2005 INFINITI QX4 air suspension

FRONT LOWER LINK
RSU-37
C
D
F
G
H
I
J
K
L
MA
B
RSU
Revision: October 20052005 QX56
FRONT LOWER LINKPFP:55110
Removal and InstallationEES001HL
REMOVAL
1. Remove the wheel and tire assembly using power tool.
2. Use CONSULT-II "EXHAUST SOLENOID" active test to release the air pressure from the rear load level-
ing air suspension system.
3. Remove the shock absorber lower end bolt.
4. Remove the adjusting bolt and nut, and the bolt and nut, from
the front lower link and rear suspension member using power
tool.
5. Remove the front lower link pinch bolt and nut on the knuckle
side using power tool.
6. Disconnect the front lower link from the knuckle using a soft
hammer.
CAUTION:
Do not damage the ball joint with the soft hammer.
7. Remove the front lower link.
INSPECTION AFTER REMOVAL

Check the front lower link and bushing for any deformation, crack, or damage. Replace if necessary.

Check the rubber bushing for damage, cracks and deformation. Replace the front lower link and bushing if
necessary.

Before checking, turn the ball joint at least 10 revolutions so that the ball joint is properly broken in.

Check the ball joint. Replace the front lower link if any of the fol-
lowing conditions exist:
–Ball stud is worn.
–Joint is hard to swing.
–Play in axial direction is excessive.
LEIA0082E
LEIA0086E
Swinging force “A” : Refer to RSU-47, "Ball Joint" .
Turning force “B” : Refer to RSU-47, "
Ball Joint" .
Vertical end play “C” : Refer to RSU-47, "
Ball Joint" .
SFA858A

REAR LOWER LINK & COIL SPRING
RSU-39
C
D
F
G
H
I
J
K
L
MA
B
RSU
Revision: October 20052005 QX56
REAR LOWER LINK & COIL SPRINGPFP:551B0
Removal and Installation EES001HM
REMOVAL
1. Remove the wheel and tire assembly using power tool. Refer to WT-7, "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-42
REAR LOAD LEVELING AIR SUSPENSION COMPRESSOR ASSEMBLY
Revision: October 20052005 QX56
REAR LOAD LEVELING AIR SUSPENSION COMPRESSOR ASSEMBLYPFP:53400
Removal and InstallationEES001HP
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: October 20052005 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: October 20052005 QX56
HEIGHT SENSORPFP:53820
Removal and InstallationEES001HQ
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: October 20052005 QX56
CONTROL UNITPFP:47850
Removal and InstallationEES001HR
REMOVAL
1. Remove the rear LH interior trim panel. Refer to EI-35, "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 ProcedureEES001HS
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: October 20052005 QX56
Wheelarch Height (Unladen*1 )EES001HV
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. If vehicle height is not within ± 10 mm (0.39 in) of the specification, perform the control unit initialization pro-
cedure. Refer to RSU-46, "
Initialization Procedure" . 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: October 20052005 QX56 PRECAUTIONS .......................................................... 2
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 2
PREPARATION ........................................................... 3
Special Service Tool ................................................. 3
Commercial Service Tools ........................................ 3
NOISE, VIBRATION, AND HARSHNESS (NVH)
TROUBLESHOOTING ................................................ 4
NVH Troubleshooting Chart ..................................... 4
WHEEL ....................................................................... 5
Inspection ................................................................. 5
WHEEL AND TIRE ASSEMBLY ................................. 6
Balancing Wheels .................................................... 6
REMOVAL ............................................................. 6
WHEEL BALANCE ADJUSTMENT ...................... 6
Rotation .................................................................... 7
LOW TIRE PRESSURE WARNING SYSTEM ............ 8
System Components ................................................ 8
System Description .................................................. 8
TRANSMITTER ..................................................... 8
REMOTE KEYLESS ENTRY RECEIVER ............. 8
BCM (BODY CONTROL MODULE) ...................... 9
WARNING LAMP AND BUZZER .......................... 9
DISPLAY UNIT ...................................................... 9
CAN COMMUNICATION .......................................... 10
System Description ................................................ 10
TROUBLE DIAGNOSES ...........................................11
Wiring Diagram .......................................................11
BCM Input/Output Signal Standard ........................ 13
ID Registration Procedure ...................................... 14
ID REGISTRATION WITH TRANSMITTER
ACTIVATION TOOL ............................................ 14
ID REGISTRATION WITHOUT TRANSMITTER
ACTIVATION TOOL ............................................ 15
Transmitter Wake Up Operation ............................. 16
WITH TRANSMITTER ACTIVATION TOOL ........ 16
CONSULT-II Function (BCM) ................................. 17
Self-Diagnosis ........................................................ 18DESCRIPTION .................................................... 18
FUNCTION .......................................................... 18
CONSULT-II ......................................................... 18
How to Perform Trouble Diagnosis for Quick and
Accurate Repair ...................................................... 20
INTRODUCTION ................................................. 20
WORK FLOW ...................................................... 20
Preliminary Check .................................................. 21
Malfunction Code/Symptom Chart .......................... 22
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC
ITEMS ........................................................................ 24
Inspection 1: Transmitter or Control Unit (BCM) ..... 24
MALFUNCTION CODE NO. 21, 22, 23 OR 24 ... 24
Inspection 2: Transmitter - 1 ................................... 24
MALFUNCTION CODE NO. 31, 32, 33, 34, 41,
42, 43, 44, 45, 46, 47 OR 48 ............................... 24
Inspection 3: Transmitter - 2 ................................... 25
MALFUNCTION CODE NO. 35, 36, 37 OR 38 ... 25
Inspection 4: Vehicle Speed Signal ........................ 26
MALFUNCTION CODE NO. 52 ........................... 26
TROUBLE DIAGNOSIS FOR SYMPTOMS .............. 27
Inspection 1: Warning Lamp Does Not Come On
When Ignition Switch Is Turned On ........................ 27
Inspection 2: Warning Lamp Stays On When Ignition
Switch Is Turned On ............................................... 27
Inspection 3: Warning Lamp Flashes When Ignition
Switch Is Turned On ............................................... 29
Inspection 4: Hazard Warning Lamp Flashes When
Ignition Switch Is Turned On .................................. 30
Inspection 5: “TIRE PRESSURE” Information In
Display Unit Does Not Exist .................................... 31
Inspection 6: ID Registration Cannot Be Completed ... 31
REMOVAL AND INSTALLATION ............................. 32
Transmitter (Pressure Sensor) ............................... 32
REMOVAL ........................................................... 32
INSTALLATION ................................................... 32
SERVICE DATA AND SPECIFICATIONS (SDS) ...... 34
Road Wheel ............................................................ 34
Tire ......................................................................... 34