-lb)

RSU-48
SERVICE DATA AND SPECIFICATIONS (SDS)
Revision: August 20072004 QX56
Wheelarch Height (Unladen*1 )EES0011Z
Unit: mm (in)
*1: Fuel, engine coolant and engine oil full. Spare tire, jack, hand tools and mats in designated positions.
*2: Verify the vehicle height using Consult-II memory register 1103 and set rear wheelarch height to 0 ± 10 mm (0 ± 0.39 in) as neces-
sary.Suspension type
Air leveling*
2
Applied model4x2 4x4
Front wheelarch height (Hf)913
(35.94)931
(36.65)
Rear wheelarch height (Hr)912
(35.91)932
(36.69)
LEIA0085E

WT-1
ROAD WHEELS & TIRES
E SUSPENSION
CONTENTS
C
D
F
G
H
I
J
K
L
M
SECTION WT
A
B
WT
Revision: August 20072004 QX56 PREPARATION ........................................................... 2
Special Service Tool ................................................. 2
Commercial Service Tools ........................................ 2
NOISE, VIBRATION, AND HARSHNESS (NVH)
TROUBLESHOOTING ................................................ 3
NVH Troubleshooting Chart ..................................... 3
WHEEL ....................................................................... 4
Inspection ................................................................. 4
WHEEL AND TIRE ASSEMBLY ................................. 5
Balancing Wheels .................................................... 5
REMOVAL ............................................................. 5
WHEEL BALANCE ADJUSTMENT ...................... 5
Rotation .................................................................... 6
LOW TIRE PRESSURE WARNING SYSTEM ............ 7
System Components ................................................ 7
System Description .................................................. 7
TRANSMITTER ..................................................... 7
REMOTE KEYLESS ENTRY RECEIVER ............. 7
BCM (BODY CONTROL MODULE) ...................... 8
LOW TIRE PRESSURE WARNING LAMP AND
BUZZER ................................................................ 8
DISPLAY UNIT ...................................................... 8
CAN COMMUNICATION ............................................ 9
System Description .................................................. 9
TROUBLE DIAGNOSES .......................................... 10
Wiring Diagram — T/WARN — .............................. 10
Terminal and Reference Value (BCM) .................... 12
ID Registration Procedure ...................................... 13
ID REGISTRATION WITH TRANSMITTER
ACTIVATION TOOL ............................................ 13
ID REGISTRATION WITHOUT TRANSMITTER
ACTIVATION TOOL ............................................ 14
Transmitter Wake Up Operation ............................. 15
............................................................................ 15
CONSULT-II Function (BCM) ................................. 16
Self-Diagnosis ........................................................ 17
DESCRIPTION .................................................... 17
FUNCTION .......................................................... 17CONSULT-II ......................................................... 17
How to Perform Trouble Diagnosis for Quick and
Accurate Repair ...................................................... 19
INTRODUCTION ................................................. 19
WORK FLOW ...................................................... 19
Preliminary Check .................................................. 20
Malfunction Code/Symptom Chart .......................... 21
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC
ITEMS ........................................................................ 23
Inspection 1: Transmitter or Control Unit (BCM) ..... 23
MALFUNCTION CODE NO. 21, 22, 23 OR 24 ... 23
Inspection 2: Transmitter - 1 ................................... 23
MALFUNCTION CODE NO. 31, 32, 33, 34, 41,
42, 43, 44, 45, 46, 47 OR 48 ............................... 23
Inspection 3: Transmitter - 2 ................................... 24
MALFUNCTION CODE NO. 35, 36, 37 OR 38 ... 24
Inspection 4: Vehicle Speed Signal ........................ 25
MALFUNCTION CODE NO. 52 ........................... 25
TROUBLE DIAGNOSIS FOR SYMPTOMS .............. 26
Inspection 1: Low Tire Pressure Warning Lamp
Does Not Come On When Ignition Switch Is Turned
On ........................................................................... 26
Inspection 2: Low Tire Pressure Warning Lamp
Stays On When Ignition Switch Is Turned On ......... 26
Inspection 3: Low Tire Pressure Warning Lamp
Flashes When Ignition Switch Is Turned On .......... 28
Inspection 4: Hazard Warning Lamp Flashes When
Ignition Switch Is Turned On .................................. 29
Inspection 5: “TIRE PRESSURE” Information In
Display Unit Does Not Exist .................................... 30
Inspection 6: ID Registration Cannot Be Completed ... 30
REMOVAL AND INSTALLATION ............................. 31
Transmitter (Pressure Sensor) ............................... 31
REMOVAL ........................................................... 31
INSTALLATION ................................................... 31
SERVICE DATA AND SPECIFICATIONS (SDS) ...... 33
Road Wheel ............................................................ 33
Tire ......................................................................... 33

NOISE, VIBRATION, AND HARSHNESS (NVH) TROUBLESHOOTING
WT-3
C
D
F
G
H
I
J
K
L
MA
B
WT
Revision: August 20072004 QX56
NOISE, VIBRATION, AND HARSHNESS (NVH) TROUBLESHOOTINGPFP:00003
NVH Troubleshooting ChartEES00122
Use the chart below to help you find the cause of the symptom. If necessary, repair or replace these parts.
×: ApplicableReference page
WT-4WT-5WT-33WT-6—
—
WT-33
RFD-5, "
NVH Troubleshooting Chart
" (FFD),
RFD-5, "
NVH Troubleshooting Chart
" (RFD)
FAX -4, "
NVH Troubleshooting Chart
" (FAX),
FSU-4, "
NVH Troubleshooting Chart
" (FSU)
RAX-4, "
NVH Troubleshooting Chart
" (RAX),
RSU-5, "
NVH Troubleshooting Chart
" (RSU)
Refer to TIRES in this chart.
Refer to ROAD WHEEL in this chart.
BR-5, "
NVH Troubleshooting Chart
"
PS-5, "
NVH Troubleshooting Chart
"
Possible cause and SUSPECTED PARTS
Out-of-round
Imbalance
Incorrect tire pressure
Uneven tire wear
Deformation or damage
Non-uniformity
Incorrect tire size
DIFFERENTIAL
FRONT AXLE AND FRONT SUSPENSION
REAR AXLE AND REAR SUSPENSION
TIRES
ROAD WHEEL
BRAKE
STEERING
SymptomTIRESNoise× ××××× × × × × ××
Shake××××× × ××× ××
Vibration××××××
Shimmy× ×××××× × × × ××
Shudder××××× × ××× ××
Poor quality ride or
handling××××× × ×××
ROAD
WHEELNoise×× × ××× ×××
Shake×× × ×× ×××
Shimmy, shudder×× × ×× ×××
Poor quality ride or
handling×× × ×× ×

WT-4
WHEEL
Revision: August 20072004 QX56
WHEELPFP:40300
InspectionEES00123
1. Check tires for wear and improper inflation.
2. Check wheels for deformation, cracks and other damage. If
deformed, remove wheel and check wheel runout.
a. Remove tire from wheel and mount wheel on a tire balance
machine.
b. Set dial indicator as shown in the illustration. Refer to WT-33,
"Road Wheel" .
3. Check front wheel bearings for looseness.
4. Check front suspension for looseness.
SFA975B