2004 INFINITI QX56 suspension

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